大多數商業用照明燈具，由於含有藍光的威脅，因此，沒有合理化使用的正當性。尤其入夜後過量使用藍光，不僅容易影響身體健康和破壞生態環境。藍光往往會擾亂晝夜節律，增加罹患癌症的風險，抑制褪黑激素的產生，損害對光敏感的眼球細胞，造成夜空污染，並破壞藝術品。這些問題可以透過使用蠟燭和白熾燈泡等低色溫光源來解決。然而，蠟燭的閃爍問題和白熾燈泡的高功耗使它們不受歡迎。因此，燭光有機發光二極管 (OLED) 被設計為無藍光、無閃爍且更節能。
OLED元件通常透過乾式或濕式製程製作。儘管乾式製作可以提高元件表現，但它仍有規格大小的限制、材料浪費和製造成本高等問題。相比之下，濕式製作的特點是生產成本低、材料利用率高、能夠使用可撓性基板並使用卷對卷方法製造大面積元件。然而，透過濕式製作技術實現高效的燭光 OLED 具有挑戰性。
本論文的主要目的是開發一種結構簡單的高效燭光OLED。為了滿足這一需求，首先本論文研究了一系列新型主體材料，如：DB-01、DB-03 和 DB-13，以製造高效的黃色磷光 OLED。研究結果顯示，主體 DB-03 和黃色客體PO-01 的元件達到44.6 lm/W 的最大能量效率 (PEmax)，比常見主體 CBP 的元件高 59%。高效率可能歸因於 DB-03 的特性，例如合適的最高佔據分子軌道/最低未佔據分子軌道 (HOMO/LUMO)、高效的主客體能量轉移、高三重態能量和高電荷遷移率。
然後，利用所獲得的黃色 OLED 元件製造具有橙紅色 (Ir(2-phq)3)客體的高效燭光 OLED。研究結果顯示，在 100 cd/m2 下，10wt%的 Ir(2-phq)3客體元件的最大能量效率為 23.7 lm/W，色溫為 1,700 K。最後，依序研究了四種電子傳輸材料（TmPyPb、PO-T2T、3P-T2T 和 TPBi）和四種電洞傳輸材料（Spiro-2CBP、m-MTDATA、KK-14 和 NPD）以進一步提升元件效率。其中，含有電子傳輸層 PO-T2T 和電洞傳輸層 KK-14 的元件表現出最高效率，最大能量效率為 50 lm/W（即電流效率為 45 cd/A，外部量子效率為 20% )，最大亮度為 42,851 cd/m2，在 100 cd/m2 時色溫為 1,732K。此外，該元件表現出 1.36% 的褪黑激素抑制敏感度和視網膜最大允許可暴露極限56,857 秒（16 小時）。電子傳輸層PO-T2T 的高載子遷移率和高三重態能量以及電洞傳輸KK-14 的高三重態能量、低表面粗糙度和高透明性可歸因於優異的元件表現。其超高效率且人體友善的燭光 OLED 展示了濕式製程製作的高品質 OLED 在市場上的潛力。

Most commercial lighting luminaires are not justifying their usage due to the presence of blue emission that significantly affects human health and the ecosystem, especially since they are utilized excessively at night. Blue emission tends to disrupt the circadian rhythm, increase cancer risk, suppress melatonin generation, damage light-sensitive eye tissues, cause night sky pollution, and destroy artifacts. Such issues can be addressed via low color temperature lights such as candles and incandescent bulbs. However, the flicker of candles and high-power consumption of incandescent bulbs made them undesirable. Hence, candlelight organic light-emitting diodes (OLEDs) are designed as blue-emission-free, flicker-free and more energy-saving.
OLEDs are usually fabricated either through a dry process or a wet process. The dry process has shortages of limited scalability, material wasting and expensive fabrication cost, despite it can deliver a high-performance device. In contrast, the wet process is characterized by low production cost, high material utilization rate, and an ability to use flexible substrate and fabricate a large area device using a roll-to-roll method. However, it was challenging to realize a highly efficient candlelight OLED via the wet process technique.
In this thesis, the main objective was to develop a simple structured highly-efficient candlelight OLED. To accomplish the need, a series of novel host materials, namely DB-01, DB-03 and DB-13, was first investigated to fabricate a highly efficient yellow phosphorescent OLED. As a result, the device based on the host DB-03 and yellow dopant PO-01 displayed a maximum power efficacy (PEmax) of 44.6 lm/W, which was 59% higher than the control part CBP based device. The high performance may be attributed to the characteristics of DB-03, such as suitable highest occupied molecular orbital/ lowest unoccupied molecular orbital (HOMO/LUMO), efficient host-guest energy transfer, high triplet energy, and high charge mobility.
Then, the obtained yellow OLED device was utilized to fabricate an efficient candlelight OLED with the incorporation of an orange-red (Ir(2-phq)3) emitter. As a result, a 10wt% Ir(2-phq)3 doped device exhibited a PEmax of 23.7 lm/W and a color temperature of 1,700 K at 100 cd/m2. Finally, four electron-transporting materials (TmPyPb, PO-T2T, 3P-T2T, and TPBi) and four hole-transporting materials (Spiro-2CBP, m-MTDATA, KK-14, and NPD) were sequentially investigated to optimize the device efficiency further. Amongst, the device based on electron transporting layer PO-T2T and hole transporting layer KK-14 showed the best performance with a PEmax of 50 lm/W (i.e., the current efficacy of 45 cd/A and the external quantum efficiency of 20%), a maximum luminance of 42,851 cd/m2 and a color temperature of 1,732 at 100 cd/m2. Furthermore, the device exhibits a 1.36% melatonin suppression sensitivity and a maximum permissible exposure limit of 56,857 s (16 hours) at 100 lx. The excellent device performance may be attributed to the high mobility and triplet energy of ETL PO-T2T and high triplet energy, low film roughness and high transparency of HTL KK-14. The demonstrated high-efficient and human-friendly candlelight OLED shows the potential to apply a solution-processable high-quality OLED on the market.

Table of Contents
Chinese Abstract……………………………………………………………………………….ii
English Abstract………………………………………………………………………………iv
Acknowledgement……………………………………………………………………………vi
Table of Contents……………………………………………………………………………..ix
Figure Captions………………………………………………………………………….…..xiii
Table Captions………………………………………………………………………….……xx
Abbreviations……………………………………………………………………………….xxii
Chapter 1. Introduction and Motivation……………………………………………..…1
Chapter 2. Fundamentals of Organic Light-emitting Diodes (OLEDs)
2.1. History and Development………………………………………………….……..5
2.2. Device Structure and Operational Mechanism………………………….…….....10
2.3. Functional Layers…………………………………………………….…………14
2.3.1 Electrodes……………………………………………………….……..14
2.3.2 Hole Injection/Transporting Layer (HIL/HTL)…………………..……16
2.3.3 Emissive Layer (EML)………………………………………..……….16
2.3.4 Electron Injection/Transporting Layer (EIL/ETL)………..…………...17
2.4. Key Parameters………………………………………………..………………...18
2.4.1 Turn-on Voltage (Von)…………………………..……………………..18
2.4.2 Power Efficacy (PE)………………………..………………………….18
2.4.3 Current Efficacy (CE)……………………….……………………..…..19
2.4.4 External Quantum Efficiency (EQE)……….…………………..……...19
2.4.5 Luminance………………………………………………...……………20
2.4.6 Correlated Color Temperature (CT)………………...………………….20
2.4.7 CIE color coordinates…………………………...……………………...22
2.4.8 Color rendering index (CRI)………………………...……………….…23
2.4.9 Spectrum Resemblance Index (SRI)…………………...………….……23
2.5. Fabrication Methods……………………………………….…..……….....……..25
2.5.1 Dry Process …………………………………………………………….25
2.5.2 Solution Process……………………………………...…………….…..26
Chapter 3. Literature Review of Candlelight OLEDs …………………………….…..28
Chapter 4. Experimental and Methodology …………………………………………...36
4.1. Materials Selection………………..…………………………………….……….36
4.1.1 Anode and Cathode……..………………………………………….…..36
4.1.2 HIL, HTL, EIL and ETL Materials………………………..…….……..36
4.1.3 Hosts…………………………………………………….………..…….37
4.1.4 Emitters……………………………………………………….…….….37
4.2. Theoretical Calculations……………………………………………….….……..47
4.2.1 Density Functional Theory (DFT)………………………………..….…47
4.2.2 Maximum Permissible Exposure-limit (MPE)………………….….…..47
4.2.3 Melatonin Suppression Sensitivity (MSS)……………….……….……48
4.3. Methodology…………………………………………….………………………49
4.3.1 Photophysical Characteristics………………………………….………49
4.3.2 Electrochemical Characteristics………….………………….…………49
4.3.3 Thermal Characteristics………………………………..………………50
4.3.4 Atomic Force Microscopy (AFM analysis)……..……………………..50
4.4. Device Fabrication and Measurements……………..……………………….…..52
4.4.1 Substrate Cleaning…………………..…………………………….…...52
4.4.2 Solution Preparation…………...……………………………………….53
4.4.3 Spin Coating………………………………………………………...….53
4.4.4 Thermal Deposition…………………………………………………….54
4.4.5 Device Measurement…………………………………………….…..…54
Chapter 5. Results and Discussion………………………………………………………55
5.1. Novel Hosts Enabling high-efficiency Solution-processed Yellow Organic Light-emitting Diodes…………………………………..…………………..….55
5.1.1 Device fabrication………………………………………….……….….56
5.1.2 Material Characteristics…………………………….………………….57
5.1.2.1. DFT……………………………….………………………….57
5.1.2.2. Photophysical……………………………….………………..61
5.1.2.3. Electrochemical…………………………………..…………..64
5.1.2.4. Thermal……………………………………………..………..67
5.1.2.5. Surface Morphology…………………………………...……..70
5.1.2.6. Charge Transporting……………………………………..…...72
5.1.2.6.1. Hole-only Devices (HOD)………….……..… 72
5.1.2.6.2. Electron-only Devices (EOD)………..…….…74
5.1.3 Electroluminescent Characteristics of Yellow OLEDs……………...…76
5.2. Highly-efficient Candlelight Organic Light-emitting Diode with a Very Low Color Temperature…………………………………………..…………….…..84
5.2.1 Device fabrication………………………………………………….…..84
5.2.2 Electroluminescent Characteristics of Candlelight OLEDs…………....85
5.3. Solution-processed Candlelight Organic Light-emitting Diodes with Different Electron-transporting Materials………………………………………………89
5.3.1 Device fabrication………………………………………………...……89
5.3.2 Materials and Charge Transporting Characteristics……………………90
5.3.2.1. Photophysical………………………………………...………90
5.3.2.2. Charge Transporting………………………………………….91
5.3.3 Electroluminescent Characteristics of Candlelight OLEDs……………94
5.4. Solution-processed Candlelight Organic Light-emitting Diodes with Different Hole-transporting Materials…………………………………………………..97
5.4.1 Device fabrication……………………………………………………...97
5.4.2 Material and Charge Transport Characteristics………………………..99
5.4.2.1. Surface Morphology ………………………………………...99
5.4.2.2. Photophysical Properties……………………………………100
5.4.2.3. Charge Transporting……………………………………...…103
5.4.3 Electroluminescent Characteristics of Candlelight OLEDs…………..105
Chapter 6. Conclusions……………………………………………………………...…110
References………………………………………………………………………………….113
Curriculum Vitae of the Author………………………………………………………….138
Appendix…………………………………………………………………………...………144

References
[1] H. Jou J, H. Yu H, C. Tung F, H. Chiang C, K. He Z and K. Wei M 2016 A replacement for incandescent bulbs: high-efficiency blue-hazard free organic light-emitting diodes J. Mater. Chem. C 5 176–82
[2] Jou J H, Su Y T, Liu S H, He Z K, Sahoo S, Yu H H, Chen S Z, Wang C W and Lee J R 2016 Wet-process feasible candlelight OLED J. Mater. Chem. C 4 6070–7
[3] Anon Do “environmentally friendly” LED lights cause BLINDNESS? | Daily Mail Online
[4] Jou J H, Su Y T, Liu S H, He Z K, Sahoo S, Yu H H, Chen S Z, Wang C W and Lee J R 2016 Wet-process feasible candlelight OLED J. Mater. Chem. C 4 6070–7
[5] Pauley S M 2004 Lighting for the human circadian clock: recent research indicates that lighting has become a public health issue Med. Hypotheses 63 588–96
[6] Mills P R, Tomkins S C and Schlangen L J M 2007 The effect of high correlated colour temperature office lighting on employee wellbeing and work performance J. Circadian Rhythms 5
[7] Sato M, Sakaguchi T and Morita T 2006 The effects of exposure in the morning to light of different color temperatures on the behavior of core temperature and melatonin secretion in humans http://dx.doi.org/10.1080/09291010500079734 36 287–92
[8] Anon The effects of exposure in the morning to light of different color temperatures on the behavior of core temperature and melatonin secretion in humans: Biological Rhythm Research: Vol 36, No 4
[9] Arendt J 2000 Melatonin, circadian rhythms, and sleep N. Engl. J. Med. 343 1114–6
[10] Anon Melatonin, Circadian Rhythms, and Sleep | NEJM
[11] Kloog I, Haim A, Stevens R G, Barchana M and Portnov B A 2008 Light at night co-distributes with incident breast but not lung cancer in the female population of Israel Chronobiol. Int. 25 65–81
[12] Bauer S E, Wagner S E, Burch J, Bayakly R and Vena J E 2013 A case-referent study: Light at night and breast cancer risk in Georgia Int. J. Health Geogr. 12
[13] Kloog I, Stevens R G, Haim A and Portnov B A 2010 Nighttime light level co-distributes with breast cancer incidence worldwide Cancer Causes Control 21 2059–68
[14] Urbano T, Vinceti M, Wise L A and Filippini T 2021 Light at night and risk of breast cancer: a systematic review and dose–response meta-analysis Int. J. Health Geogr. 20
[15] Johns L E, Jones M E, Schoemaker M J, McFadden E, Ashworth A and Swerdlow A J 2018 Domestic light at night and breast cancer risk: a prospective analysis of 105 000 UK women in the Generations Study Br. J. Cancer 118 600
[16] Stevens R G, George ;, Brainard C, David ;, Blask E, Lockley S W and Motta M E 2014 Breast cancer and circadian disruption from electric lighting in the modern world CA. Cancer J. Clin. 64 207–18
[17] Davis S, Mirick D K and Stevens R G 2001 Night Shift Work, Light at Night, and Risk of Breast Cancer JNCI J. Natl. Cancer Inst. 93 1557–62
[18] Anon Light Pollution Effects on Wildlife and Ecosystems - International Dark-Sky Association
[19] Jiang J, He Y, Kou H, Ju Z, Gao X and Zhao H 2020 The effects of artificial light at night on Eurasian tree sparrow (Passer montanus): Behavioral rhythm disruption, melatonin suppression and intestinal microbiota alterations Ecol. Indic. 108
[20] Chepesiuk R 2009 Missing the dark: Health effects of light pollution Environ. Health Perspect. 117
[21] Anon Dark-Sky says boo to blue light | LEDs Magazine
[22] Kido J, Kimura M and Nagai K 1995 Multilayer White Light-Emitting Organic Electroluminescent Device Science (80-. ). 267 1332–4
[23] Anon Philadelphia Museum of Art - Research : Conservation
[24] Jou J H, Chen P W, Chen Y L, Jou Y C, Tseng J R, Wu R Z, Hsieh C Y, Hsieh Y C, Joers P, Chen S H, Wang Y S, Tung F C, Chen C C and Wang C C 2013 OLEDs with chromaticity tunable between dusk-hue and candle-light Org. Electron. 14 47–54
[25] Jou J H, Wang H C, Shen S M, Peng S H, Wu M H, Chen S H and Wu P H 2012 Highly efficient color-temperature tunable organic light-emitting diodes J. Mater. Chem. 22 8117–20
[26] Jou J H, Chou K Y, Yang F C, Agrawal A, Chen S Z, Tseng J R, Lin C C, Chen P W, Wong K T and Chi Y 2014 A universal, easy-to-apply light-quality index based on natural light spectrum resemblance Appl. Phys. Lett. 104 203304
[27] Jou J-H, Hsieh C-Y, Chen P-W, Kumar S and Hong J H 2014 Candlelight style organic light-emitting diode: a plausibly human-friendly safe night light https://doi.org/10.1117/1.JPE.4.043598 4 043598
[28] Jou J H, Hsieh C Y, Tseng J R, Peng S H, Jou Y C, Hong J H, Shen S M, Tang M C, Chen P C and Lin C H 2013 Candle Light-Style Organic Light-Emitting Diodes Adv. Funct. Mater. 23 2750–7
[29] Thejo Kalyani N and Dhoble S J 2015 Novel materials for fabrication and encapsulation of OLEDs Renew. Sustain. Energy Rev. 44 319–47
[30] Kulkarni A P, Tonzola C J, Babel A and Jenekhe S A 2004 Electron transport materials for organic light-emitting diodes Chem. Mater. 16 4556–73
[31] Lee J, Chopra N, Eom S H, Zheng Y, Xue J, So F and Shi J 2008 Effects of triplet energies and transporting properties of carrier transporting materials on blue phosphorescent organic light emitting devices Appl. Phys. Lett. 93 123306
[32] Wang D, Wu Y, Bi R, Zhang H and Zhao D 2015 Solution-processed sodium hydroxide as the electron injection layer in inverted bottom-emission organic light-emitting diodes J. Mater. Chem. C 3 3922–7
[33] Sasabe H, Sato R, Suzuki K, Watanabe Y, Adachi C, Kaji H and Kido J 2018 Ultrahigh Power Efficiency Thermally Activated Delayed Fluorescent OLEDs by the Strategic Use of Electron-Transport Materials Adv. Opt. Mater. 6 1800376
[34] Kuik M, Wetzelaer G-J A H, Nicolai H T, Craciun N I, De Leeuw D M, Blom P W M, Craciun N I, De Leeuw D M, Blom W M, Kuik M, Wetzelaer G-J A H and Nicolai H T 2014 25th Anniversary Article: Charge Transport and Recombination in Polymer Light-Emitting Diodes Adv. Mater. 26 512–31
[35] Wang Y, Li B, Jiang C, Fang Y, Bai P and Wang Y 2021 Study on Electron Transport Characterization in TPBi Thin Films and OLED Application J. Phys. Chem. C 125 16753–8
[36] Shahnawaz, Siddiqui I, Nagar M R, Choudhury A, Lin J T, Blazevicius D, Krucaite G, Grigalevicius S and Jou J H 2021 Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature Mol. 2021, Vol. 26, Page 7558 26 7558
[37] Hwang J, Lee C, Jeong J E, Kim C Y, Woo H Y, Park S, Cho M J and Choi D H 2020 Rational Design of Carbazole- And Carboline-Based Polymeric Host Materials for Realizing High-Efficiency Solution-Processed Thermally Activated Delayed Fluorescence Organic Light-Emitting Diode ACS Appl. Mater. Interfaces 12 8485–94
[38] Shahnawaz S, Sudheendran Swayamprabha S, Nagar M R, Yadav R A K, Gull S, Dubey D K and Jou J H 2019 Hole-transporting materials for organic light-emitting diodes: an overview J. Mater. Chem. C 7 7144–58
[39] Jou J H, Kumar S, Agrawal A, Li T H and Sahoo S 2015 Approaches for fabricating high efficiency organic light emitting diodes J. Mater. Chem. C 3 2974–3002
[40] Jou J H, Chen S H, Shen S M, Jou Y C, Lin C H, Peng S H, Hsia S P, Wang C W, Chen C C and Wang C C 2011 High efficiency low color-temperature organic light-emitting diodes with a blend interlayer J. Mater. Chem. 21 17850–4
[41] Jou J H, Li T H, Kumar S, An C C, Agrawal A, Chen S Z, Fang P H, Krucaite G, Grigalevicius S, Grazulevicius J and Sung C F 2015 Enabling high-efficiency organic light-emitting diodes with a cross-linkable electron confining hole transporting material Org. Electron. 24 254–62
[42] Sudheendran Swayamprabha S, Dubey D K, Shahnawaz, Yadav R A K, Nagar M R, Sharma A, Tung F C and Jou J H 2021 Approaches for Long Lifetime Organic Light Emitting Diodes Adv. Sci. 8 2002254
[43] Wang J, Li Y, Chen L, Deng Y, Peng Y, Lu F and Zhu W 2020 High-performance hybrid white organic light-emitting diodes with bipolar host material and thermally activated delayed fluorescent emitter Opt. Mater. (Amst). 100 109673
[44] Adachi C, Baldo M A, Thompson M E and Forrest S R 2001 Nearly 100% internal phosphorescence efficiency in an organic light-emitting device J. Appl. Phys. 90 5048
[45] Holder E, Langeveld B M W and Schubert U S 2005 New Trends in the Use of Transition Metal–Ligand Complexes for Applications in Electroluminescent Devices Adv. Mater. 17 1109–21
[46] Tao Y, Wang Q, Yang C, Wang Q, Zhang Z, Zou T, Qin J, Ma D, Tao Y, Yang C, Zou T, Qin J, Wang Q, Zhang Z and Ma D 2008 A Simple Carbazole/Oxadiazole Hybrid Molecule: An Excellent Bipolar Host for Green and Red Phosphorescent OLEDs Angew. Chemie Int. Ed. 47 8104–7
[47] Avilov I, Marsal P, Brédas J L and Beljonne D 2004 Quantum-chemical design of host materials for full-color triplet emission Adv. Mater. 16 1624–9
[48] Adachi C, Kwong R C and Djurovich P 2001 Cite as Appl. Phys. Lett 79 2082
[49] Ulbricht C, Beyer B, Friebe C, Winter A and Schubert U S 2009 Recent Developments in the Application of Phosphorescent Iridium(III) Complex Systems Adv. Mater. 21 4418–41
[50] Hughes G and Bryce M R 2005 Electron-transporting materials for organic electroluminescent and electrophosphorescent devices J. Mater. Chem. 15 94–107
[51] Kim J-H and Park J-W 2017 Designing an electron-transport layer for highly efficient, reliable, and solution-processed organic light-emitting diodes J. Mater. Chem. C 5 3097–106
[52] Wang X, Shi C, Guo Q, Chen J, Qiao X, Ma D, Ahamad T, Alshehri S M and Bae S S 2017 Highly efficient charge generation and electron injection of m-MTDATA/m-MTDATA:HAT-CN/HAT-CN organic heterojunction on ITO cathode for high efficiency inverted white organic light-emitting diodes J. Appl. Phys. 122
[53] Nagar M R, Shahnawaz, Yadav R A K, Lin J T and Jou J H 2020 Nanocomposite Electron-Transport Layer Incorporated Highly Efficient OLED ACS Appl. Electron. Mater. 2 1545–53
[54] Löser F 2012 Improvement of device efficiency in PIN-OLEDs by controlling the charge carrier balance and intrinsic outcoupling methods J. Photonics Energy 2 021207
[55] Nagar M R, Shahnawaz, Yadav R A K, Lin J T and Jou J H 2020 Nanocomposite Electron-Transport Layer Incorporated Highly Efficient OLED ACS Appl. Electron. Mater. 2 1545–53
[56] Bernanose A, Comte M and Vouaux P 1953 Sur un nouveau mode d’émission lumineuse chez certains composés organiques J. Chim. Phys. 50 64–8
[57] Bernanose A and Vouaux P 1953 Électroluminescence organique : étude du mode d’émission J. Chim. Phys. 50 261
[58] Bernanose A, Comte M and Vouaux P 1953 Sur un nouveau mode d’émission lumineuse chez certains composés organiques J. Chim. Phys. 50 64
[59] Bernanose A, Comte M and Vouaux P 1954 Stabilisation de la phosphorescence des adsorbats organiques fluorescents J. Chim. Phys. 51 400–1
[60] Sano M, Pope M and Kallmann H 2004 Electroluminescence and Band Gap in Anthracene J. Chem. Phys. 43 2920
[61] Pope M, Kallmann H P and Magnante P 2004 Electroluminescence in Organic Crystals J. Chem. Phys. 38 2042
[62] Kaji H, Suzuki H, Fukushima T, Shizu K, Suzuki K, Kubo S, Komino T, Oiwa H, Suzuki F, Wakamiya A, Murata Y and Adachi C 2015 Purely organic electroluminescent material realizing 100% conversion from electricity to light Nat. Commun. 2015 61 6 1–8
[63] Thielemans R, bvba S and Vlaanderen O 2015 LED Display Applications and Design Considerations Handb. Vis. Disp. Technol. 1–10
[64] Krames M R 2012 Light Emitting Diodes: Fundamentals Handb. Vis. Disp. Technol. 1155–67
[65] Tang C W and Vanslyke S A 1998 Organic electroluminescent diodes Appl. Phys. Lett. 51 913
[66] Tang C W, Vanslyke S A and Chen C H 1998 Electroluminescence of doped organic thin films J. Appl. Phys. 65 3610
[67] Friend R H, Gymer R W, Holmes A B, Burroughes J H, Marks R N, Taliani C, Bradley D D C, Dos Santos D A, Brédas J L, Lögdlund M and Salaneck W R 1999 Electroluminescence in conjugated polymers Nat. 1999 3976715 397 121–8
[68] Koden M 2016 OLED Display and Lighting OLED Disp. Light. 1–222
[69] Zou S J, Shen Y, Xie F M, Chen J De, Li Y Q and Tang J X 2020 Recent advances in organic light-emitting diodes: toward smart lighting and displays Mater. Chem. Front. 4 788–820
[70] Liu B, Nie H, Lin G, Hu S, Gao D, Zou J, Xu M, Wang L, Zhao Z, Ning H, Peng J, Cao Y and Tang B Z 2017 High-performance doping-free hybrid white OLEDs based on blue aggregation-induced emission luminogens ACS Appl. Mater. Interfaces 9 34162–71
[71] Ashok Kumar S, Shankar J S, K Periyasamy B and Nayak S K 2019 Device engineering aspects of Organic Light-Emitting Diodes (OLEDs) https://doi.org/10.1080/25740881.2018.1563133 58 1597–624
[72] Sasabe H and Kido J 2013 Development of high performance OLEDs for general lighting J. Mater. Chem. C 1 1699–707
[73] Kuei C-Y, Tsai W-L, Tong B, Jiao M, Lee W-K, Chi Y, Wu C-C, Liu S-H, Lee G-H, Chou P-T, Kuei C, Tong B, Chi Y, Tsai W, Jiao M, Lee W, Wu C, Liu S, Lee G and Chou P 2016 Bis-Tridentate Ir(III) Complexes with Nearly Unitary RGB Phosphorescence and Organic Light-Emitting Diodes with External Quantum Efficiency Exceeding 31% Adv. Mater. 28 2795–800
[74] Lee J, Chen H F, Batagoda T, Coburn C, Djurovich P I, Thompson M E and Forrest S R 2015 Deep blue phosphorescent organic light-emitting diodes with very high brightness and efficiency Nat. Mater. 2015 151 15 92–8
[75] Kim M, Kyu Jeon S, Hwang S-H, Yeob Lee J, Kim M, Hwang S, Jeon S K and Lee J Y 2015 Stable Blue Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes with Three Times Longer Lifetime than Phosphorescent Organic Light-Emitting Diodes Adv. Mater. 27 2515–20
[76] Jou J H, Wang C P, Wu M H, Lin H W, Pan H C and Liu B H 2010 High-efficiency flexible white organic light-emitting diodes J. Mater. Chem. 20 6626–9
[77] Xu R P, Li Y Q and Tang J X 2016 Recent advances in flexible organic light-emitting diodes J. Mater. Chem. C 4 9116–42
[78] Hamer J W, Yamamoto A, Rajeswaran G and Slyke S A Van 2005 69.4: Invited Paper: Mass Production of Full-Color AMOLED Displays SID Symp. Dig. Tech. Pap. 36 1902–7
[79] Anon LG SIGNATURE Z9 88-inch OLED 4K Smart TV w/AI ThinQ® | LG USA
[80] Anon Apple: OLED company spotlight | OLED-Info
[81] Anon The iPhone 13 Pro Max’s record-setting OLED display is the brightest smartphone display on the market according to DisplayMate’s review - NotebookCheck.net News
[82] Anon LG to finally launch its transparent OLED signage displays | OLED-Info
[83] Anon Tanvas demonstrates a haptic-enabled flexible AMOLED display | OLED-Info
[84] Anon LG Display to Construct 5th Generation OLED Manufacturing Plant in South Korea - LEDinside
[85] Anon Luminescence Technology Corp.| OLED lighting
[86] Anon LG Display to Mass Produce OLED Light Panels That Last for 30,000 Hours - LEDinside
[87] Anon Plastic and flexible OLED displays market to reach $18bn by 2020 | IDTechEx Research Article
[88] Anon NTHU starts producing candlelight OLED lighting desk lamps | OLED-Info
[89] Anon On-Demand OLEDs in Any Shape and Size: Inuru Announces New Pilot Line - OLED Light
[90] Anon OLED Lighting Market Report | Global Forecast To 2028
[91] Jou J H, Wu M H, Shen S M, Wang H C, Chen S Z, Chen S H, Lin C R and Hsieh Y L 2009 Sunlight-style color-temperature tunable organic light-emitting diode Appl. Phys. Lett. 95 013307
[92] Jou J-H, Shen S-M, Wu M-H, Peng S H, Wang H-C and Peng H 2011 Sunlight-style organic light-emitting diodes https://doi.org/10.1117/1.3583640 1 011021
[93] Yuan J, Liu W, Yao J, Sun Q, Dai Y, Chen J, Yang D, Qiao X and Ma D 2020 Highly efficient charge generation and injection in HAT-CN/TAPC heterojunction for high efficiency tandem organic light-emitting diodes Org. Electron. 83 105745
[94] Xiao J, Wang X X, Zhu H, Gao X, Yang Z H, Zhang X H and Wang S D 2012 Efficiency enhancement utilizing hybrid charge generation layer in tandem organic light-emitting diodes Appl. Phys. Lett. 101 013301
[95] Chen Y, Wang Q, Chen J, Ma D, Yan D and Wang L 2012 Organic semiconductor heterojunction as charge generation layer in tandem organic light-emitting diodes for high power efficiency Org. Electron. 13 1121–8
[96] Jeong J A, Shin H S, Choi K H and Kim H K 2010 Flexible Al-doped ZnO films grown on PET substrates using linear facing target sputtering for flexible OLEDs J. Phys. D. Appl. Phys. 43 465403
[97] Kim J J, Han M K and Noh Y Y 2011 Flexible OLEDs and organic electronics Semicond. Sci. Technol. 26 030301
[98] Bai S, Zhang P and Beratan D N 2020 Predicting Dexter Energy Transfer Interactions from Molecular Orbital Overlaps J. Phys. Chem. C 124 18956–60
[99] Jin T, Uhlikova N, Xu Z, Zhu Y, Huang Y, Egap E and Lian T 2020 Competition of Dexter, Förster, and charge transfer pathways for quantum dot sensitized triplet generation J. Chem. Phys. 152 214702
[100] Skourtis S S, Liu C, Antoniou P, Virshup A M and Beratan D N 2016 Dexter Energy transfer pathways Proc. Natl. Acad. Sci. U. S. A. 113 8115–20
[101] Bai S, Zhang P, Antoniou P, Skourtis S S and Beratan D N 2019 Quantum interferences among Dexter energy transfer pathways Faraday Discuss. 216 301–18
[102] Anon Phys. Rev. Lett. 92, 218301 (2004) - Multichromophoric F\"orster Resonance Energy Transfer
[103] Kang M G and Guo L J 2007 Nanoimprinted Semitransparent Metal Electrodes and Their Application in Organic Light-Emitting Diodes Adv. Mater. 19 1391–6
[104] Anon Indium Tin Oxide Alternatives—High Work Function Transparent Conducting Oxides as Anodes for Organic Light‐Emitting Diodes
[105] Marks T J, Veinot J G C, Cui J, Yan H, Wang A, Edleman N L, Ni J, Huang Q, Lee P and Armstrong N R 2002 Progress in high work function TCO OLED anode alternatives and OLED nanopixelation Synth. Met. 127 29–35
[106] Phillips J M, Cava R J, Thomas G A, Carter S A, Kwo J, Siegrist T, Krajewski J J, Marshall J H, Peck W F and Rapkine D H 1994 Zinc-indium-oxide: A high conductivity transparent conducting oxide Appl. Phys. Lett. 67 2246
[107] Wang A, Dai J, Cheng J, Chudzik M P, Marks T J, Chang R P H and Kannewurf C R 1998 Charge transport, optical transparency, microstructure, and processing relationships in transparent conductive indium-zinc oxide films grown by low-pressure metal-organic chemical vapor deposition Appl. Phys. Lett. 73 327–9
[108] Freeman A J, Poeppelmeier K R, Mason T O, Chang R P H and Marks T J 2000 Chemical and Thin-Film Strategies for New Transparent Conducting Oxides MRS Bull. 25 45–51
[109] Kim K S, Zhao Y, Jang H, Lee S Y, Kim J M, Kim K S, Ahn J H, Kim P, Choi J Y and Hong B H 2009 Large-scale pattern growth of graphene films for stretchable transparent electrodes Nat. 2009 4577230 457 706–10
[110] Han T H, Lee Y, Choi M R, Woo S H, Bae S H, Hong B H, Ahn J H and Lee T W 2012 Extremely efficient flexible organic light-emitting diodes with modified graphene anode Nat. Photonics 2011 62 6 105–10
[111] Bae S, Kim H, Lee Y, Xu X, Park J S, Zheng Y, Balakrishnan J, Lei T, Ri Kim H, Song Y Il, Kim Y J, Kim K S, Özyilmaz B, Ahn J H, Hong B H and Iijima S 2010 Roll-to-roll production of 30-inch graphene films for transparent electrodes Nat. Nanotechnol. 2010 58 5 574–8
[112] Hecht D S, Hu L and Irvin G 2011 Emerging Transparent Electrodes Based on Thin Films of Carbon Nanotubes, Graphene, and Metallic Nanostructures Adv. Mater. 23 1482–513
[113] Tang J, Cao Q, Tulevski G, Jenkins K A, Nela L, Farmer D B and Han S J 2018 Flexible CMOS integrated circuits based on carbon nanotubes with sub-10 ns stage delays Nat. Electron. 2018 13 1 191–6
[114] Xu H, Liu P, Huang B, Jiang X, Gao Q and Liu L 2021 Preparation of Double-Layer Crossed Silver Nanowire Film and Its Application to OLED Coatings 2022, Vol. 12, Page 26 12 26
[115] Selzer F, Weiß N, Kneppe D, Bormann L, Sachse C, Gaponik N, Eychmüller A, Leo K and Müller-Meskamp L 2015 A spray-coating process for highly conductive silver nanowire networks as the transparent top-electrode for small molecule organic photovoltaics Nanoscale 7 2777–83
[116] Lee D J, Oh Y, Hong J M, Park Y W and Ju B K 2018 Light sintering of ultra-smooth and robust silver nanowire networks embedded in poly(vinyl-butyral) for flexible OLED Sci. Reports 2018 81 8 1–9
[117] Lee H, Lee D, Ahn Y, Lee E W, Park L S and Lee Y 2014 Highly efficient and low voltage silver nanowire-based OLEDs employing a n-type hole injection layer Nanoscale 6 8565–70
[118] Song W G, Kwon H J, Park J, Yeo J, Kim M, Park S, Yun S, Kyung K U, Grigoropoulos C P, Kim S and Hong Y K 2016 High-Performance Flexible Multilayer MoS2 Transistors on Solution-Based Polyimide Substrates Adv. Funct. Mater. 26 2426–34
[119] Xu J, Wang S, Wang G J N, Zhu C, Luo S, Jin L, Gu X, Chen S, Feig V R, To J W F, Rondeau-Gagné S, Park J, Schroeder B C, Lu C, Oh J Y, Wang Y, Kim Y H, Yan H, Sinclair R, Zhou D, Xue G, Murmann B, Linder C, Cai W, Tok J B H, Chung J W and Bao Z 2017 Highly stretchable polymer semiconductor films through the nanoconfinement effect Science (80-. ). 355
[120] Oh J Y, Rondeau-Gagné S, Chiu Y C, Chortos A, Lissel F, Wang G J N, Schroeder B C, Kurosawa T, Lopez J, Katsumata T, Xu J, Zhu C, Gu X, Bae W G, Kim Y, Jin L, Chung J W, Tok J B H and Bao Z 2016 Intrinsically stretchable and healable semiconducting polymer for organic transistors Nat. 2016 5397629 539 411–5
[121] Naguib M, Mashtalir O, Carle J, Presser V, Lu J, Hultman L, Gogotsi Y and Barsoum M W 2012 Two-dimensional transition metal carbides ACS Nano 6 1322–31
[122] Cai Y, Shen J, Ge G, Zhang Y, Jin W, Huang W, Shao J, Yang J and Dong X 2018 Stretchable Ti3C2Tx MXene/Carbon Nanotube Composite Based Strain Sensor with Ultrahigh Sensitivity and Tunable Sensing Range ACS Nano 12 56–62
[123] Kim Y H, Sachse C, MacHala M L, May C, Müller-Meskamp L and Leo K 2011 Highly Conductive PEDOT:PSS Electrode with Optimized Solvent and Thermal Post-Treatment for ITO-Free Organic Solar Cells Adv. Funct. Mater. 21 1076–81
[124] Chan M Y, Lai S L and Fung M K 2004 Impact of the metal cathode and CsF buffer layer on the performance of organic light-emitting devices ARTICLES YOU MAY BE INTERESTED IN J. Appl. Phys. 95 5397
[125] Geffroy B, le Roy P and Prat C 2006 Organic light-emitting diode (OLED) technology: Materials, devices and display technologies Polym. Int. 55 572–82
[126] Tyan Y-S 2011 Organic light-emitting-diode lighting overview J. Photonics Energy 1 011009
[127] Han T H, Song W and Lee T W 2015 Elucidating the crucial role of hole injection layer in degradation of organic light-emitting diodes ACS Appl. Mater. Interfaces 7 3117–25
[128] Kumar K, Kesavan K K, Thakur D, Banik S, Jayakumar J, Cheng C H, Jou J H and Ghosh S 2021 Functional Pyrene-Pyridine-Integrated Hole-Transporting Materials for Solution-Processed OLEDs with Reduced Efficiency Roll-Off ACS Omega 6 10515–26
[129] Martins J S, Bartolomeu A A, Dos Santos W H, Da Silva Filho L C, De Oliveira E F, Lavarda F C, Cuin A, Legnani C, Maciel I O, Fragneaud B and Quirino W G 2017 New Class of Organic Hole-Transporting Materials Based on Xanthene Derivatives for Organic Electronic Applications J. Phys. Chem. C 121 12999–3007
[130] Kuwabara Y, Ogawa H, Inada H, Noma N and Shirota Y 1994 Thermally stable multilared organic electroluminescent devices using novel starburst molecules, 4,4′,4″‐Tri(N‐carbazolyl)triphenylamine (TCTA) and 4,4′,4″‐Tris(3‐methylphenylphenylamino)triphenylamine (m‐MTDATA), as hole‐transport materials Adv. Mater. 6 677–9
[131] Kumar S, An C C, Sahoo S, Griniene R, Volyniuk D, Grazulevicius J V., Grigalevicius S and Jou J H 2017 Solution-processable naphthalene and phenyl substituted carbazole core based hole transporting materials for efficient organic light-emitting diodes J. Mater. Chem. C 5 9854–64
[132] Dubey D K, Krucaite G, Swayamprabha S S, Yadav R A K, Blazevicius D, Tagare J, Chavhan S, Hsueh T C, Vaidyanathan S, Grigalevicius S and Jou J H 2020 Fluorene based amorphous hole transporting materials for solution processed organic light-emitting diodes Org. Electron. 79 105633
[133] Tsujimura T 2017 OLED Display Fundamentals and Applications OLED Disp. Fundam. Appl.
[134] Blochwitz J, Pfeiffer M, Fritz T and Leo K 1998 Low voltage organic light emitting diodes featuring doped phthalocyanine as hole transport material Appl. Phys. Lett. 73 729
[135] Cias P, Slugovc C and Gescheidt G 2011 Hole transport in triphenylamine based OLED devices: From theoretical modeling to properties prediction J. Phys. Chem. A 115 14519–25
[136] Sudyoadsuk T, Chasing P, Kaewpuang T, Manyum T, Chaiwai C, Namuangruk S and Promarak V 2020 High efficiency and low efficiency roll-off hole-transporting layer-free solution-processed fluorescent NIR-OLEDs based on oligothiophene–benzothiadiazole derivatives J. Mater. Chem. C 8 5045–50
[137] Tsai K-W, Hung M-K, Mao Y-H, Chen S-A, Tsai K-W, Hung M-K, Mao Y-H S and Chen -A 2019 Solution-Processed Thermally Activated Delayed Fluorescent OLED with High EQE as 31% Using High Triplet Energy Crosslinkable Hole Transport Materials Adv. Funct. Mater. 29 1901025
[138] Aonuma M, Oyamada T, Sasabe H, Miki T and Adachi C 2007 Material design of hole transport materials capable of thick-film formation in organic light emitting diodes Appl. Phys. Lett. 90 183503
[139] Huh D H, Kim G W, Kim G H, Kulshreshtha C and Kwon J H 2013 High hole mobility hole transport material for organic light-emitting devices Synth. Met. 180 79–84
[140] Ikai M, Tokito S, Sakamoto Y, Suzuki T and Taga Y 2001 Highly efficient phosphorescence from organic light-emitting devices with an exciton-block layer Appl. Phys. Lett. 79 156
[141] Yadav R A K, Dubey D K, Chen S Z, Liang T W and Jou J H 2020 Role of Molecular Orbital Energy Levels in OLED Performance Sci. Reports 2020 101 10 1–15
[142] Jou J H, Lin Y T, Su Y T, Song W C, Kumar S, Dubey D K, Shyue J J, Chang H Y, You Y W and Liang T W 2019 Plausible degradation mechanisms in organic light-emitting diodes Org. Electron. 67 222–31
[143] Lee J H, Shin H, Kim J M, Kim K H and Kim J J 2017 Exciplex-forming co-host-based red phosphorescent organic light-emitting diodes with long operational stability and high efficiency ACS Appl. Mater. Interfaces 9 3277–81
[144] Song W and Lee J Y 2017 Design strategy of exciplex host for extended operational lifetime Org. Electron. 48 285–90
[145] Lim H, Shin H, Kim K H, Yoo S J, Huh J S and Kim J J 2017 An Exciplex Host for Deep-Blue Phosphorescent Organic Light-Emitting Diodes ACS Appl. Mater. Interfaces 9 37883–7
[146] Ichikawa M, Kawaguchi T, Kobayashi K, Miki T, Obara T, Furukawa K, Koyama T and Taniguchi Y 2005 55.2: Bipyridyl Oxadiazoles as a New Class of Durable and Efficient Electron-Transporting Materials SID Symp. Dig. Tech. Pap. 36 1652–5
[147] Kanno H, Hamada Y, Nishimura K, Okumoto K, Saito N, Mameno K and Shibata K 2006 Reduction in power consumption for full-color active matrix organic light-emitting devices Japanese J. Appl. Physics, Part 2 Lett. 45 L947
[148] Kim J T, Lee J, Jang S, Yu Z, Park J H, Jung E D, Lee S, Song M H, Whang D R, Wu S, Park S H, Chang D W and Lee B R 2020 Solution processable small molecules as efficient electron transport layers in organic optoelectronic devices J. Mater. Chem. A 8 13501–8
[149] Sun K, Chu D, Cui Y, Tian W, Sun Y and Jiang W 2017 Near-infrared thermally activated delayed fluorescent dendrimers for the efficient non-doped solution-processed organic light-emitting diodes Org. Electron. 48 389–96
[150] Potera C 2000 The core of the candle problem Environ. Health Perspect. 108
[151] Reineke S, Lindner F, Schwartz G, Seidler N, Walzer K, Lüssem B and Leo K 2009 White organic light-emitting diodes with fluorescent tube efficiency Nat. 2009 4597244 459 234–8
[152] Adamovich V, Brooks J, Tamayo A, Alexander A M, Djurovich P I, D’Andrade B W, Adachi C, Forrest S R and Thompson M E 2002 High efficiency single dopant white electrophosphorescent light emitting diodes New J. Chem. 26 1171–8
[153] Fukagawa H, Watanabe K and Tokito S 2009 Efficient white organic light emitting diodes with solution processed and vacuum deposited emitting layers Org. Electron. 10 798–802
[154] Chien C H, Hsu F M, Shu C F and Chi Y 2009 Efficient red electrophosphorescence from a fluorene-based bipolar host material Org. Electron. 10 871–6
[155] Jou J H, Shen S M, Chen S H, Wu M H, Wang W Ben, Wang H C, Lin C R, Chou Y C, Wu P H and Shyue J J 2010 Highly efficient orange-red phosphorescent organic light-emitting diode using 2,7-bis(carbazo-9-yl)-9,9-ditolyfluorene as the host Appl. Phys. Lett. 96 143306
[156] Jou J H, Tang M C, Chen P C, Wang Y S, Shen S M, Chen B R, Lin C H, Wang W Ben, Chen S H, Chen C T, Tsai F Y, Wang C W, Chen C C and Wang C C 2012 Organic light-emitting diode-based plausibly physiologically-friendly low color-temperature night light Org. Electron. 13 1349–55
[157] Jou J H, Chen S H, Shen S M, Jou Y C, Lin C H, Peng S H, Hsia S P, Wang C W, Chen C C and Wang C C 2011 High efficiency low color-temperature organic light-emitting diodes with a blend interlayer J. Mater. Chem. 21 17850–4
[158] Gong Y, Liu J, Zhang Y, He G, Lu Y, Fan W Bin, Yuan W Z, Sun J Z and Zhang Y 2014 AIE-active, highly thermally and morphologically stable, mechanochromic and efficient solid emitters for low color temperature OLEDs J. Mater. Chem. C 2 7552–60
[159] Hu Y, Zhang T, Chen J, Ma D and Cheng C H 2014 Hybrid Organic Light-Emitting Diodes with Low Color-Temperature and High Efficiency for Physiologically-Friendly Night Illumination Isr. J. Chem. 54 979–85
[160] Singh M, Jou J H, Sahoo S, Sujith S, He Z K, Krucaite G, Grigalevicius S and Wang C W 2018 High light-quality OLEDs with a wet-processed single emissive layer Sci. Reports 2018 81 8 1–9
[161] Korshunov V M, Chmovzh T N, Knyazeva E A, Taydakov I V., Mikhalchenko L V., Varaksina E A, Saifutyarov R S, Avetissov I C and Rakitin O A 2019 A novel candle light-style OLED with a record low colour temperature Chem. Commun. 55 13354–7
[162] Sun Q, Hu Y, Dai Y and Ma D 2017 Low color-temperature, high color rendering index hybrid white organic light-emitting diodes by the effective control of exciton recombination zone J. Mater. Chem. C 5 8022–6
[163] Jou J H, Singh M, Su Y T, Liu S H and He Z K 2017 Blue-hazard-free Candlelight OLED J. Vis. Exp. 2017
[164] Jou J H, Singh M, Song W C and Liu S H 2017 Printable candlelight-style organic light-emitting diode IOP Conf. Ser. Mater. Sci. Eng. 215 012022
[165] Jou J-H, Hsieh C-Y, Tseng J-R, Peng S-H, Jou Y-C, Hong J H, Shen S-M, Tang M-C, Chen P-C and Lin C-H 2013 Candle Light-Style Organic Light-Emitting Diodes Adv. Funct. Mater. 23 2750–7
[166] Jou J H, Su Y T, Liu S H, He Z K, Sahoo S, Yu H H, Chen S Z, Wang C W and Lee J R 2016 Wet-process feasible candlelight OLED J. Mater. Chem. C 4 6070–7
[167] Lin Y-H, Yang W-Y, Lin Y-J, Chen S-Z, Wen S-W and Jou J-H 2021 Blue-hazard free candlelight-style tandem organic light-emitting diode Org. Electron. 98 106294
[168] Li C N, Kwong C Y, Djurišić A B, Lai P T, Chui P C, Chan W K and Liu S Y 2005 Improved performance of OLEDs with ITO surface treatments Thin Solid Films 477 57–62
[169] Lu D, Wu Y, Guo J, Lu G, Wang Y and Shen J 2003 Surface treatment of indium tin oxide by oxygen-plasma for organic light-emitting diodes Mater. Sci. Eng. B 97 141–4
[170] Benor A, Takizawa S ya, Pérez-Bolívar C and Anzenbacher P 2010 Efficiency improvement of fluorescent OLEDs by tuning the working function of PEDOT:PSS using UV–ozone exposure Org. Electron. 11 938–45
[171] Able K P and Able M A 1995 Manipulations of polarized skylight calibrate magnetic orientation in a migratory bird J. Comp. Physiol. A 1995 1773 177 351–6
[172] Jou J-H, Swayamprabha S S, Yadav R A K and Dubey D K 2018 Nano-Structures Enabling Sunlight and Candlelight-Style OLEDs J. Nanomater. Mol. Nanotechnol. 2018
[173] Pazini A, Maqueira L, Avila H C, Valente F M, Aderne R E, Back D, Aucélio R Q, Cremona M and Limberger J 2018 Phenoxy-benzothiadiazole dyes: Synthesis, photophysical properties and preliminary application in OLEDs Tetrahedron Lett. 59 2994–9
[174] Sun D, Ren Z and Yan S 2018 Efficient triplet utilization in conventional solution-processed phosphorescent organic light emitting diodes using a thermal activated delayed fluorescence polymer as an assistant host J. Mater. Chem. C 6 4800–6
[175] Yang T, Peng S, Barnett R, Wu D, Feng X and Oliffe J L 2018 Association between bedtime and self-reported illness among college students: a representative nationwide study of China Public Health 159 67–9
[176] Liu Y, Wei X, Li Z, Liu J, Wang R, Hu X, Wang P, Qi T and Wang Y 2018 Interface Exciplex Anchoring the Color Stability of Solution-Processed Thermally Activated Delayed Fluorescent White Organic Light-Emitting Diodes Adv. Opt. Mater. 6 1800978
[177] Ohisa S, Takahashi T, Igarashi M, Fukuda H, Hikichi T, Komatsu R, Ueki E, Pu Y-J, Chiba T, Kido J, Ohisa S, Takahashi T, Fukuda H, Hikichi T, Komatsu R, Pu Y, Chiba T, Kido J, Igarashi M and Ueki E 2019 An Indolocarbazole-Based Thermally Activated Delayed Fluorescence Host for Solution-Processed Phosphorescent Tandem Organic Light-Emitting Devices Exhibiting Extremely Small Efficiency Roll-Off Adv. Funct. Mater. 29 1808022
[178] Nakanotani H, Masui K, Nishide J, Shibata T and Adachi C 2013 Promising operational stability of high-efficiency organic light-emitting diodes based on thermally activated delayed fluorescence Sci. Reports 2013 31 3 1–6
[179] Tao Y, Yang C and Qin J 2011 Organic host materials for phosphorescent organic light-emitting diodes Chem. Soc. Rev. 40 2943–70
[180] Wang S, Yuan X, Dong Z, Li J and Shao T 2018 Characteristics of lactic acid bacteria isolated from different sources and their effects on the silage quality of oat (Avena sativa L.) straw on the Tibetan Plateau Grassl. Sci. 64 128–36
[181] Gong S, Chen Y, Yang C, Zhong C, Qin J and Ma D 2010 De Novo Design of Silicon-Bridged Molecule Towards a Bipolar Host: All-Phosphor White Organic Light-Emitting Devices Exhibiting High Efficiency and Low Efficiency Roll-Off Adv. Mater. 22 5370–3
[182] Ren B Y, Guo R Da, Zhong D K, Ou C J, Xiong G, Zhao X H, Sun Y G, Jurow M, Kang J, Zhao Y, Li S B, You L X, Wang L W, Liu Y and Huang W 2017 A Yellow-Emitting Homoleptic Iridium(III) Complex Constructed from a Multifunctional Spiro Ligand for Highly Efficient Phosphorescent Organic Light-Emitting Diodes Inorg. Chem. 56 8397–407
[183] Adachi C, Baldo M A, Thompson M E and Forrest S R 2001 Nearly 100% internal phosphorescence efficiency in an organic light emitting device J. Appl. Phys. 90 5048–51
[184] Tao Y, Wang Q, Yang C, Wang Q, Zhang Z, Zou T, Qin J and Ma D 2008 A Simple Carbazole/Oxadiazole Hybrid Molecule: An Excellent Bipolar Host for Green and Red Phosphorescent OLEDs Angew. Chemie Int. Ed. 47 8104–7
[185] Adachi C, Kwong R C, Djurovich P, Adamovich V, Baldo M A, Thompson M E and Forrest S R 2001 Endothermic energy transfer: A mechanism for generating very efficient high-energy phosphorescent emission in organic materials Appl. Phys. Lett. 79 2082–4
[186] Tsai M H, Hong Y H, Chang C H, Su H C, Wu C C, Matoliukstyte A, Simokaitiene J, Grigalevicius S, Grazulevicius J V. and Hsu C P 2007 3-(9-carbazolyI)carbazoles and 3,6-Di(9-carbazolyl)carbazoles as effective host materials for efficient blue organic electrophosphorescence Adv. Mater. 19 862–6
[187] Tao Y, Yang C and Qin J 2011 Organic host materials for phosphorescent organic light-emitting diodes Chem. Soc. Rev. 40 2943–70
[188] Baldo M A and Forrest S R 2000 Transient analysis of organic electrophosphorescence: I. Transient analysis of triplet energy transfer Phys. Rev. B 62 10958
[189] Zhang D, Cai M, Zhang Y, Zhang D and Duan L 2015 Highly Efficient Simplified Single-Emitting-Layer Hybrid WOLEDs with Low Roll-off and Good Color Stability through Enhanced Förster Energy Transfer ACS Appl. Mater. Interfaces 7 28693–700
[190] Zhao F, Wei Y, Xu H, Chen D, Ahamad T, Alshehri S, Pei Q and Ma D 2017 Spatial exciton allocation strategy with reduced energy loss for high-efficiency fluorescent/phosphorescent hybrid white organic light-emitting diodes Mater. Horizons 4 641–8
[191] Sasabe H and Kido J 2019 Low Molecular Weight Materials: Electron-Transport Materials Handb. Org. Light. Diodes 1–10
[192] Lee H, Ahn H and Lee C 2011 Device characteristics of blue phosphorescent organic light-emitting diodes depending on the electron transport materials http://dx.doi.org/10.1080/15980316.2011.621323 12 219–22
[193] Xu T, Zhang Y-X, Murtaza I and Meng H 2017 P-170: Organic Light-Emitting Diodes Incorporating a Novel Exciplex-Forming Host: A Synergistic Strategy to Design Highly Simplified OLEDs for Application SID Symp. Dig. Tech. Pap. 48 1915–8
[194] Anon TmPyPB, 1,3,5-Tris(3-pyridyl-3-phenyl)benzene | Sublimed, 921205-03-0 | Ossila
[195] Hung W Y, Fang G C, Lin S W, Cheng S H, Wong K T, Kuo T Y and Chou P T 2014 The first tandem, all-exciplex-based woled Sci. Rep. 4 1–11
[196] Jou J H, Kumar S, Singh M, Chen Y H, Chen C C and Lee M T 2015 Carrier modulation layer-enhanced organic light-emitting diodes Molecules 20 13005–30
[197] Anon 3P-T2T Phosphorescent Host Material and TADF Exciplex | Ossila
[198] Ying S, Xiao S, Yao J, Sun Q, Dai Y, Yang D, Qiao X, Chen J, Zhu T, Ma D, Ying S A, Xiao S, Yao J W, Sun Q, Dai Y F, Yang D Z, Qiao X F, Chen J S, Ma D G and Zhu T F 2019 High-Performance White Organic Light-Emitting Diodes with High Efficiency, Low Efficiency Roll-Off, and Superior Color Stability/Color Rendering Index by Strategic Design of Exciplex Hosts Adv. Opt. Mater. 7 1901291
[199] Liu X-K, Chen Z, Qing J, Zhang W-J, Wu B, Tam L, Zhu F, Zhang X-H, Lee C-S, Liu X-K, Qing J W, Zhang -J, Lee C-S, Chen Z X, Zhang -H, Wu B, Tam H L, Zhu F, Kong H and China P R X 2015 Remanagement of Singlet and Triplet Excitons in Single-Emissive-Layer Hybrid White Organic Light-Emitting Devices Using Thermally Activated Delayed Fluorescent Blue Exciplex Adv. Mater. 27 7079–85
[200] Jou J-H, Kumar S, Agrawal A, Li T-H and Sahoo S 2015 Approaches for fabricating high efficiency organic light emitting diodes J. Mater. Chem. C 3 2974–3002
[201] Anon NPB (NPD) OLED Material / Chemical | 123847-85-8 | Ossila
[202] Shahnawaz S, Sudheendran Swayamprabha S, Nagar M R, Yadav R A K, Gull S, Dubey D K and Jou J H 2019 Hole-transporting materials for organic light-emitting diodes: An overview J. Mater. Chem. C 7 7144–58