在現今全球對能源需求與日俱增的情勢下，發展替代能源為刻不容緩的議題。太陽能為目前公認為最乾淨並取之不盡的替代能源之一。我們致力於研究薄膜型太陽能技術以期未來能取代現有的發電技術與拓展太陽能應用領域。銅銦鎵硒(CIGS)太陽能電池因具有高吸收係數與直接能隙等物理特性，成為薄膜型太陽能電池界的領導者，也是目前薄膜型太陽能電池中最高效率的紀錄保持者。本論文主要的研究為一階段濺鍍法製備CIGS薄膜的製程開發與分析研究。
使用CIGS四元靶濺鍍法製備CIGS太陽能電池之製程是本實驗室極力發展的創新技術，可有效降低製程與材料成本，簡化製程複雜性，更可達到低污染、高效率之表現。然而，此新技術仍尚待完整的研究開發及進一步的深入探討。在本論文的第一部分，我們著重在建立濺鍍四元靶成長CIGS薄膜的成長機制。此部分主要探討CIGS與底電極鉬與CIGS的磊晶關係。在於無添加額外硒氣氛的一階段CIGS濺鍍法中，除了無副產物硒化鉬生成於CIGS與鉬電極介面，濺鍍法CIGS薄膜成長也將直接受影響於底襯鉬電極。針對鉬電極的研究發現下，發現可以使用應力製作出不同的鉬底襯織構，進一步控制CIGS的晶體優選方向。CIGS晶體的優選方向被視為改善晶體特性與影響雜質擴散的重要一環，在本章節，我們成功的利用底襯電極控制CIGS(112)及(220/204)兩種優選方向，並進一步探討鈉離子於不同優選方向CIGS內之擴散行為。
接著則是提出此濺鍍法技術所遭遇的瓶頸，並進一步利用系統化分析提出問題可能的機制。濺鍍法CIGS薄膜需克服在製作過程中硒逸散導致硒缺乏的材料缺陷問題。微量的硒缺乏變化將導致光電特性惡化，但針對硒缺乏所引起的成分空間分布不均及其響應一直缺乏決定性的檢測方法與技術。藉由高解析場發射電子微探儀搭配導電式原子力顯微術，我們從微區觀測中確立了濺鍍法中硒逸散所導致薄膜成分變化的機制，並連結到缺陷、晶界表現與光電特性的變化。其發展之分析技術也可應用於其他多元成分化合物之系統，提供未來結合材料科學與太陽能光電物理更多應用領域。
最後，我在製程當中添加鹼金屬鈉參與薄膜成長使之產生催化作用，直接抑制硒逸散的發生，解決薄膜硒缺乏的問題；進一步藉由共鍍鎵硒二元靶即時建構CIGS薄膜內的能帶工程，大幅增加濺鍍CIGS晶體的品質與提升元件表現。在本論文中，我們已成功將其與一段式濺鍍銅銦鎵硒薄膜製程整合，並加入奈米銀線取代傳統光窗層改善透光性與導電性，觀察到明顯元件表現之提升，完成效率高達14 %之元件表現。此外，並進一步整合此濺鍍法技術，並結合其他不同波段的薄膜太陽能電池成堆疊式太陽能電池，在機械式堆疊的設計下，最高效率可超過18 %

With increasing demand for energy, ramping up the technology on alternative energy resource has been a pressing issue. Solar energy is a practical, affordable solution to our electricity needs. We work toward developing the thin film solar cells technology to diversify our power supply and expand its application fields. Cu(In,Ga)Se2 (CIGS) has been the leading pioneer and the highest efficiency record holder in thin film solar cells due to its nature within high absorption coefficient and direct bandgap. In this dissertation, the developments on one-step sputtering techniques and characterizations were investigated.
The innovative technique of one-step sputtering process from a quaternary target is the key project in my group. The uniqueness of simple process, clean deposition environment, and high materials utilization reveals the potential for commercialization. However, further improvements need more involvements and developments. In the first part of this dissertation, the sputtered-CIGS growth mechanism and heteroepitaxy relationship between CIGS and Mo was investigated. Without the common observed interlayer MoSe2 between CIGS and Mo, the preferred orientation of CIGS can be directly controlled by Mo underlayer. Stress induces new Mo texture and further influences CIGS preferred orientation. The preferred orientation of CIGS has been reported to be one of the important factors to achieve high crystalline quality and impact impurity diffusion. By underlayer engineering, the diffusion capability of Na in (112) and (220/204)-preferred oriented CIGS was detectable.
A mechanism for possible Se loss route in the one-step sputtering process was proposed. Se deficiency induces the deterioration of optoelectronic properties and limits CIGS efficiency. However, the Se deficiency-induced non-uniformity on composition and its optoelectronic properties has rare decisive evidence to connect each other. By involving the field-emission electron probe microanalysis (FE-EPMA) and conductive atomic force microscope (C-AFM), the assumption of Se loss mechanism was verified. The defect formation and grain boundaries property deterioration due to the Se distribution were also confirmed, providing a new clue for a comprehensive analysis of multi-compound materials.
Finally, sputtered-CIGS absorbers with composition recovery performed particularly well due to the Na-precursor pre-deposition. Furthermore, the bandgap engineering by Ga-profile can be realized by the Ga2Se3/CIGS co-sputtering, leading to a vast improvement in cell performance. Most important of all, the Ag nanowires-based conductive transparent electrode as a window layer has successfully improved the transparency and conductivity, which results in over 14% of final device performance; therefore, over 18% efficiency by integrated perovskite/CIGS solar cells with a mechanical stacking methodology was also demonstrated.

中文摘要 I
ABSTRACT II
ACKNOWLEDGEMENT III
CONTENT IV
LIST OF FIGURES VII
LIST OF TABLES XI
CHAPTER 1 1
INTRODUCTION 1
1.1 ENERGY AND PHOTOVOLTAIC TECHNOLOGY 1
1.2 THEORETICAL BACKGROUND 3
1.3 MATERIALS SELECTION OF ABSORBER LAYERS 6
1.4 CIGS THIN FILMS SOLAR CELLS 8
1.5 OVERVIEW OF DISSERTATION 11
CHAPTER 2 12
LITERATURE REVIEW 12
2.1 THE OPERATION OF SOLAR CELLS 13
2.2 MATERIAL PROPERTIES OF CIGS SOLAR CELLS 16
2.1.1 Phase and structure of CIGS absorber 19
2.1.2 Composition deviation and electrical properties 23
2.1.3 Preferred orientation effect in CIGS 26
2.3 NA EFFECT IN CIGS 27
2.4 FABRICATION PROCESS OF CIGS ABSORBERS 30
2.4.1 Three-stage co-evaporation process 30
2.4.2 Two-step process: precursors with post-selenization 32
2.4.3 One-step sputtering process 33
CHAPTER 3 36
EXPERIMENTAL TECHNIQUES 36
3.1 SAMPLE PREPARATION 36
3.1.1 Sputtering deposition 36
3.1.2 Chemical bath deposition 37
3.1.3 Microanalysis sample- FIB system 37
3.2 CHARACTERIZATION METHODS 38
3.2.1 X-ray diffraction 38
3.2.2 Field emission electron probe microanalysis (FE-EPMA) 39
3.2.3 Transmission electron microscope (TEM) 40
3.2.4 X-ray photoelectron spectroscopy (XPS) 41
3.2.5 Photoluminescence (PL) and time-resolved PL (TR-PL) spectroscopy 42
3.2.6 Conductive AFM (C-AFM) 43
3.2.7 Current-voltage characterization (J-V) 43
3.2.8 Quantum efficiency response (EQE) 43
3.2.9 Capacitance-voltage measurement (C-V) 44
CHAPTER 4 45
CIGS GROWTH IN ONE-STEP SPUTTERING: PREFERRED ORIENTATION ENGINEERING AND NA MANIPULATION BY UNDERLAYER INTERFACE CONTROL 45
4.1 INTRODUCTION 46
4.2 EXPERIMENTAL DETAIL 48
4.3 RESULTS AND DISCUSSION 49
4.3.1 Characterization of (110) and (211)-preferred Mo back contacts 49
4.3.2 Orientation analysis of CIGS with different Mo under-layers 53
4.3.3 Na diffusion in preferred-oriented CIGS 61
4.4 SUMMARY 65
CHAPTER 5 66
THE CHALLENGE OF THE ONE-STEP CIGS SPUTTERING SYSTEM: SE-LOSS MECHANISM AND SE-DISTRIBUTION EFFECT 66
5.1 INTRODUCTION 67
5.2 EXPERIMENTAL DETAIL 69
5.3 RESULTS AND DISCUSSION 71
5.3.1 Characterization in sputtered CIGS films 71
5.3.2 Se-loss mechanism 76
5.3.3 Se-distribution effect 81
5. 4 SUMMARY 91
CHAPTER 6 92
THE SOLUTION OF SE DEFICIENCY AND DEVELOPMENTS FOR BOOSTING CELL PERFORMANCE IN ONE-STEP SPUTTERING PROCESS 92
6.1 INTRODUCTION 93
6.2 EXPERIMENTAL DETAIL 95
6.3 RESULTS AND DISCUSSION 97
6.3.1 NaF pre-deposition 97
6.3.2 In-situ band gap grading engineering by co-sputtering with Ga2Se3 target 112
6.3.3 Promising Ag nanowire-based transparent conductive electrodes (TCEs) 120
6.4 SUMMARY 124
CHAPTER 7 126
CONCLUSION AND PROSPECTS 126
7.1 CONCLUSION 126
7.2 SUGGESTION FOR FUTURE OUTLOOK 128
BIBLIOGRAPHY 131
APPENDIX 149
HYBRID TANDEM SOLAR CELLS 149

(1) Archer, M. D.; Green, M. A.Clean Electricity from Photovoltaics; World Scientific, 2014; Vol. 4.
(2) ISE Photovoltaics Report. ISE, Fraunhofer 2016.
(3) Shockley, W.; Queisser, H. J.Detailed Balance Limit of Efficiency of P‐n Junction Solar Cells. J. Appl. Phys. 1961, 32, 510–519.
(4) Richter, A.Silicon Solar Cells with Full-Area Passivated Rear Contacts: Influence of Wafer Resistivity on Device Performance on a 25% Efficiency Level. In Photovoltaic Science and Engineering Conference (PVSEC-26); Singapore, 2016.
(5) Werner, T.Analyst Day. In SunPower Analyst Day; 2015.
(6) First Solar Achieves yet Another Cell Conversion Efficiency World Record. First Sol. Press Release 2016.
(7) Köntges, M.; Siebert, M.; Morlier, A.; Illing, R.; Bessing, N.; Wegert, F.Impact of Transportation on Silicon Wafer‐based Photovoltaic Modules. Prog. Photovoltaics Res. Appl. 2016, 24, 1085–1095.
(8) Han, H.-V.; Lin, C.-C.; Tsai, Y.-L.; Chen, H.-C.; Chen, K.-J.; Yeh, Y.-L.; Lin, W.-Y.; Kuo, H.-C.; Yu, P.A Highly Efficient Hybrid GaAs Solar Cell Based on Colloidal-Quantum-Dot-Sensitization. Sci. Rep. 2014, 4, 5734.
(9) Kato, T.; (Atsugi Research Center; /Solar Frontier K.K.).Recent Research Progress of High-Efficiency CIGS Solar Cell in Solar Frontier. In 32nd EU PVSEC; 2016; pp. 20–24.
(10) First Solar Hits Record 22.1% Conversion Efficiency for CdTe Solar Cell. Greentech Media 2016.
(11) Sai, H.; Matsui, T.; Koida, T.; Matsubara, K.; Kondo, M.; Sugiyama, S.; Katayama, H.; Takeuchi, Y.; Yoshida, I.Triple-Junction Thin-Film Silicon Solar Cell Fabricated on Periodically Textured Substrate with a Stabilized Efficiency of 13.6%. Appl. Phys. Lett. 2015, 106, 213902.
(12) Zhou, Y.; Zhu, K.Perovskite Solar Cells Shine in the Valley of the Sun. ACS Energy Lett. 2016, 1, 64–67.
(13) Mathew, S.; Yella, A.; Gao, P.; Humphry-Baker, R.; Curchod, B. F. E.; Ashari-Astani, N.; Tavernelli, I.; Rothlisberger, U.; Nazeeruddin, M. K.; Grätzel, M.Dye-Sensitized Solar Cells with 13% Efficiency Achieved through the Molecular Engineering of Porphyrin Sensitizers. Nat. Chem. 2014, 6, 242–247.
(14) Kim, J.; Hiroi, H.; Todorov, T. K.; Gunawan, O.; Kuwahara, M.; Gokmen, T.; Nair, D.; Hopstaken, M.; Shin, B.; Lee, Y. S.High Efficiency Cu2ZnSn (S, Se) 4 Solar Cells by Applying a Double In2S3/CdS Emitter. Adv. Mater. 2014, 26, 7427–7431.
(15) Yan, K.; Wei, Z.; Li, J.; Chen, H.; Yi, Y.; Zheng, X.; Long, X.; Wang, Z.; Wang, J.; Xu, J.High‐Performance Graphene‐Based Hole Conductor‐Free Perovskite Solar Cells: Schottky Junction Enhanced Hole Extraction and Electron Blocking. Small 2015, 11, 2269–2274.
(16) AbuShama, J.; Noufi, R.; Johnston, S.; Ward, S.; Wu, X.Improved Performance in CuInSe2 and Surface-Modified CuGaSe2 Solar Cells. In Conference Record of the 31st IEEE Photovoltaic Specialists Conference (31st PVSC); 2005; pp. 299–302.
(17) Ishizuka, S.; Yamada, A.; Fons, P. J.; Shibata, H.; Niki, S.Structural Tuning of Wide-Gap Chalcopyrite CuGaSe 2 Thin Films and Highly Efficient Solar Cells: Differences from Narrow-Gap Cu(In,Ga)Se 2. Prog. Photovoltaics Res. Appl. 2014, 821–829.
(18) Green, M. A.; Ho-Baillie, A.; Snaith, H. J.The Emergence of Perovskite Solar Cells. Nat. Photonics 2014, 8, 506–514.
(19) Tuttle, J. R.; Ward, J. S.; Duda, A.; Berens, T. A.; Contreras, M. A.; Ramanathan, K. R.; Tennant, A. L.; Keane, J.; Cole, E. D.; Emery, K.Thin Films for Photovoltaic and Related Device Applications; San Francisco, USA, 1996; Vol. 426.
(20) Siebentritt, S.What Limits the Efficiency of Chalcopyrite Solar Cells. Sol. Energy Mater. Sol. Cells 2011, 95, 1471–1476.
(21) Contreras, M. A.; Mansfield, L. M.; Egaas, B.; Li, J.; Romero, M.; Noufi, R.; Rudiger-Voigt, E.; Mannstadt, W.Improved Energy Conversion Efficiency in Wide Bandgap Cu(In, Ga)Se2 Solar Cells. In 37th IEEE Photovoltaic Specialists Conference(37thPVSC); IEEE, 2011; pp. 26–31.
(22) Kessler, F.; Rudmann, D.Technological Aspects of Flexible CIGS Solar Cells and Modules. Sol. Energy 2004, 77, 685–695.
(23) Kapur, V. K.; Singh, P.; Choudary, U.V.; Uno, F. M.; Elyash, L.; Meisel, S.Metallization Systems for Thin Film CuInSe2/CdS Solar Cells. In 17th Photovoltaic Specialists Conference; 1984; Vol. 1, pp. 777–780.
(24) Raud, S.; Nicolet, M.-A.Study of the CuInSe2/Mo Thin Film Contact Stability. Thin Solid Films 1991, 201, 361–371.
(25) Kamikawa‐Shimizu, Y.; Shimada, S.; Watanabe, M.; Yamada, A.; Sakurai, K.; Ishizuka, S.; Komaki, H.; Matsubara, K.; Shibata, H.; Tampo, H.Effects of Mo Back Contact Thickness on the Properties of CIGS Solar Cells. Phys. Status Solidi 2009, 206, 1063–1066.
(26) Scofield, J. H.; Duda, A.; Albin, D.; Ballard, B. L.; Predecki, P. K.Sputtered Molybdenum Bilayer Back Contact for Copper Indium Diselenide-Based Polycrystalline Thin-Film Solar Cells. Thin Solid Films 1995, 260, 26–31.
(27) Kadam, A. A.; Dhere, N. G.; Holloway, P.; Law, E.Study of Molybdenum Back Contact Layer to Achieve Adherent and Efficient CIGS2 Absorber Thin-Film Solar Cells. J. Vac. Sci. Technol. A Vacuum, Surfaces, Film. 2005, 23, 1197.
(28) Kohara, N.; Nishiwaki, S.; Hashimoto, Y.; Negami, T.; Wada, T.Electrical Properties of the Cu (In, Ga)Se2/MoSe2/Mo Structure. Sol. Energy Mater. Sol. Cells 2001, 67, 209–215.
(29) Naghavi, N.; Abou-Ras, D.; Allsop, N.; Barreau, N.; Bücheler, S.; Ennaoui, A.; Fischer, C.-H.; Guillen, C.; Hariskos, D.; Herrero, J.; et al.Buffer Layers and Transparent Conducting Oxides for Chalcopyrite Cu(In,Ga)(S,Se)2 Based Thin Film Photovoltaics: Present Status and Current Developments. Prog. Photovoltaics Res. Appl. 2010, 18, 411–433.
(30) Negami, T.; Hashimoto, Y.; Nishiwaki, S.Cu (In, Ga) Se 2 Thin-Film Solar Cells with an Efficiency of 18%. Sol. energy Mater. Sol. cells 2001, 67, 331–335.
(31) Rau, U.; Schmidt, M.Electronic Properties of ZnO/CdS/Cu (In, Ga) Se 2 Solar Cells—aspects of Heterojunction Formation. Thin Solid Films 2001, 387, 141–146.
(32) Nagoya, Y.; Sang, B.; Fujiwara, Y.; Kushiya, K.; Yamase, O.Improved Performance of Cu (In, Ga) Se 2-Based Submodules with a Stacked Structure of ZnO Window Prepared by Sputtering. Sol. energy Mater. Sol. cells 2003, 75, 163–169.
(33) Rau, U.; Schmidt, M.Electronic Properties of ZnO/CdS/Cu(In,Ga)Se2 Solar Cells — Aspects of Heterojunction Formation. Thin Solid Films 2001, 387, 141–146.
(34) Hagiwara, Y.; Nakada, T.; Kunioka, A.Improved J Sc in CIGS Thin Film Solar Cells Using a Transparent Conducting ZnO: B Window Layer. Sol. Energy Mater. Sol. Cells 2001, 67, 267–271.
(35) Gupta, A.; Compaan, A. D.All-Sputtered 14% CdS/CdTe Thin-Film Solar Cell with ZnO: Al Transparent Conducting Oxide. Appl. Phys. Lett. 2004, 85.
(36) Sheu, J.-K.; Shu, K. W.; Lee, M.-L.; Tun, C.-J.; Chi, G.-C.Effect of Thermal Annealing on Ga-Doped ZnO Films Prepared by Magnetron Sputtering. J. Electrochem. Soc. 2007, 154, H521–H524.
(37) Kusinski, G. J.; Jokisaari, J. R.; Noriega, R.; Goris, L.; Donovan, M.; Salleo, A.Transmission Electron Microscopy of Solution‐processed, Intrinsic and Al‐doped ZnO Nanowires for Transparent Electrode Fabrication. J. Microsc. 2010, 237, 443–449.
(38) Calnan, S.; Tiwari, A. N.High Mobility Transparent Conducting Oxides for Thin Film Solar Cells. Thin Solid Films 2010, 518, 1839–1849.
(39) Mohammadi, S.; Abdizadeh, H.; Golobostanfard, M. R.Opto-Electronic Properties of Molybdenum Doped Indium Tin Oxide Nanostructured Thin Films Prepared via Sol–gel Spin Coating. Ceram. Int. 2013, 39, 6953–6961.
(40) Peng, C.-Y.; Hamasha, M. M.; VanHart, D.; Lu, S.; Westgate, C. R.Electrical and Optical Degradation Studies on AZO Thin Films under Cyclic Bending Conditions. Device Mater. Reliab. IEEE Trans. 2013, 13, 236–244.
(41) Jackson, P.; Würz, R.; Rau, U.; Mattheis, J.; Kurth, M.; Schlötzer, T.; Bilger, G.; Werner, J. H.High Quality Baseline for High Efficiency, Cu (In1− X, Gax) Se2 Solar Cells. Prog. Photovoltaics Res. Appl. 2007, 15, 507–519.
(42) Park, J. S.; Dong, Z.; Kim, S.; Perepezko, J. H.CuInSe2 Phase Formation during Cu2Se/In2Se3 Interdiffusion Reaction. J. Appl. Phys. 2000, 87, 3683.
(43) Scheer, R.; Schock, H.-W.Chalcogenide Photovoltaics: Physics, Technologies, and Thin Film Devices; John Wiley & Sons, 2011.
(44) Herberholz, R.; Rau, U.; Schock, H. W.; Haalboom, T.; Gödecke, T.; Ernst, F.; Beilharz, C.; Benz, K. W.; Cahen, D.Phase Segregation, Cu Migration and Junction Formation in Cu(In, Ga)Se 2. Eur. Phys. J. Appl. Phys. 1999, 6, 131–139.
(45) Beilharz, C.Charakterisierung von Aus Der Schmelze Gezüchteten Kristallen in Den Systemen Kupfer-Indium-Selen Und Kupfer-Indium-Gallium-Selen Für Photovoltaische Anwendungen; Shaker, 1999.
(46) Zhang, S. B.; Wei, S.-H.; Zunger, A.; Katayama-Yoshida, H.Defect Physics of the CuInSe 2 Chalcopyrite Semiconductor. Phys. Rev. B 1998, 57, 9642–9656.
(47) Yuan, Z.-K.; Chen, S.; Xie, Y.; Park, J.-S.; Xiang, H.; Gong, X.-G.; Wei, S.-H.Na-Diffusion Enhanced P-Type Conductivity in Cu(In,Ga)Se2 : A New Mechanism for Efficient Doping in Semiconductors. Adv. Energy Mater. 2016, 1601191.
(48) Cao, Q.; Gunawan, O.; Copel, M.; Reuter, K. B.; Chey, S. J.; Deline, V. R.; Mitzi, D. B.Defects in Cu(In,Ga)Se2 Chalcopyrite Semiconductors: A Comparative Study of Material Properties, Defect States, and Photovoltaic Performance. Adv. Energy Mater. 2011, 1, 845–853.
(49) Lany, S.; Zunger, A.Light- and Bias-Induced Metastabilities in Cu(In,Ga)Se2 Based Solar Cells Caused by the (VSe-VCu) Vacancy Complex. J. Appl. Phys. 2006, 100, 113725.
(50) Hsu, C.-H.; Su, Y.-S.; Wei, S.-Y.; Chen, C.-H.; Ho, W.-H.; Chang, C.; Wu, Y.-H.; Lin, C.-J.; Lai, C.-H.Na-Induced Efficiency Boost for Se-Deficient Cu(In,Ga)Se 2 Solar Cells. Prog. Photovoltaics Res. Appl. 2015, 23, 1621–1629.
(51) Wei, S.-H.; Zhang, S. B.; Zunger, A.Effects of Ga Addition to CuInSe2 on Its Electronic, Structural, and Defect Properties. Appl. Phys. Lett. 1998, 72, 3199.
(52) Alonso, M. I.; Garriga, M.; Rincón, C. A. D.; Hernández, E.; León, M.Optical Functions of Chalcopyrite CuGaxIn1-xSe2 Alloys. Appl. Phys. A 2002, 74, 659–664.
(53) Minoura, S.; Kodera, K.; Maekawa, T.; Miyazaki, K.; Niki, S.; Fujiwara, H.Dielectric Function of Cu (In, Ga) Se2-Based Polycrystalline Materials. J. Appl. Phys. 2013, 113, 63505.
(54) Contreras, M. A.; Mansfield, L. M.; Egaas, B.; Li, J.; Romero, M.; Noufi, R.; Rudiger-Voigt, E.; Mannstadt, W.Wide Bandgap Cu(In,Ga)Se 2 Solar Cells with Improved Energy Conversion Efficiency. Prog. Photovoltaics Res. Appl. 2012, 20, 843–850.
(55) Sites, J. R.; Granata, J. E.; Hiltner, J. F.Losses due to Polycrystallinity in Thin-Film Solar Cells. Sol. Energy Mater. Sol. Cells 1998, 55, 43–50.
(56) Seager, C. H.; Ginley, D. S.; Zook, J. D.Improvement of Polycrystalline Silicon Solar Cells with Grain‐boundary Hydrogenation Techniques. Appl. Phys. Lett. 1980, 36, 831–833.
(57) Jaffe, J.; Zunger, A.Defect-Induced Nonpolar-to-Polar Transition at the Surface of Chalcopyrite Semiconductors. Phys. Rev. B 2001, 64, 241304.
(58) Zhang, S. B.; Wei, S.-H.Reconstruction and Energetics of the Polar (112) and ( 1 ¯ 1 ¯ 2 ¯ ) versus the Nonpolar (220) Surfaces of CuInSe 2. Phys. Rev. B 2002, 65, 81402.
(59) Jain, M.II-VI Semiconductor Compounds; World Scientific, 1993.
(60) Persson, C.; Zunger, A.Anomalous Grain Boundary Physics in Polycrystalline C U I N S E 2 : The Existence of a Hole Barrier. Phys. Rev. Lett. 2003, 91, 266401.
(61) Jiang, C.-S.; Noufi, R.; AbuShama, J. A.; Ramanathan, K.; Moutinho, H. R.; Pankow, J.; Al-Jassim, M. M.Local Built-in Potential on Grain Boundary of Cu(In,Ga)Se2 Thin Films. Appl. Phys. Lett. 2004, 84, 3477.
(62) Jiang, C.-S.; Noufi, R.; Ramanathan, K.; AbuShama, J. A.; Moutinho, H. R.; Al-Jassim, M. M.Does the Local Built-in Potential on Grain Boundaries of Cu(In,Ga)Se2 Thin Films Benefit Photovoltaic Performance of the Device. Appl. Phys. Lett. 2004, 85, 2625.
(63) Hetzer, M. J.; Strzhemechny, Y. M.; Gao, M.; Contreras, M. A.; Zunger, A.; Brillson, L. J.Direct Observation of Copper Depletion and Potential Changes at Copper Indium Gallium Diselenide Grain Boundaries. Appl. Phys. Lett. 2005, 86, 162105.
(64) Azulay, D.; Millo, O.; Balberg, I.; Schock, H.-W.; Visoly-Fisher, I.; Cahen, D.Current Routes in Polycrystalline CuInSe2 and Cu(In,Ga)Se2 Films. Sol. energy Mater. Sol. cells 2007, 91, 85–90.
(65) Shin, R. H.; Jo, W.; Kim, D.-W.; Yun, J. H.; Ahn, S.Local Current-Voltage Behaviors of Preferentially and Randomly Textured Cu(In, Ga)Se2 Thin Films Investigated by Conductive Atomic Force Microscopy. Appl. Phys. A 2011, 104, 1189–1194.
(66) Mönig, H.; Smith, Y.; Caballero, R.; Kaufmann, C. A.; Lauermann, I.; Lux-Steiner, M. C.; Sadewasser, S.Direct Evidence for a Reduced Density of Deep Level Defects at Grain Boundaries of Cu (In,Ga)Se2 Thin Films. Phys. Rev. Lett. 2010, 105, 116802.
(67) Yan, Y.; Jiang, C.-S.; Noufi, R.; Wei, S.-H.; Moutinho, H. R.; Al-Jassim, M. M.Electrically Benign Behavior of Grain Boundaries in Polycrystalline CuInSe 2 Films. Phys. Rev. Lett. 2007, 99, 235504.
(68) Contreras, M. A.; Egaas, B.; Ramanathan, K.; Hiltner, J.; Swartzlander, A.; Hasoon, F.; Noufi, R.Progress toward 20% Efficiency in Cu(In,Ga)Se2 Polycrystalline Thin-Film Solar Cells. Prog. Photovoltaics Res. Appl. 1999, 7, 311–316.
(69) Chantana, J.; Watanabe, T.; Teraji, S.; Kawamura, K.; Minemoto, T.Effect of Crystal Orientation in Cu(In,Ga)Se2 Fabricated by Multi-Layer Precursor Method on Its Cell Performance. Appl. Surf. Sci. 2014, 314, 845–849.
(70) Chaisitsak, S.; Yamada, A.; Konagai, M.Preferred Orientation Control of Cu(In1-xGax)Se2 (X ≈0.28) Thin Films and Its Influence on Solar Cell Characteristics. Jpn. J. Appl. Phys. 2002, 41, 507–513.
(71) Contreras, M. A.; Jones, K. M.; Gedvilas, L.; Matson, R.Preferred Orientation in Polycrystalline Cu(In,Ga)Se2 and Its Effect on Absorber Thin-Films and Devices. 2000.
(72) Kiss, J.; Gruhn, T.; Roma, G.; Felser, C.Theoretical Study on the Structure and Energetics of Cd Insertion and Cu Depletion of CuIn5Se8. J. Phys. Chem. C 2013, 117, 10892–10900.
(73) Witte, W.; Abou-Ras, D.; Hariskos, D.Chemical Bath Deposition of Zn (O, S) and CdS Buffers: Influence of Cu (In, Ga) Se2 Grain Orientation. Appl. Phys. Lett. 2013, 102, 51607.
(74) Scheer, R.Surface and Interface Properties of Cu-Chalcopyrite Semiconductors and Devices. Trends Vac. Sci. Technol. 1997, 2, 77–112.
(75) Hanna, G.; Mattheis, J.; Laptev, V.; Yamamoto, Y.; Rau, U.; Schock, H. W.Influence of the Selenium Flux on the Growth of Cu(In,Ga)Se2 Thin Films. Thin Solid Films 2003, 431–432, 31–36.
(76) Scofield, J. H.; Asher, S.; Albin, D.; Tuttle, J.; Contreras, M.; Niles, D.; Reedy, R.; Tennant, A.; Noufi, R.Sodium Diffusion, Selenization, and Microstructural Effects Associated with Various Molybdenum Back Contact Layers for CIS-Based Solar Cells. Proc. 1994 IEEE 1st World Conf. Photovolt. Energy Convers. - WCPEC (A Jt. Conf. PVSC, PVSEC PSEC) 1994, 1, 164–167.
(77) Nakada, T.; Iga, D.; Ohbo, H.; Kunioka, A.Effects of Sodium on Cu(In,Ga)Se2-Based Thin Films and Solar Cells. Jpn. J. Appl. Phys. 1997, 36, 732–737.
(78) Kronik, L.; Cahen, D.; Schock, H. W.Effects of Sodium on Polycrystalline Cu(In,Ga)Se2 and Its Solar Cell Performance. Adv. Mater. 1998, 10, 31–36.
(79) Rudmann, D.; daCunha, A. F.; Kaelin, M.; Kurdesau, F.; Zogg, H.; Tiwari, A. N.; Bilger, G.Efficiency Enhancement of Cu(In,Ga)Se2 Solar Cells due to Post-Deposition Na Incorporation. Appl. Phys. Lett. 2004, 84, 1129.
(80) Rudmann, D.Effects of Sodium on Growth and Properties of Cu(In,Ga)Se2 Thin Films and Solar Cells, University of Basel, 2004.
(81) Ishizuka, S.; Yamada, A.; Matsubara, K.; Fons, P.; Sakurai, K.; Niki, S.Alkali Incorporation Control in Cu(In,Ga)Se2 Thin Films Using Silicate Thin Layers and Applications in Enhancing Flexible Solar Cell Efficiency. Appl. Phys. Lett. 2008, 93, 124105.
(82) Lammer, M.; Klemm, U.; Powalla, M.Sodium Co-Evaporation for Low Temperature Cu(In,Ga)Se2 Deposition. Thin Solid Films 2001, 387, 33–36.
(83) Rudmann, D.; Bilger, G.; Kaelin, M.; Haug, F.-J.; Zogg, H.; Tiwari, A. N.Effects of NaF Coevaporation on Structural Properties of Cu(In,Ga)Se2 Thin Films. Thin Solid Films 2003, 431–432, 37–40.
(84) Rudmann, D.; Bremaud, D.; Zogg, H.; Tiwari, A. N.Na Incorporation into Cu (In, Ga) Se2 for High-Efficiency Flexible Solar Cells on Polymer Foils. J. Appl. Phys. 2005, 97, 84903.
(85) Ishizuka, S.; Yamada, A.; Islam, M. M.; Shibata, H.; Fons, P.; Sakurai, T.; Akimoto, K.; Niki, S.Na-Induced Variations in the Structural, Optical, and Electrical Properties of Cu(In,Ga)Se2 Thin Films. J. Appl. Phys. 2009, 106, 34908.
(86) Stange, H.; Brunken, S.; Hempel, H.; Rodriguez-Alvarez, H.; Schäfer, N.; Greiner, D.; Scheu, A.; Lauche, J.; Kaufmann, C. A.; Unold, T.Effect of Na Presence during CuInSe2 Growth on Stacking Fault Annihilation and Electronic Properties. Appl. Phys. Lett. 2015, 107, 152103.
(87) Niles, D. W.Na Impurity Chemistry in Photovoltaic CIGS Thin Films: Investigation with X-Ray Photoelectron Spectroscopy. J. Vac. Sci. Technol. A Vacuum, Surfaces, Film. 1997, 15, 3044.
(88) Contreras, M. A.; Egaas, B.; Dippo, P.; Webb, J.; Granata, J.; Ramanathan, K.; Asher, S.; Swartzlander, A.; Noufi, R.On the Role of Na and Modifications to Cu(In,Ga)Se/sub 2/ Absorber Materials Using Thin-MF (M=Na, K, Cs) Precursor Layers. In Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997; IEEE, 1997; pp. 359–362.
(89) Schroeder, D. J.; Rockett, A. A.Electronic Effects of Sodium in Epitaxial CuIn1-xGaxSe2. J. Appl. Phys. 1997, 82, 4982–4985.
(90) Wei, S.; Zhang, S. B.; Zunger, A.Effects of Na on the Electrical and Structural Properties of CuInSe2. J. Appl. Phys. 1999, 85.
(91) Lany, S.; Zunger, A.Intrinsic D X Centers in Ternary Chalcopyrite Semiconductors. Phys. Rev. Lett. 2008, 100, 16401.
(92) Sun, X.; Jiang, F.; Feng, J.Roles of Sodium Induced Defects in CuInSe2 by First Principles Calculation. Comput. Mater. Sci. 2009, 47, 31–34.
(93) Chen, W. S.; Stewart, J. M.; Mickelsen, R. A.Polycrystalline Thin‐film Cu2− xSe/CdS Solar Cell. Appl. Phys. Lett. 1985, 46, 1095–1097.
(94) Mickelsen, R. A.; Chen, W. S.High Photocurrent Polycrystalline Thin‐film CdS/CuInSe2 Solar Cella. Appl. Phys. Lett. 1980, 36, 371–373.
(95) Mickelsen, R. A.; Chen, W. S.Methods for Forming Thin-Film Heterojunction Solar Cells from I-III-VI.sub.2 U.S. Patent No. 4,335,266, June15, 1982.
(96) Tuttle, J. R.; Contreras, M.; Tennant, A.; Albin, D.; Noufi, R.High Efficiency Thin-Film Cu(In,Ga)Se2-Based Photovoltaic Devices: Progress towards a Universal Approach to Absorber Fabrication. In Photovoltaic Specialists Conference, 1993., Conference Record of the Twenty Third IEEE; IEEE, 1993; pp. 415–421.
(97) Contreras, M. A.; Tuttle, J.; Gabor, A.; Tennant, A.; Ramanathan, K.; Asher, S.; Franz, A.; Keane, J.; Wang, L.; Scofield, J.High Efficiency Cu(In,Ga)Se2-Based Solar Cells: Processing of Novel Absorber Structures. In Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference-1994, 1994 IEEE First World Conference; IEEE, 1994; Vol. 1, pp. 68–75.
(98) Jackson, P.; Hariskos, D.; Lotter, E.; Paetel, S.; Wuerz, R.; Menner, R.; Wischmann, W.; Powalla, M.New World Record Efficiency for Cu(In,Ga)Se2 Thin-Film Solar Cells beyond 20%. Prog. Photovoltaics Res. Appl. 2011, 19, 894–897.
(99) Chirilă, A.; Reinhard, P.; Pianezzi, F.; Bloesch, P.; Uhl, A. R.; Fella, C.; Kranz, L.; Keller, D.; Gretener, C.; Hagendorfer, H.; et al.Potassium-Induced Surface Modification of Cu(In,Ga)Se2 Thin Films for High-Efficiency Solar Cells. Nat. Mater. 2013, 12, 1107–1111.
(100) Chirilă, A.; Buecheler, S.; Pianezzi, F.; Bloesch, P.; Gretener, C.; Uhl, A. R.; Fella, C.; Kranz, L.; Perrenoud, J.; Seyrling, S.; et al.Highly Efficient Cu(In,Ga)Se2 Solar Cells Grown on Flexible Polymer Films. Nat. Mater. 2011, 10, 857–861.
(101) Jackson, P.; Hariskos, D.; Wuerz, R.; Wischmann, W.; Powalla, M.Compositional Investigation of Potassium Doped Cu(In,Ga)Se 2 Solar Cells with Efficiencies up to 20.8%. Phys. Status Solidi - Rapid Res. Lett. 2014, 8, 219–222.
(102) Contreras, M. A.; Repins, I.; Metzger, W. K.; Romero, M.; Abou-Ras, D.Se Activity and Its Effect on Cu(In,Ga)Se2 Photovoltaic Thin Films. Phys. Status Solidi 2009, 206, 1042–1048.
(103) Young Park, H.; Gwon Moon, D.; Ho Yun, J.; Ahn, S. K.; Yoon, K. H.; Ahn, S.Efficiency Limiting Factors in Cu(In,Ga)Se2 Thin Film Solar Cells Prepared by Se-Free Rapid Thermal Annealing of Sputter-Deposited Cu-In-Ga-Se Precursors. Appl. Phys. Lett. 2013, 103, 263903.
(104) Islam, M. M.; Uedono, A.; Sakurai, T.; Yamada, A.; Ishizuka, S.; Matsubara, K.; Niki, S.; Akimoto, K.Impact of Se Flux on the Defect Formation in Polycrystalline Cu(In,Ga)Se2 Thin Films Grown by Three Stage Evaporation Process. J. Appl. Phys. 2013, 113, 64907.
(105) Powalla, M.; Dimmler, B.Development of Large-Area CIGS Modules. Sol. energy Mater. Sol. cells 2003, 75, 27–34.
(106) Lindahl, J.; Zimmermann, U.; Szaniawski, P.; Torndahl, T.; Hultqvist, A.; Salome, P.; Platzer-Bjorkman, C.; Edoff, M.Inline Cu(In,Ga)Se2 Co-Evaporation for High-Efficiency Solar Cells and Modules. IEEE J. Photovoltaics 2013, 3, 1100–1105.
(107) Kushiya, K.; Tachiyuki, M.; Kase, T.Thin-Film Solar Cell Comprising Thin-Film Light Absorbing Layer of Chalcopyrite Multi-Element Compound Semiconductor U.S. Patent No. 5,981,868, November9, 1999.
(108) Kapur, V. K.; Choudary, U.V; Chu, A. K. P.Process of Forming a Compound Semiconductive Material U.S. Patent No. 4, 581, 108, April8, 1986.
(109) Jensen, C. L.; Tarrant, D. E.; Ermer, J. H.; Pollock, G. A.The Role of Gallium in CuInSe 2 Solar Cells Fabricated by a Two-Stage Method. In Photovoltaic Specialists Conference, 1993., Conference Record of the Twenty Third IEEE; IEEE, 1993; pp. 577–580.
(110) Kushiya, K.; Tanaka, Y.; Hakuma, H.; Goushi, Y.; Kijima, S.; Aramoto, T.; Fujiwara, Y.Interface Control to Enhance the Fill Factor over 0.70 in a Large-Area CIS-Based Thin-Film PV Technology. Thin Solid Films 2009, 517, 2108–2110.
(111) Kushiya, K.Key near-Term R&D Issues for Continuous Improvement in CIS-Based Thin-Film PV Modules. Sol. Energy Mater. Sol. Cells 2009, 93, 1037–1041.
(112) Nakamura, M.; Kouji, Y.; Chiba, Y.; Hakuma, H.; Kobayashi, T.; Nakada, T.Achievement of 19.7% Efficiency with a Small-Sized Cu (InGa)(SeS)2 Solar Cells Prepared by Sulfurization after Selenizaion Process with Zn-Based Buffer. In 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC); IEEE, 2013; pp. 849–852.
(113) Nagoya, Y.; Kushiya, K.; Tachiyuki, M.; Yamase, O.Role of Incorporated Sulfur into the Surface of Cu (InGa) Se 2 Thin-Film Absorber. Sol. energy Mater. Sol. cells 2001, 67, 247–253.
(114) Niki, S.; Contreras, M.; Repins, I.; Powalla, M.; Kushiya, K.; Ishizuka, S.; Matsubara, K.CIGS Absorbers and Processes. Prog. Photovoltaics Res. Appl. 2010, 18, 453–466.
(115) Piekoszewski, J.; Loferski, J. J.; Beaulieu, R.; Beall, J.; Roessler, B.; Shewchun, J.RF-Sputtered CuInSe2 Thin Films. Sol. Energy Mater. 1980, 2, 363–372.
(116) Thornton, J. A.; Lommasson, T. C.Magnetron Reactive Sputtering of Copper-Indium-Selenide. Sol. Cells 1986, 16, 165–180.
(117) Shi, J. H.; Li, Z. Q.; Zhang, D. W.; Liu, Q. Q.; Sun, Z.; Huang, S. M.Fabrication of Cu(In, Ga)Se2 Thin Films by Sputtering from a Single Quaternary Chalcogenide Target. Prog. Photovoltaics Res. Appl. 2011, 19, 160–164.
(118) Edoff, M.; Lindahl, J.; Wätjen, T.; Nyber, T.Gas Flow Sputtering of Cu (In, Ga) Se2 for Thin Film Solar Cells. In Photovoltaic Specialist Conference (PVSC), 2015 IEEE 42nd; IEEE, 2015; pp. 1–5.
(119) Frantz, J. A.; Bekele, R. Y.; Nguyen, V. Q.; Sanghera, J. S.; Bruce, A.; Frolov, S. V.; Cyrus, M.; Aggarwal, I. D.Cu(In,Ga)Se2 Thin Films and Devices Sputtered from a Single Target without Additional Selenization. Thin Solid Films 2011, 519, 7763–7765.
(120) Chen, C.-H.; Shih, W.-C.; Chien, C.-Y.; Hsu, C.-H.; Wu, Y.-H.; Lai, C.-H.A Promising Sputtering Route for One-Step Fabrication of Chalcopyrite Phase Cu(In,Ga)Se2 Absorbers without Extra Se Supply. Sol. Energy Mater. Sol. Cells 2012, 103, 25–29.
(121) Hsu, C.-H.; Ho, W.-H.; Yuan, W.-S.; Lai, C.-H.Over 14% Efficiency of Directly Sputtered Cu(In,Ga)Se2 Absorbers without Post-Selenization by Post-Treatment of Alkali Metals. Adv. Energy Mater. 2017, (Accepted).
(122) Ouyang, L.; Zhuang, D.; Zhao, M.; Zhang, N.; Li, X.; Guo, L.; Sun, R.; Cao, M.Cu(In,Ga)Se 2 Solar Cell with 16.7% Active-Area Efficiency Achieved by Sputtering from a Quaternary Target. Phys. Status Solidi 2015, 212, 1774–1778.
(123) Lin, T.-Y.; Chen, C.-H.; Huang, W.-C.; Ho, W.-H.; Wu, Y.-H.; Lai, C.-H.Direct Probing Se Spatial Distribution in Cu(InxGa1-x)Se2 Solar Cells: A Key Factor to Achieve High Efficiency Performance. Nano Energy 2016, 19, 269–278.
(124) Mori, N.Micro Area Analysis with JXA-8530 (FE-EPMA). JEOL News 2010, 45, 42–46.
(125) Kiss, J.; Gruhn, T.; Roma, G.; Felser, C.Theoretical Study on the Diffusion Mechanism of Cd in the Cu-Poor Phase of CuInSe2 Solar Cell Material. J. Phys. Chem. C 2013, 117, 25933–25938.
(126) Matsumori, H.; Nakada, T.Epitaxial Growth of CIGS Thin Films on Mo-Coated Sapphire Substrates. In 19th International Conference Ternary and Multinary Compound; Niigata, Japan, 2014; pp. P4-131.
(127) Contreras, M. A.; Egaas, B.; King, D.; Swartzlander, A.; Dullweber, T.Texture Manipulation of CuInSe2 Thin Films. Thin Solid Films 2000, 361–362, 167–171.
(128) Shin, D. H.; Shin, Y. M.; Kim, J. H.; Ahn, B. T.; Yoon, K. H.Control of the Preferred Orientation of Cu(In,Ga)Se2 Thin Film by the Surface Modification of Mo Film. J. Electrochem. Soc. 2012, 159, B1.
(129) Ahn, S.; Kim, K. H.; Yun, J. H.; Yoon, K. H.Effects of Selenization Conditions on Densification of Cu(In,Ga)Se2 (CIGS) Thin Films Prepared by Spray Deposition of CIGS Nanoparticles. J. Appl. Phys. 2009, 105, 113533.
(130) Shin, B.; Zhu, Y.; Bojarczuk, N. A.; Jay Chey, S.; Guha, S.Control of an Interfacial MoSe2 Layer in Cu2ZnSnSe4 Thin Film Solar Cells: 8.9% Power Conversion Efficiency with a TiN Diffusion Barrier. Appl. Phys. Lett. 2012, 101, 53903.
(131) Schroeder, D. J.; Rockett, A. A.Electronic Effects of Sodium in Epitaxial CuIn1−xGaxSe2. J. Appl. Phys. 1997, 82, 4982–4985.
(132) Chen, C.-H.; Lin, T.-Y.; Hsu, C.-H.; Wei, S.-Y.; Lai, C.-H.Comprehensive Characterization of Cu-Rich Cu(In,Ga)Se2 Absorbers Prepared by One-Step Sputtering Process. Thin Solid Films 2013, 535, 122–126.
(133) Salomé, P. M. P.; Fjällström, V.; Szaniawski, P.; Leitão, J. P.; Hultqvist, A.; Fernandes, P. A.; Teixeira, J. P.; Falcão, B. P.; Zimmermann, U.; daCunha, A. F.; et al.A Comparison between Thin Film Solar Cells Made from Co-Evaporated CuIn1-xGaxSe2 Using a One-Stage Process versus a Three-Stage Process. Prog. Photovoltaics Res. Appl. 2015, 23, 470–478.
(134) Rampino, S.; Bissoli, F.; Gilioli, E.; Pattini, F.Growth of Cu(In,Ga)Se 2 Thin Films by a Novel Single-Stage Route Based on Pulsed Electron Deposition. Prog. Photovoltaics Res. Appl. 2013, 588–594.
(135) Rockett, A.The Electronic Effects of Point Defects in Cu (InxGa1-x)Se2. 2000, 362, 330–337.
(136) Goldstein, J. I.; Newbury, D. E.; Echlin, P.; Joy, D. C.; Lyman, C. E.; Lifshin, E.; Sawyer, L.; Michael, J. R.Scanning Electron Microscopy and X-Ray Microanalysis; Springer US: Boston, MA, 2003.
(137) Stoney, G. G.The Tension of Metallic Films Deposited by Electrolysis. Proc. R. Soc. A Math. Phys. Eng. Sci. 1909, 82, 172–175.
(138) Thornton, J. A.High Rate Thick Film Growth. Annu. Rev. Mater. Sci. 1977, 7, 239–260.
(139) Mattox, D. M.Particle Bombardment Effects on Thin-Film Deposition: A Review. J. Vac. Sci. Technol. A Vacuum, Surfaces, Film. 1989, 7, 1105.
(140) Segmüller, A.; Angilelo, J.; LaPlaca, S. J.Automatic X-Ray Diffraction Measurement of the Lattice Curvature of Substrate Wafers for the Determination of Linear Strain Patterns. J. Appl. Phys. 1980, 51, 6224.
(141) Müller, K.-H.Stress and Microstructure of Sputter-Deposited Thin Films: Molecular Dynamics Investigations. J. Appl. Phys. 1987, 62, 1796.
(142) Ayers, J.Heteroepitaxy of Semiconductors : Theory, Growth, and Characterization; CRC Press: Boca Raton, Florida, 2007.
(143) Lee, S.; Koo, J.; Kim, S.; Kim, S.-H.; Cheon, T.; Oh, J. S.; Kim, S. J.; Kim, W. K.Characteristics of MoSe 2 Formation during Rapid Thermal Processing of Mo-Coated Glass. Thin Solid Films 2013, 535, 206–213.
(144) Abou-Ras, D.; Kostorz, G.; Bremaud, D.; Kälin, M.; Kurdesau, F. V.; Tiwari, A. N.; Döbeli, M.Formation and Characterisation of MoSe2 for Cu(In,Ga)Se2 Based Solar Cells. Thin Solid Films 2005, 480–481, 433–438.
(145) Oikkonen, L. E.; Ganchenkova, M. G.; Seitsonen, A. P.; Nieminen, R. M.Effect of Sodium Incorporation into CuInSe2 from First Principles. J. Appl. Phys. 2013, 114, 83503.
(146) Contreras, M. A.; Tuttle, J. R.; Gabor, A.; Tennant, A.; Ramanathan, K.; Asher, S.; Franz, A.; Keane, J.; Wang, L.; Scofield, J.; et al.High Efficiency Cu(In,Ga)Se2-Based Solar Cells: Processing of Novel Absorber Structures. In Conference Record of the 24th IEEE Photovoltaics Specialists Conference (PVSC); Hawaii, December, 1994.
(147) Powalla, M.; Dimmler, B.CIGS Solar Cells on the Way to Mass Production: Process Statistics of a 30cm×30cm Module Line. Sol. Energy Mater. Sol. Cells 2001, 67, 337–344.
(148) Delahoy, A. E.; Chen, L.; Akhtar, M.; Sang, B.; Guo, S.New Technologies for CIGS Photovoltaics. Sol. Energy 2004, 77, 785–793.
(149) Alberts, V.; Titus, J.; Birkmire, R. W.Material and Device Properties of Single-Phase Cu(In,Ga)(Se,S)2 Alloys Prepared by Selenization/sulfurization of Metallic Alloys. Thin Solid Films 2004, 451–452, 207–211.
(150) Wu, T.-T.; Huang, J.-H.; Hu, F.; Chang, C.; Liu, W.-L.; Wang, T.-H.; Shen, C.-H.; Shieh, J.-M.; Chueh, Y.-L.Toward High Efficiency and Panel Size 30×40cm2 Cu(In,Ga)Se2 Solar Cell: Investigation of Modified Stacking Sequences of Metallic Precursors and Pre-Annealing Process without Se Vapor at Low Temperature. Nano Energy 2014, 10, 28–36.
(151) Todorov, T. K.; Gunawan, O.; Gokmen, T.; Mitzi, D. B.Solution-Processed Cu(In,Ga)(S,Se) 2 Absorber Yielding a 15.2% Efficient Solar Cell. Prog. Photovoltaics Res. Appl. 2013, 21, 82–87.
(152) Lincot, D.; Guillemoles, J. F.; Taunier, S.; Guimard, D.; Sicx-Kurdi, J.; Chaumont, A.; Roussel, O.; Ramdani, O.; Hubert, C.; Fauvarque, J. P.; et al.Chalcopyrite Thin Film Solar Cells by Electrodeposition. Sol. Energy 2004, 77, 725–737.
(153) Kapur, V. K.; Bansal, A.; Le, P.; Asensio, O. I.Non-Vacuum Processing of CuIn1−xGaxSe2 Solar Cells on Rigid and Flexible Substrates Using Nanoparticle Precursor Inks. Thin Solid Films 2003, 431–432, 53–57.
(154) Li, W.; Sun, Y.; Liu, W.; Zhou, L.Fabrication of Cu(In,Ga)Se2 Thin Films Solar Cell by Selenization Process with Se Vapor. Sol. Energy 2006, 80, 191–195.
(155) Nishiwaki, S.; Kohara, N.; Negami, T.; Miyake, H.; Wada, T.Microstructure of Cu(In,Ga)Se 2 Films Deposited in Low Se Vapor Pressure. Jpn. J. Appl. Phys. 1999, 38, 2888–2892.
(156) Zhang, S.; Wei, S.-H.; Zunger, A.; Katayama-Yoshida, H.Defect Physics of the CuInSe2 Chalcopyrite Semiconductor. Phys. Rev. B 1998, 57, 9642–9656.
(157) Islam, M. M.; Sakurai, T.; Ishizuka, S.; Yamada, A.; Shibata, H.; Sakurai, K.; Matsubara, K.; Niki, S.; Akimoto, K.Effect of Se/(Ga+In) Ratio on MBE Grown Cu(In,Ga)Se2 Thin Film Solar Cell. J. Cryst. Growth 2009, 311, 2212–2214.
(158) Keller, J.; Schlesiger, R.; Riedel, I.; Parisi, J.; Schmitz, G.; Avellan, A.; Dalibor, T.Grain Boundary Investigations on Sulfurized Cu(In,Ga)(S,Se)2 Solar Cells Using Atom Probe Tomography. Sol. Energy Mater. Sol. Cells 2013, 117, 592–598.
(159) Cojocaru-Mirédin, O.; Choi, P.; Wuerz, R.; Raabe, D.Atomic-Scale Distribution of Impurities in CuInSe2-Based Thin-Film Solar Cells. Ultramicroscopy 2011, 111, 552–556.
(160) Drouin, D.; Couture, A. R.; Joly, D.; Tastet, X.; Aimez, V.; Gauvin, R.CASINO V2.42: A Fast and Easy-to-Use Modeling Tool for Scanning Electron Microscopy and Microanalysis Users. Scanning 2007, 29, 92–101.
(161) Hegedus, S. S.; Shafarman, W. N.Thin-Film Solar Cells: Device Measurements and Analysis. Prog. Photovoltaics Res. Appl. 2004, 12, 155–176.
(162) Im, J.; Auciello, O.; Baumann, P. K.; Streiffer, S. K.; Kaufman, D. Y.; Krauss, A. R.Composition-Control of Magnetron-Sputter-Deposited (BaxSr1−x)Ti1+yO3+z Thin Films for Voltage Tunable Devices. Appl. Phys. Lett. 2000, 76, 625.
(163) Cahen, D.; Noufi, R.Defect Chemical Explanation for the Effect of Air Anneal on CdS/CuInSe2 Solar Cell Performance. Appl. Phys. Lett. 1989, 54, 558.
(164) Liao, Y.-K.; Wang, Y.-C.; Yen, Y.-T.; Chen, C.-H.; Hsieh, D.-H.; Chen, S.-C.; Lee, C.-Y.; Lai, C.-C.; Kuo, W.-C.; Juang, J.-Y.; et al.Non-Antireflective Scheme for Efficiency Enhancement of Cu(In,Ga)Se2 Nanotip Array Solar Cells. ACS Nano 2013, 7, 7318–7329.
(165) Tsuji, K.; Injuk, J.; Grieken, R.Van.X-Ray Spectrometry: Recent Technological Advances; John Wiley & Sons: West Sussex, England, 2004.
(166) Servant, J.-M.; Meny, L.; Champigny, M.Energy Dispersion Quantitative X-Ray Microanalysis on a Scanning Electron Microscope. X-Ray Spectrom. 1975, 4, 99–107.
(167) Donovan, J.High Sensitivity EPMA: Past, Present and Future. Microsc. Microanal. 2011, 17, 560–561.
(168) Cahen, D.; Noufi, R.Free Energies and Enthalpies of Possible Gas Phase and Surface Reactions for Preparation of CuInSe2. J. Phys. Chem. Solids 1992, 53, 991–1005.
(169) Aller, L. H.; Appenzeller, I.; Baschek, B.; Butler, K.; DeLoore, C.; Duerbeck, H. W.; ElEid, M. F.; Fink, H. H.; Herczeg, T.; Richtler, T.Landolt-Börnstein: Numerical Data and Functional Relationships in Science and Technology-New Series; 1996; Vol. 5a–5j.
(170) Mills, K. C.Thermodynamic Data for Inorganic Sulphides, Selenides and Tellurides. 1974.
(171) Berkowitz, J.Comment on the Composition of Selenium Vapor. J. Chem. Phys. 1968, 48, 5743.
(172) Li, G.; Liu, W.; Liu, Y.; Lin, S.; Zhang, Y.; Zhou, Z.; He, Q.; Sun, Y.The Influence of Cracked Selenium Flux on CIGS Thin Film Growth and Device Performance Prepared by Two-Step Selenization Processes. Sol. Energy Mater. Sol. Cells 2015, 139, 108–114.
(173) Sadewasser, S.Microscopic Characterization of Individual Grain Boundaries in Cu-III–VI2 Chalcopyrites. Thin Solid Films 2007, 515, 6136–6141.
(174) Azulay, D.; Millo, O.; Balberg, I.; Schock, H.-W.; Visoly-Fisher, I.; Cahen, D.Current Routes in Polycrystalline CuInSe2 and Cu(In,Ga)Se2 Films. Sol. Energy Mater. Sol. Cells 2007, 91, 85–90.
(175) Sakurai, T.; Islam, M. M.; Uehigashi, H.; Ishizuka, S.; Yamada, A.; Matsubara, K.; Niki, S.; Akimoto, K.Dependence of Se Beam Pressure on Defect States in CIGS-Based Solar Cells. Sol. Energy Mater. Sol. Cells 2011, 95, 227–230.
(176) Rau, U.; Grabitz, P. O.; Werner, J. H.Resistive Limitations to Spatially Inhomogeneous Electronic Losses in Solar Cells. Appl. Phys. Lett. 2004, 85, 6010.
(177) Hsu, C.-H.Effects of Se, Na, and K on Quaternary-Sputtered CIGS Thin Films, National Tsing Hua University, 2016.
(178) Jackson, P.; Wuerz, R.; Hariskos, D.; Lotter, E.; Witte, W.; Powalla, M.Effects of Heavy Alkali Elements in Cu(In,Ga)Se2 Solar Cells with Efficiencies up to 22.6%. Phys. status solidi (RRL)-Rapid Res. Lett. 2016, 10, 583–586.
(179) Granata, J. E.; Sites, J. R.; Asher, S.; Matson, R. J.Quantitative Incorporation of Sodium in CuInSe 2 and Cu (In, Ga) Se 2 Photovoltaic Devices. In Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE; IEEE, 1997; pp. 387–390.
(180) Hanket, G. M.; Shafarman, W. N.; McCandless, B. E.; Birkmire, R. W.Incongruent Reaction of Cu–(InGa) Intermetallic Precursors in H2Se and H2S. J. Appl. Phys. 2007, 102, 74922.
(181) Bothe, K.; Bauer, G. H.; Unold, T.Spatially Resolved Photoluminescence Measurements on Cu(In,Ga)Se2 Thin Films. Thin Solid Films 2002, 403–404, 453–456.
(182) Eich, D.; Herber, U.; Groh, U.; Stahl, U.; Heske, C.; Marsi, M.; Kiskinova, M.; Riedl, W.; Fink, R.; Umbach, E.Lateral Inhomogeneities of Cu(In,Ga)Se2 Absorber Films. Thin Solid Films 2000, 361–362, 258–262.
(183) Shiau, Y.-J.; Chiang, K.-M.; Lin, H.-W.Performance Enhancement of Metal Nanowire-Based Transparent Electrodes by Electrically Driven Nanoscale Nucleation of Metal Oxides. Nanoscale 2015, 7, 12698–12705.
(184) Braunger, D.; Zweigart, S.; Schock, H. W.The Influence of Na and Ga on the Incorporation of the Chalcogen in Polycrystalline Cu(In,Ga)(S,Se)2 Thin-Films for Photovoltaic Applications. In 2nd World Conference of Photovoltaic Solar Energy Conversion, Vienna; 1998; Vol. 1113.
(185) Braunger, D.; Hariskos, D.; Bilger, G.; Rau, U.; Schock, H. W.Influence of Sodium on the Growth of Polycrystalline Cu(In,Ga)Se2 Thin Films. Thin Solid Films 2000, 361–362, 161–166.
(186) NIST X-Ray Photoelectron Spectroscopy Database, NIST Standard Refer- ence Database 20, Version 3.4 http://srdata.nist.gov/xps/.
(187) Wagner, C. D.Chemical Shifts of Auger Lines, and the Auger Parameter. Faraday Discuss. Chem. Soc. 1975, 60, 291–300.
(188) Seyama, H.; Soma, M.Bonding-State Characterization of the Constitutent Elements of Silicate Minerals by X-Ray Photoelectron Spectroscopy. J. Chem. Soc. Faraday Trans. 1 Phys. Chem. Condens. Phases 1985, 81, 485–495.
(189) Barrie, A.; Street, F. J.An Auger and X-Ray Photoelectron Spectroscopic Study of Sodium Metal and Sodium Oxide. J. Electron Spectros. Relat. Phenomena 1975, 7, 1–31.
(190) Sites, J. R.Quantification of Losses in Thin-Film Polycrystalline Solar Cells. Sol. Energy Mater. Sol. Cells 2003, 75, 243–251.
(191) Gerthoffer, A.; Roux, F.; Emieux, F.; Faucherand, P.; Fournier, H.; Grenet, L.; Perraud, S.CIGS Solar Cells on Flexible Ultra-Thin Glass Substrates: Characterization and Bending Test. Thin Solid Films 2015, 592, 99–104.
(192) Wuerz, R.; Eicke, A.; Frankenfeld, M.; Kessler, F.; Powalla, M.; Rogin, P.; Yazdani-Assl, O.CIGS Thin-Film Solar Cells on Steel Substrates. Thin Solid Films 2009, 517, 2415–2418.
(193) Song, J.-G.; Park, K.; Park, J.; Kim, H.Vapor Deposition Techniques for Synthesis of Two-Dimensional Transition Metal Dichalcogenides. Appl. Microsc. 2015, 45, 119–125.
(194) Beiley, Z. M.; McGehee, M. D.Modeling Low Cost Hybrid Tandem Photovoltaics with the Potential for Efficiencies Exceeding 20%. Energy Environ. Sci. 2012, 5, 9173–9179.
(195) Bremner, S. P.; Levy, M. Y.; Honsberg, C. B.Analysis of Tandem Solar Cell Efficiencies under AM1.5G Spectrum Using a Rapid Flux Calculation Method. Prog. Photovoltaics Res. Appl. 2008, 16, 225–233.
(196) Bailie, C. D.; Christoforo, M. G.; Mailoa, J. P.; Bowring, A. R.; Unger, E. L.; Nguyen, W. H.; Burschka, J.; Pellet, N.; Lee, J. Z.; Grätzel, M.; et al.Semi-Transparent Perovskite Solar Cells for Tandems with Silicon and CIGS. Energy Environ. Sci. 2014, 8, 956–963.