為減緩持續惡化之全球暖化危機，人類正積極尋找石化燃料以外之乾淨、可永續利用之能源。光電催化(PEC)電解槽可透過水分解產生氫氣，或還原二氧化碳成可利用之碳氫化合物。在光電催化領域中氧化亞銅(Cu2O)為眾所注目之光陰極材料，其在可見光波段之高吸收係數、低成本、無毒與好合成等優點，使其成為主要之研究對象。然而高電子-電洞再結合率與在液相溶液中之不穩定特性阻礙其實際應用，因此對於Cu2O之研究多為降低載子再結合率以提升光電流表現，與披覆保護層阻絕與溶液之直接接觸以提高穩定性。文獻上大都以異質界面結構方式，在Cu2O電極外側披覆保護層，以兩材料能帶排列之電場效應分離光激發載子，提高光電性質表現。
本實驗以低成本之電鍍沉積法，在相同電鍍溶液條件下，以不同電鍍電流密度於FTO導電玻璃上電鍍Cu2O薄膜，成功鍍製以不同優選方向成長之Cu2O薄膜，並選擇以光電性質較佳之(111)優選方向進行性質優化，在載子擴散距離與光穿透深度間取得最佳值，發現在膜厚為0.66 μm時可得最大光電流值2.9 mA/cm2，高於文獻平均2 mA/cm2許多。接著同樣以能帶結構排列之概念，在FTO基板與Cu2O薄膜間引入該領域未被使用過之Cu2Te，作為電洞傳輸層，提高載子分離效率以提升光電流。結果證實引入Cu2Te後，Cu2O薄膜之光電流值由2.9 提升至4.9 mA/cm2，效果相當顯著，且光激發螢光光譜(PL)之結果證實Cu2Te能降低Cu2O中之載子再結合率，顯示Cu2Te能透過能帶結構排列產生之電場效應提升Cu2O光電流表現。最後則針對Cu2O薄膜中空位缺陷進行分析，發現氧空位缺陷僅分佈於薄膜表面，且電鍍於FTO上或Cu2Te上之分佈沒有差異，氧空位缺陷能提高載子生命週期，降低再結合率，提高光電流。而銅空位缺陷能提高Cu2O之主要載子濃度，提高電荷傳輸效率，提升Cu2O薄膜光電性能。

A clean and sustainable energy source other than fossil fuel is highly desired to avoid the continuous deterioration of global warming crisis. A photoelectrochemical (PEC) cell can be used to produce hydrogen fuel and hydrocarbon derivatives through water splitting and reduction of carbon dioxide gas, respectively. Cuprous oxide (Cu2O) is a well-known photocathode material in a PEC cell owing to its advantages of high absorption coefficient in visible light range, low-cost, non-toxicity and ease of fabrication. However, the chemical instability in aqueous solution and high electron-hole recombination rate have prevented the Cu2O from practical PEC applications. Some research indicated that the photoelectrochemical performance of Cu2O can be enhanced through heterogeneous junction structure. By depositing a protection layer on the Cu2O film, photoexcited carriers can be separated by the electric field established at the junction, leading to improved photoelectric properties.
In this study, a low-cost electrodeposition method is used to deposit Cu2O thin film on the fluorine-doped tin oxide (FTO) glass substrate with different electrodeposition current density. The Cu2O thin films were grown with different preferred orientations by adjusting the applied current density. Further optimizations including Cu2O film thickness adjustments and insertion of Cu2Te were done on the well performed (111) oriented Cu2O films. We found that the 0.66 μm-thick Cu2O film shows the maximum photocurrent density of 2.9 mA/cm2, which is much higher than the reported value around 2 mA/cm2 in the literature. Next, we introduced a copper(Ⅰ) telluride (Cu2Te) as hole transmission layer between Cu2O film and the FTO substrate. The Cu2Te insertion layer can enhance the separation efficiency of photocarriers and increase the output photocurrent of Cu2O. The results showed that after the introduction of Cu2Te, the photocurrent of Cu2O thin film significantly increased from 2.9 to 4.9 mA/cm2. The photoluminescence (PL) results confirmed that Cu2Te can reduce the carrier recombination rate of Cu2O. Finally, the vacancy defects in the Cu2O thin film were analyzed. It is found that the oxygen vacancy defects are mainly located on the surface of the Cu2O film regardless the presence of Cu2Te insertion layer. Oxygen vacancy defects can increase the carrier life time, reduce the recombination rate, and increase the photocurrent. Copper vacancy defects can increase the majority carrier concentration of Cu2O film, improve the charge transfer efficiency, and improve the photoelectric performance of Cu2O thin films.

摘要 I
Abstract II
致謝 IV
目錄 VI
圖目錄 IX
表目錄 XII
第1章 緒論 1
1.1 前言 1
1.1.1 太陽能 3
1.1.2 氫能源之應用 4
1.1.3 氫氣產生方法 6
1.2 研究動機 10
第2章 文獻回顧 11
2.1 氧化亞銅(Cu2O)與其薄膜沉積技術 11
2.1.1 Cu2O的基本性質 11
2.1.2 Cu2O的研究歷史 13
2.1.3 Cu2O薄膜沉積技術 15
2.2 光催化電解水產氫 16
2.2.1 光催化電解水材料選擇 16
2.2.2 光催化電解水所面臨之問題 20
2.2.3 能帶結構排列 22
2.3 Cu2O薄膜結晶方向與氧空位缺陷(Oxygen vacancy defect) 24
2.3.1 Cu2O薄膜結晶方向與性質 24
2.3.2 Cu2O薄膜不同結晶方向之能帶 26
2.3.3 氧缺陷空位在半導體中扮演之角色 28
第3章 實驗流程 31
3.1 實驗設計與流程 31
3.1.1 實驗藥品 31
3.1.2 Cu2Te薄膜製備 32
3.1.3 Cu2O薄膜電鍍 32
3.1.4 電化學量測方法 33
3.2 電鍍Cu2O薄膜之分析 34
3.2.1 X-ray結晶繞射(XRD)分析 34
3.2.2 掃描式電子顯微鏡(SEM)分析 34
3.2.3 膜厚量測儀(Alpha-step)分析 34
3.2.4 紫外光-可見光(UV-Visible)光譜分析 34
3.2.5 光激發螢光光譜(Photoluminescence, PL)分析 35
3.2.6 X-ray光電子能譜儀(XPS)分析 35
3.2.7 Mott-Schottky能帶結構分析 36
第4章 結果與討論 38
4.1 Cu2O電鍍電流密度之影響與最佳厚度調整 38
4.1.1 電鍍電流密度對結構及晶相之影響 38
4.1.2 電鍍電流密度對Cu2O薄膜光電性質之影響 41
4.1.3 電鍍Cu2O薄膜最佳厚度 43
4.1.4 Cu2O薄膜能帶結構分析 46
4.1.5 對電極電位之量測與氧氣還原反應(ORR) 48
4.2 Cu2Te電洞傳導層對Cu2O薄膜光電性質影響分析 49
4.2.1 濺鍍Cu2Te薄膜結構性質分析 49
4.2.2 Cu2O電鍍薄膜於Cu2Te上之晶相與形貌 51
4.2.3 Cu2Te對Cu2O薄膜光電性質影響 52
4.2.4 Cu2Te/Cu2O能帶結構與光電流提升機制 54
4.3 Cu2O薄膜中空位缺陷之分佈與影響 57
4.3.1 Cu2O薄膜XPS縱深分析 57
4.3.2 氧缺陷對Cu2O薄膜光電性質之影響 60
4.3.3 銅缺陷對Cu2O薄膜主要載子之影響 61
4.3.4 Cu2O薄膜光電性質與文獻之比較 62
第5章 結論 64
參考資料 65

[1] W. E. Council, World energy resources full report. 2016.
[2] C. M. White, R. R. Steeper, A. E. Lutz, The hydrogen-fueled internal combustion engine: a technical review. International Journal of Hydrogen Energy. 31, 1292-1305, 2006.
[3] N. Kannan, D. Vakeesan, Solar energy for future world: a review. Renewable and Sustainable Energy Reviews. 62, 1092-1105, 2016.
[4] S. N. Tackie, Performance evaluation of serhatkoy PV power plant, Master Thesis from The Graduate School of Applied Sciences of Near East University, Electrical and Electronic Engineering, 2015.
[5] M. Momirlan, T. N. Veziroglu, Current status of hydrogen energy. Renewable and Sustainable Energy Reviews. 6, 141-179, 2002.
[6] Y. Zhang, Y.-J. Heo, J.-W. Lee, J.-H. Lee, J. BajGai, K.-J. Lee, S.-J. Park, Photocatalytic hydrogen evolution via water splitting: a short review. Catalysts. 8, 655, 2018.
[7] O. Z. Sharaf, M. F. Orhan, An overview of fuel cell technology: fundamentals and applications. Renewable and Sustainable Energy Reviews. 32, 810-853, 2014.
[8] J. G. Speight, Gasification for synthetic fuel production. Woodhead Publishing. 1, 2015.
[9] E. Shoko, B. McLellan, A. L. Dicks, J. C. D. da Costa, Hydrogen from coal: production and utilisation technologies. International Journal of Coal Geology. 65, 213-222, 2006.
[10] P. Dias, A. Mendes, Hydrogen production from photoelectrochemical water splitting, Encyclopedia of Sustainability Science and Technology, 1-52, 2018.
[11] F. Biccari, Defects and doping in Cu2O, Ph.D. Thesis from Sapienza University of Rome, Philosophy in Physics, 2009.
[12] E. Ruiz, S. Alvarez, P. Alemany, R. A. Evarestov, Electronic structure and properties of Cu2O. Physical Review B. 56, 7189-7196, 1997.
[13] I. V. Bagal, N. R. Chodankar, M. A. Hassan, A. Waseem, M. A. Johar, D.-H. Kim, S.-W. Ryu, Cu2O as an emerging photocathode for solar water splitting: a status review. International Journal of Hydrogen Energy. 44, 21351-21378, 2019.
[14] Y. Yang, D. Xu, Q. Wu, P. Diao, Cu2O/CuO bilayered composite as a high-efficiency photocathode for photoelectrochemical hydrogen evolution reaction. Sci Rep. 6, 35158, 2016.
[15] A. Paracchino, V. Laporte, K. Sivula, M. Gratzel, E. Thimsen, Highly active oxide photocathode for photoelectrochemical water reduction. Nat Mater. 10, 456-461, 2011.
[16] Q.-B. Ma, J. P. Hofmann, A. Litke, E. J. M. Hensen, Cu2O photoelectrodes for solar water splitting: tuning photoelectrochemical performance by controlled faceting. Solar Energy Materials and Solar Cells. 141, 178-186, 2015.
[17] A. El Kasmi, Z.-Y. Tian, H. Vieker, A. Beyer, T. Chafik, Innovative CVD synthesis of Cu2O catalysts for CO oxidation. Applied Catalysis B: Environmental. 186, 10-18, 2016.
[18] T. Kosugi, S. Kaneko, Novel spray-pyrolysis deposition of cuprous oxide thin films. Journal of the American Ceramic Society. 81, 3117-3124, 1998.
[19] A. A. Dubale, C.-J. Pan, A. G. Tamirat, H.-M. Chen, W.-N. Su, C.-H. Chen, J. Rick, D. W. Ayele, B. A. Aragaw, J.-F. Lee, Y.-W. Yang, B.-J. Hwang, Heterostructured Cu2O/CuO decorated with nickel as a highly efficient photocathode for photoelectrochemical water reduction. Journal of Materials Chemistry A. 3, 12482-12499, 2015.
[20] H. Zhu, J. Zhang, C. Li, F. Pan, T. Wang, B. Huang, Cu2O thin films deposited by reactive direct current magnetron sputtering. Thin Solid Films. 517, 5700-5704, 2009.
[21] A. Fujishima, K. Honda, Electrochemical photolysis of water at a semiconductor electrode. Nature. 238, 37-38, 1972.
[22] M. Hara, T. Kondo, M. Komoda, S. Ikeda, J. N. Kondo, K. Domen, M. Hara, K. Shinohara, A. Tanaka, Cu2O as a photocatalyst for overall water splitting under visible light irradiation. Chemical Communications, 357-358, 1998.
[23] P. E. de Jongh, D. Vanmaekelbergh, J. J. Kelly, Cu2O: a catalyst for the photochemical decomposition of water? Chemical Communications, 1069-1070, 1999.
[24] C. A. N. Fernando, S. K. Wetthasinghe, Investigation of photoelectrochemical characteristics of n-type Cu2O films. Solar Energy Materials and Solar Cells. 63, 299-308, 2000.
[25] C. A. N. Fernando, T. M. W. J. Bandara, S. K. Wethasingha, H2 evolution from a photoelectrochemical cell with n-Cu2O photoelectrode under visible light irradiation. Solar Energy Materials and Solar Cells. 70, 121-129, 2001.
[26] T. Mahalingam, J. S. P. Chitra, G. Ravi, J. P. Chu, P. J. Sebastian, Characterization of pulse plated Cu2O thin films. Surface and Coatings Technology. 168, 111-114, 2003.
[27] T. Mahalingam, J. S. P. Chitra, J. P. Chu, P. J. Sebastian, Preparation and microstructural studies of electrodeposited Cu2O thin films. Materials Letters. 58, 1802-1807, 2004.
[28] T. Mahalingam, J. S. P. Chitra, J. P. Chu, S. Velumani, P. J. Sebastian, Structural and annealing studies of potentiostatically deposited Cu2O thin films. Solar Energy Materials and Solar Cells. 88, 209-216, 2005.
[29] T. Mahalingam, J. S. P. Chitra, J. P. Chu, H. Moon, H. J. Kwon, Y. D. Kim, Photoelectrochemical solar cell studies on electroplated cuprous oxide thin films. Journal of Materials Science: Materials in Electronics. 17, 519-523, 2006.
[30] L. Xu, X. Chen, Y. Wu, C. Chen, W. Li, W. Pan, Y. Wang, Solution-phase synthesis of single-crystal hollow Cu2O spheres with nanoholes. Nanotechnology. 17, 1501-1505, 2006.
[31] L. Ma, Y. Lin, Y. Wang, J. Li, E. Wang, M. Qiu, Y. Yu, Aligned 2-D nanosheet Cu2O film: oriented deposition on Cu foil and its photoelectrochemical property. The Journal of Physical Chemistry C. 112, 18916-18922, 2008.
[32] Y. Sui, Y. Zhang, W. Fu, H. Yang, Q. Zhao, P. Sun, D. Ma, M. Yuan, Y. Li, G. Zou, Low-temperature template-free synthesis of Cu2O hollow spheres. Journal of Crystal Growth. 311, 2285-2290, 2009.
[33] J. Luo, L. Steier, M. K. Son, M. Schreier, M. T. Mayer, M. Gratzel, Cu2O nanowire photocathodes for efficient and durable solar water splitting. Nano Lett. 16, 1848-1857, 2016.
[34] V. Figueiredo, E. Elangovan, G. Gonçalves, N. Franco, E. Alves, S. H. K. Park, R. Martins, E. Fortunato, Electrical, structural and optical characterization of copper oxide thin films as a function of post annealing temperature. physica status solidi (a). 206, 2143-2148, 2009.
[35] M. Wei, J. Huo, Preparation of Cu2O nanorods by a simple solvothermal method. Materials Chemistry and Physics. 121, 291-294, 2010.
[36] L. Gou, C. J. Murphy, Solution-phase synthesis of Cu2O nanocubes. Nano Letters. 3, 231-234, 2003.
[37] B. White, M. Yin, A. Hall, D. Le, S. Stolbov, T. Rahman, N. Turro, S. O'Brien, Complete CO oxidation over Cu2O nanoparticles supported on silica gel. Nano Letters. 6, 2095-2098, 2006.
[38] S. C. Ray, Preparation of copper oxide thin film by the sol–gel-like dip technique and study of their structural and optical properties. Solar Energy Materials and Solar Cells. 68, 307-312, 2001.
[39] C. Du, M. Xiao, Cu2O nanoparticles synthesis by microplasma. Sci Rep. 4, 7339, 2014.
[40] M. D. Susman, Y. Feldman, A. Vaskevich, I. Rubinstein, Chemical deposition of Cu2O nanocrystals with precise morphology control. ACS Nano. 8, 162-174, 2014.
[41] P. E. de Jongh, D. Vanmaekelbergh, J. J. Kelly, Cu2O:  electrodeposition and characterization. Chemistry of Materials. 11, 3512-3517, 1999.
[42] J. Azevedo, L. Steier, P. Dias, M. Stefik, C. T. Sousa, J. P. Araújo, A. Mendes, M. Graetzel, S. D. Tilley, On the stability enhancement of cuprous oxide water splitting photocathodes by low temperature steam annealing. Energy Environ. Sci. 7, 4044-4052, 2014.
[43] A. Paracchino, J. C. Brauer, J.-E. Moser, E. Thimsen, M. Graetzel, Synthesis and characterization of high-photoactivity electrodeposited Cu2O solar absorber by photoelectrochemistry and ultrafast spectroscopy. The Journal of Physical Chemistry C. 116, 7341-7350, 2012.
[44] M. G. Walter, E. L. Warren, J. R. McKone, S. W. Boettcher, Q. Mi, E. A. Santori, N. S. Lewis, Solar water splitting cells. Chemical Reviews. 110, 6446-6473, 2010.
[45] A. A. Dubale, A. G. Tamirat, H.-M. Chen, T. A. Berhe, C.-J. Pan, W.-N. Su, B.-J. Hwang, A highly stable CuS and CuS–Pt modified Cu2O/CuO heterostructure as an efficient photocathode for the hydrogen evolution reaction. Journal of Materials Chemistry A. 4, 2205-2216, 2016.
[46] H. Xu, S. Ouyang, L. Liu, P. Reunchan, N. Umezawa, J. Ye, Recent advances in TiO2-based photocatalysis. Journal of Materials Chemistry A. 2, 12642-12661, 2014.
[47] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, Y. Taga, Visible-light photocatalysis in nitrogen-doped titanium oxides. Science. 293, 269-271, 2001.
[48] J. Li, N. Wu, Semiconductor-based photocatalysts and photoelectrochemical cells for solar fuel generation: a review. Catalysis Science & Technology. 5, 1360-1384, 2015.
[49] A. Singh, S. Kumari, R. Shrivastav, S. Dass, V. Satsangi, Iron doped nanostructured TiO2 for photoelectrochemical generation of hydrogen. International Journal of Hydrogen Energy. 33, 5363-5368, 2008.
[50] K. M. H. Young, B. M. Klahr, O. Zandi, T. W. Hamann, Photocatalytic water oxidation with hematite electrodes. Catalysis Science & Technology. 3, 1660-1671, 2013.
[51] A. Murphy, P. Barnes, L. Randeniya, I. Plumb, I. Grey, M. Horne, J. Glasscock, Efficiency of solar water splitting using semiconductor electrodes. International Journal of Hydrogen Energy. 31, 1999-2017, 2006.
[52] T. W. Hamann, Splitting water with rust: hematite photoelectrochemistry. Dalton Trans. 41, 7830-7834, 2012.
[53] S. D. Tilley, M. Cornuz, K. Sivula, M. Gratzel, Light-induced water splitting with hematite: improved nanostructure and iridium oxide catalysis. Angew Chem Int Ed Engl. 49, 6405-6408, 2010.
[54] S. Chen, L.-W. Wang, Thermodynamic oxidation and reduction potentials of photocatalytic semiconductors in aqueous solution. Chemistry of Materials. 24, 3659-3666, 2012.
[55] J. Ebothé, Hole‐diffusion length and transport parameters of thin CdS films from a schottky barrier. Journal of Applied Physics. 59, 2076-2081, 1986.
[56] X. Zong, H. Yan, G. Wu, G. Ma, F. Wen, L. Wang, C. Li, Enhancement of photocatalytic H2 evolution on CdS by loading MoS2 as cocatalyst under visible light irradiation. Journal of the American Chemical Society. 130, 7176-7177, 2008.
[57] J. A. del Alamo, Nanometre-scale electronics with III-V compound semiconductors. Nature. 479, 317-323, 2011.
[58] M. H. Lee, K. Takei, J. Zhang, R. Kapadia, M. Zheng, Y. Z. Chen, J. Nah, T. S. Matthews, Y. L. Chueh, J. W. Ager, A. Javey, p-Type InP nanopillar photocathodes for efficient solar-driven hydrogen production. Angew Chem Int Ed Engl. 51, 10760-10764, 2012.
[59] O. Khaselev, A. Bansal, J. A. Turner, High-efficiency integrated multijunction photovoltaic/electrolysis systems for hydrogen production. International Journal of Hydrogen Energy. 26, 127-132, 2001.
[60] C.-C. Hu, J.-N. Nian, H. Teng, Electrodeposited p-type Cu2O as photocatalyst for H2 evolution from water reduction in the presence of WO3. Solar Energy Materials and Solar Cells. 92, 1071-1076, 2008.
[61] L. Pan, J. H. Kim, M. T. Mayer, M.-K. Son, A. Ummadisingu, J. S. Lee, A. Hagfeldt, J. Luo, M. Grätzel, Boosting the performance of Cu2O photocathodes for unassisted solar water splitting devices. Nature Catalysis. 1, 412-420, 2018.
[62] T. G. Kim, H.-b. Oh, H. Ryu, W.-J. Lee, The study of post annealing effect on Cu2O thin-films by electrochemical deposition for photoelectrochemical applications. Journal of Alloys and Compounds. 612, 74-79, 2014.
[63] Z. Zhang, R. Dua, L. Zhang, H. Zhu, H. Zhang, P. Wang, Carbon-layer-protected cuprous oxide nanowire arrays for efficient water reduction. ACS Nano. 7, 1709-1717, 2013.
[64] J. L. Sculfort, D. Guyomard, M. Herlem, Photoelectrochemical characterization of the p-Cu2O-non aqueous electrolyte junction. Electrochimica Acta. 29, 459-465, 1984.
[65] Y. Yang, J. Han, X. Ning, J. Su, J. Shi, W. Cao, W. Xu, Photoelectrochemical stability improvement of cuprous oxide (Cu2O) thin films in aqueous solution. International Journal of Energy Research. 40, 112-123, 2016.
[66] C. H. Chuang, P. R. Brown, V. Bulovic, M. G. Bawendi, Improved performance and stability in quantum dot solar cells through band alignment engineering. Nat Mater. 13, 796-801, 2014.
[67] J. P. Correa Baena, L. Steier, W. Tress, M. Saliba, S. Neutzner, T. Matsui, F. Giordano, T. J. Jacobsson, A. R. Srimath Kandada, S. M. Zakeeruddin, A. Petrozza, A. Abate, M. K. Nazeeruddin, M. Grätzel, A. Hagfeldt, Highly efficient planar perovskite solar cells through band alignment engineering. Energy & Environmental Science. 8, 2928-2934, 2015.
[68] C. Gong, H. Zhang, W. Wang, L. Colombo, R. M. Wallace, K. Cho, Band alignment of two-dimensional transition metal dichalcogenides: application in tunnel field effect transistors. Applied Physics Letters. 103, 053513, 2013.
[69] A. Klein, Energy band alignment in chalcogenide thin film solar cells from photoelectron spectroscopy. J Phys Condens Matter. 27, 134201, 2015.
[70] A. Klein, D. J. Green, Transparent conducting oxides: electronic structure-property relationship from photoelectron spectroscopy with in-situ sample preparation. Journal of the American Ceramic Society. 96, 331-345, 2012.
[71] H. Hasegawa, Fermi level pinning and schottky barrier height control at metal-semiconductor interfaces of InP and related materials. Japanese Journal of Applied Physics. 38, 1098-1102, 1999.
[72] Z. Zheng, B. Huang, Z. Wang, M. Guo, X. Qin, X. Zhang, P. Wang, Y. Dai, Crystal faces of Cu2O and their stabilities in photocatalytic reactions. The Journal of Physical Chemistry C. 113, 14448-14453, 2009.
[73] C. S. Tan, S. C. Hsu, W. H. Ke, L. J. Chen, M. H. Huang, Facet-dependent electrical conductivity properties of Cu2O crystals. Nano Lett. 15, 2155-2160, 2015.
[74] H. J. Queisser, E. E. Haller, Defects in semiconductors: some fatal, some vital. Science. 281, 945, 1998.
[75] K. Seeger, Semiconductor physics. Springer-Verlag Berlin Heidelberg. 9, 2004.
[76] A. Sarkar, G. G. Khan, The formation and detection techniques of oxygen vacancies in titanium oxide-based nanostructures. Nanoscale. 11, 3414-3444, 2019.
[77] Y. Lv, Y. Zhu, Y. Zhu, Enhanced photocatalytic performance for the BiPO4–x nanorod induced by surface oxygen vacancy. The Journal of Physical Chemistry C. 117, 18520-18528, 2013.
[78] B. Wang, X. Wang, L. Lu, C. Zhou, Z. Xin, J. Wang, X.-k. Ke, G. Sheng, S. Yan, Z. Zou, Oxygen-vacancy-activated CO2 splitting over amorphous oxide semiconductor photocatalyst. ACS Catalysis. 8, 516-525, 2017.
[79] M. Singh, D. Jampaiah, A. E. Kandjani, Y. M. Sabri, E. Della Gaspera, P. Reineck, M. Judd, J. Langley, N. Cox, J. van Embden, E. L. H. Mayes, B. C. Gibson, S. K. Bhargava, R. Ramanathan, V. Bansal, Oxygen-deficient photostable Cu2O for enhanced visible light photocatalytic activity. Nanoscale. 10, 6039-6050, 2018.
[80] K. Gelderman, L. Lee, S. W. Donne, Flat-band potential of a semiconductor: using the Mott–Schottky equation. Journal of Chemical Education. 84, 685-688, 2007.
[81] G. Debernardi, C. Carlesi, Chemical-electrochemical approaches to the study passivation of chalcopyrite. Mineral Processing and Extractive Metallurgy Review. 34, 10-41, 2013.
[82] D. Hu, P. Diao, D. Xu, M. Xia, Y. Gu, Q. Wu, C. Li, S. Yang, Copper(II) tungstate nanoflake array films: sacrificial template synthesis, hydrogen treatment, and their application as photoanodes in solar water splitting. Nanoscale. 8, 5892-5901, 2016.
[83] V. K. K., A. R. B. V., Chemically modified biopolymer as an eco-friendly corrosion inhibitor for mild steel in a neutral chloride environment. New Journal of Chemistry. 41, 6278-6289, 2017.
[84] S. Shyamal, A. Maity, A. K. Satpati, C. Bhattacharya, Development of Cu2O thin films under the influence of electrochemical impedance: applications in improved photoelectrochemical water reduction. Electrochimica Acta. 308, 384-391, 2019.
[85] D. Cao, N. Nasori, Z. Wang, L. Wen, R. Xu, Y. Mi, Y. Lei, Facile surface treatment on Cu2O photocathodes for enhancing the photoelectrochemical response. Applied Catalysis B: Environmental. 198, 398-403, 2016.
[86] H. Wang, P. Zuo, A. Wang, S. Zhang, C. Mao, J. Song, H. Niu, B. Jin, Y. Tian, Facile synthesis and electrochemical property of Cu2Te nanorods. Journal of Alloys and Compounds. 581, 816-820, 2013.
[87] H. Solache-Carranco, G. Juárez-Díaz, A. Esparza-García, M. Briseño-García, M. Galván-Arellano, J. Martínez-Juárez, G. Romero-Paredes, R. Peña-Sierra, Photoluminescence and X-ray diffraction studies on Cu2O. Journal of Luminescence. 129, 1483-1487, 2009.
[88] W. He, H. Zhang, Y. Zhang, M. Liu, X. Zhang, F. Yang, Electrodeposition and characterization of CuTe and Cu2Te thin films. Journal of Nanomaterials. 2015, 1-5, 2015.
[89] C.-C. Lin, W.-F. Lee, M.-Y. Lu, S.-Y. Chen, M.-H. Hung, T.-C. Chan, H.-W. Tsai, Y.-L. Chueh, L.-J. Chen, Low temperature synthesis of copper telluride nanostructures: phase formation, growth, and electrical transport properties. Journal of Materials Chemistry. 22, 7098-7103, 2012.
[90] M. A. Matin, M. U. Tomal, A. M. Robin. Copper telluride as a nobel BSF material for high performance ultra thin CdTe PV cell. International Conference on Informatics, Electronics and Vision (ICIEV), (2013).
[91] S. N. Mostafa, S. R. Selim, S. A. Soliman, E. G. Gadalla, Electrochemical investigations of a copper—tellurium system and determination of the band gap for α-Cu2Te. Electrochimica Acta. 38, 1699-1703, 1993.
[92] C. Han, Y. Bai, Q. Sun, S. Zhang, Z. Li, L. Wang, S. Dou, Ambient aqueous growth of Cu2Te nanostructures with excellent electrocatalytic activity toward sulfide redox shuttles. Adv Sci (Weinh). 3, 1500350, 2016.
[93] W. Wang, D. Wu, Q. Zhang, L. Wang, M. Tao, pH-dependence of conduction type in cuprous oxide synthesized from solution. Journal of Applied Physics. 107, 123717, 2010.