An evaluation for CIGS based thin-film solar cells development

Document Type : Review Article


Department of Physics, Naragh Branch, Islamic Azad University, Naragh, Iran


This review summarizes the current status of chalcopyrite CIGS thin film solar cell technology with a focus on recent advancements and emerging concepts intended for higher efficiency and novel applications. The recent developments and trends of research in labs and industrial achievements communicated within the last years are reviewed and the major developments linked to alkali post deposition treatment and composition grading in CIGS, surface passivation, buffer and transparent contact layers are emphasized. In recent years, a lot of efforts have been initiated to develop low-cost thin-film solar cells, which are alternatives to high-cost silicon (Si) solar cells. Copper Indium Gallium Selenide (CIGS) based solar cells have become one of the most promising candidates among the thin film technologies for solar power generation. The current record efficiency of CIGS has reached 22.6%, which exceeds the current multi crystalline Si record efficiency (21.9%). However, material properties and efficiency on small area devices are crucial aspects to be considered before manufacturing into large scale. Chalcopyrite-based solar cells were first developed using CuInSe_2 absorber material, but it was quickly become dependent on the [Ga⁄((In+Ga)]) ratio.


Article Title [فارسی]

ارزیابی توسعه سلول های خورشیدی لایه نازک مبتنی بر CIGS

Author [فارسی]

  • مجتبی جمعیتی

گروه فیزیک، واحد نراق، دانشگاه آزاد اسلامی، نراق، ایران

Abstract [فارسی]

این مطالعه وضعیت فعلی فناوری سلول های خورشیدی لایه نازک کالکوپیریت CIGS را با تمرکز بر پیشرفت های اخیر و مفاهیم نوظهور در نظر گرفته شده برای کارایی بالاتر و کاربردهای جدید خلاصه می کند. پیشرفت‌ها و روندهای اخیر تحقیقات در آزمایشگاه‌ها و دستاوردهای صنعتی که در سال‌های گذشته گزارش گردیده، مورد بررسی قرار گرفته است و پیشرفت‌های عمدتاً مرتبط با فلزات قلیایی و ترکیبات متنوع سلول‌های مبتنی بر  CIGS، غیرفعال‌سازی سطح، لایه بافر و لایه‌های تماس شفاف مورد تاکید قرار گرفته‌اند. در سال‌های اخیر، تلاش‌های زیادی برای توسعه سلول‌های خورشیدی لایه نازک کم‌هزینه، که جایگزین سلول‌های خورشیدی سیلیکونی (Si) پرهزینه هستند، آغاز شده است. سلول های خورشیدی مبتنی بر گالیوم سلنید مس ایندیم (CIGS) به یکی از امیدوارکننده ترین کاندیدها در میان فناوری های لایه نازک برای تولید انرژی خورشیدی تبدیل شده اند. ماکزیمم بازده فعلی سلول‌های CIGS به 6/22٪ رسیده است که از ماکزیمم بازده سلول‌های چند بلوری سیلیکون (9/21٪) فراتر رفته است. با این حال، خواص و کارایی مواد در دستگاه‌های با مساحت کوچک، جنبه‌های مهمی هستند که باید قبل از تولید در مقیاس بزرگ در نظر گرفته شوند. سلول های خورشیدی مبتنی بر کالکوپیریت ابتدا با استفاده از مواد جاذب  ساخته شدند، اما به سرعت به نسبت [Ga⁄((In+Ga)]) وابسته شدند.

[1] M. Jamiati, B. Khoshnevisana, M. Mohammadib, "Second- and third-order elastic constants of kesterite CZTS and its electronic and optical properties under various strain rates." Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 40(8) (2018) 977.
[2] A. Kowsar, S. F. U. Farhad, "High Efficiency Four Junction III-V Bismide Concentrator Solar Cell: Design, Theory, and Simulation." International Journal of Renewable Energy Research (IJRER), 8 (2018) 17621769.
 [3] D. Jeyakumar Ramanujama, et al., "Flexible CIGS, CdTe and a-Si:H based thin film solar cells: A review." Progress in Materials Science, 110 (2020) 100619.
[4] R. Light trapping in thin silicon solar cells: A review on fundamentals and technologies, 7 (2021) 3440.
[5] C. Romain, et al., "Advanced alkali treatments for high-efficiency Cu(In, Ga)Se2 solar cells on flexible substrates." Adv. Energy Mater, 9 (2019) 1900408.             
[6] A. Bosio, S. Pasini, N. Romeo. Advances in Thin Films for Photovoltaic, 10(4) (2020) 344.            
[7] Y. Wu, et al., "Synthesis and photovoltaic application of copper (I) sulfide nanocrystals," Nano letters, 8 (2008) 2551.
[8] M. A. Green, et al., "Solar cell efficiency tables (version 52)." Progress in Photovoltaics: Research and Applications, 26 (2018) 427.
[9] A. Kowsar, et al., " Progress in Major Thin-film Solar Cells: Growth Technologies, Layer Materials and Efficiencies." INTERNATIONAL JOURNAL of RENEWABLE ENERGY RESEARCH, 9(2) (2019) 579.
[10] U. Rau, H. W. Schock, "Cu (In, Ga) Se 2 solar cells," in Clean Electricity from Photovoltaics, ed: World Scientific, (2001) 277-345.
[11] S. Wagner, J. Shay, P. Migliorato, H. Kasper, "CuInSe2/CdS heterojunction photovoltaic detectors." Applied Physics Letters, 25 (1974) 434.
[12] L. L. Kazmerski, F. R. White, G. K. Morgan, “Thin-film CuInSe2/CdS heterojunction solar cells.” Applied Physics Letters, 29(4) (1976) 268.
[13]R. Mickelsen, W. Chen, "Development of a 9.4% efficient thin-film CuInSe2/CdS solar cell." in 15th photovoltaic specialists conference, (1981) 800.
[14]J. Tuttle, et al., "Accelerated publication 17.1% efficient Cu (In, Ga) Se2- based thin- film solar cell." Progress in Photovoltaics: Research and Applications, 3 (1995) 235.
[15]M. A. Contreras, et al., "Progress toward 20% efficiency in Cu (In, Ga) Se2 polycrystalline thin- film solar cells." Progress in Photovoltaics: Research and applications, 7 (1999) 311.
[16] I. Repins, et al., "Characterization of 19.9%efficient CIGS absorbers," in Photovoltaic Specialists Conference, 2008. PVSC'08. 33rd IEEE, (2008) 1-6.
[17]T. Satoh, et al., "Cigs solar cells on flexible stainless steel substrates," in Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE, (2000), 567-570.
[18] R. Wuerz, et al., "CIGS thin-film solar cells on steel substrates." Thin Solid Films, 517 (2003) 24152418.
[19]C. Shi, et al., "Cu (In, Ga) Se2 solar cells on stainless-steel substrates covered with ZnO diffusion barriers." Solar Energy Materials and Solar Cells, 93 (2009) 654.
[20]B. M. Başol, et al., "Flexible and light weight copper indium diselenide solar cells on polyimide substrates," Solar Energy Materials and Solar Cells, 43 (1996) 9398.
[21]M. Feli, F. Parandin, "A Numerical Optimization of an Efficient Double Junction InGaN/CIGS Solar Cell." J. Electr. Comput. Eng. Innovations, 6(1) (2018) 53.
[22] H. Zachmann, et al., "Characterisation of Cu(In, Ga)Se2-based thin film solar cells on polyimide." Thin Solid Films, 517 (2009) 2209.
[23]B. M. Başol, et al., "Copper indium diselenide thin film solar cells fabricated on flexible foil substrates." Solar Energy Materials and Solar Cells, 29 (1993) 163.
[24] M. A. Green, et al., "Solar cell efficiency tables (version 42)." Progress in Photovoltaics: Research and Applications, 5 (2013) 827.
[25] M. Powalla, et al., "Advances in Cost-Efficient Thin-Film Photovoltaics Based on Cu(In,Ga)Se2." Engineering, 3 (2017) 445.
[26] J. Parkes, R. D. Tomlinson, M. J. Hampshire, " Crystal data for CuInSe2." J. Appl. Crystallogr., 6 (1973) 414.
[27] S. C. Abrahams, J. L. Bernstein, "Piezoelectric nonlinear optic CuGaSe2 and CdGeAs2: Crystal structure, chalcopyrite microhardness, and sublattice distortion." J. Chem. Phys., 61 (1974) 1140.
[28] S. Chen, X. G. Gong, S. H. Wei, "Band-structure anomalies of the chalcopyrite semiconductors CuGaX2 versus AgGaX2 (X=S and Se) and their alloys." Phys. Rev. B, 75 (2007) 205209.
[29] C. D. R. Ludwig, T. Gruhn, C. Felser, " Indium-Gallium Segregation in CuInxGa1-xSe2: An Ab Initio-Based Monte Carlo Study." Phys. Rev. Lett., 105 (2010) 025702.
[30] J. Osuntokun, P. A. Ajibade, "Structural and Thermal Studies of ZnS and CdS Nanoparticles in Polymer Matrices." Journal of Nanomaterials, 2016 (2016) 3296071.
[31] J. L. Shay, H. M. Kasper, L. M. Schivone, "Electronic Structure of AgInSe2 and CuInSe2." Phys. Rev. B, 7 (1973) 4485.
[32] J. L. Shay and H. M. Kasper, " Direct Observation of Cu-d Levels in I-III-VI2 Compounds." Phys. Rev. Lett., 29 (1972) 1162.
[33] U. Rau, K. Taretto, S. Siebentritt, "Grain boundaries in Cu(In, Ga)(Se, S)2 thin-film solar cells." Appl. Phys. A Mater. Sci. Process., 96 (2009) 221.
[34] P. Palacios, et al., "Thermodynamics of the Formation of Ti- and Cr-doped CuGaS2 Intermediate-band Photovoltaic Materials." J. Phys. Chem. C, 112 (2008) 9525.
[35] T. D. Lee, A. Ebong, “Thin film solar technologies: a review.” in 2015 12th International Conference on High-capacity Optical Networks and Enabling/Emerging Technologies (HONET), Islamabad, Pakistan, (2015) 1.
[36] Y. C. Wang, H. P. D. Shieh, “Double-graded bandgap in Cu(In,Ga)Se2 thin film solar cells by low toxicity selenization process.” Applied Physics Letters, 105(7) (2014) 073901.
[37] J. Ramanujam, U. P. Singh, “Copper indium gallium selenide based solar cells – a review.” Energy & Environmental Science, 10(6) (2017) 1306.
[38] J.E. Jaffe, A. Zunger, “Electronic structure of the ternary chalcopyrite semiconductors CuAlS2, CuGaS2, CuInS2, CuAlSe2, CuGaSe2, and CuInSe2." Phys. Rev. B, 28 (1983) 5822.
[39] S. H. Weiand, L. G. Ferreira, A. Zunger, "First-principles calculation of the order-disorder transition in chalcopyrite semiconductors." Phys. Rev. B, 45 (1992) 2533.
[40] S. H. Weiand, A. Zunger, " Band offsets at the CdS/CuInSe2 heterojunction." Appl. Phys. Lett., 63 (1993) 2549.
[41] S. H. Weiand, A. Zunger, "Band offsets and optical bowings of chalcopyrites and Zn‐based II‐VI alloys." J. Appl. Phys., 78 (1995) 3846.
[42] M. Gloeckler, J. R. Sites, "Guidelines for Optimization of the Absorber Layer Energy Gap for High Efficiency Cu(In,Ga)Se2 Solar Cells." J. of Phys. and Chem. of Solids, 66 (2005) 1891.
[43] S. B. Zhang, S. H. Weiand, A. Zunger, "Stabilization of Ternary Compounds via Ordered Arrays of Defect Pairs." Phys. Rev. Lett., 78 (1997) 4059.
[44] S. B. Zhang, S. H. Weiand, A. Zunger, H. Katayama-Yoshida, " Defect physics of the CuInSe2 chalcopyrite semiconductor." Phys. Rev. B, 57 (1998) 9642.
[45] S. H. Weiand, S. B. Zhang, and A. Zunger, " Effects of Na on the electrical and structural properties of CuInSe2." J. Appl. Phys., 85 (1999) 7214.
[46] S. H. Weiand, S.B. Zhang, and A. Zunger, "Effects of Ga addition to CuInSe2 on its electronic, structural, and defect properties." Appl. Phys. Lett., 72 (1998) 3199.
[47] C. H. Huang, "Effects of Ga content on Cu(In,Ga)Se2 solar cells studied by numerical modeling." J. of Phys. and Chem. of Solids, 69 (2008) 330.
[48] Z. A. Shukri, et al., "Preliminary photovoltaic cells with single crystal CIS substrates." Solar Energ. Mater. and Solar Cells, 37 (1995) 395.
[49] M. Gloeckler, J. R. Sites, W. K. Metzger, "Grain-boundary recombination in Cu(In,Ga)Se2 solar cells." J. Appl. Phys, 98 (2005) 113704.
[50] J. M. Raulot, C. Domain, J.F. Guillemoles, "Ab initio investigation of potential indium and gallium free chalcopyrite compounds for photovoltaic application." J. of Phys. and Chem. of Solids, 66(11) (2005) 2019.
[51] W. N. Shafarman, S. Siebentritt and L. Stolt, Handbook of Photovoltaic Science and Engineering, Wiley, New York, 2011.
[52] P. Jackson, et al., "High quality baseline for high efficiency, Cu(In1−x,Gax)Se2 solar cells." Progress in Photovoltaics: Research and Applications.,15 (2007) 507.
[53] H. Zhao, C. Persson, "Optical properties of Cu(In,Ga)Se2 and Cu2ZnSn(S,Se)4." Thin Solid Films, 519 (2011) 7508.
[54] M. Chandramohan, S.Velumani, T. Venkatachalam, "Band structure calculations of Cu(In1−xGax)Se2." J. Materials Science and Engineering B, 174 (2010) 200.
[55] A. Bouich, et al., " Deposit on different back contacts: to high‑quality  thin films for photovoltaic application." Journal of Materials Science: Materials in Electronics, 30(23) (2019) 20832.
[56] C. Persson, "Electronic and optical properties of Cu2ZnSnS4 and Cu2ZnSnSe4." J. Appl. Phys., 107 (2010) 053710.
[57] T. Kawashima, et al., "Optical constants of CuGaSe2 and CuInSe2." J. Appl. Phys., 84 (1998) 5202.
[58] N. N. Syrbu, et al., "Lattice vibrations in  crystals." J. Phys. B, 229 (1997) 199.
[59]F. Ghavami, A. Salehi, "High-efficiency CIGS solar cell by optimization of doping concentration thickness and energy band gap." Modern Physics Letters B, 34(4) (2020) 2050053.
[60]P. Reinhard, et al., "Review of Progress Toward 20% Efficiency Flexible CIGS Solar Cells and Manufacturing Issues of Solar Modules." IEEE Journal of Photovoltaics, 3(1) (2013) 572.
[61]W. N. Shafarman, S. Siebentritt, L. Stolt, " Cu(InGa)Se2 solar cells in: Luque A, Hegedus S," Handbook of photovoltaic science and engineering, England: John Wiley & Sons Ltd;  pp. 546-599, 2010.
[62]        R. Scheer, H. W. Schock, " Chalcogenide Photovoltaics: Physics, Technologies and Thin Film Devices." John Wiley & Sons Ltd; pp. 154-172, 2011.
[63]A. Chirilă, et al., " Potassium-induced surface modification of  thin films for high efficiency solar cells." Nature Materials, 12(12) (2013) 1107.
[64]T. Feurer, et al., "Progress in Thin Film CIGS Photovoltaics – R&D, Manufacturing and Applications." Progress in Photovoltaics, 25(7) (2017) 645.
[65]K. Kushiya, " CIS-based thin-film PV technology in solar frontier K.K " Solar Energy Materials and Solar Cells, 122 (2014) 309.
[66]" Solar Frontier Achieves World Record Thin-Film Solar Cell Efficiency:  22.3%." Solar Frontier company webpageDecember 8, 2015Accesed April 25, 2016.
[67] S. Duchemin et al., in: Photovoltaic Solar Energy (Proc.8th European Conf., Florence, Italy, (1988), P. 1038- 1042.
[68] T. Nakada et al., in:Photovoltaic Energy Conversion (IEEE First World Conf., Hawaii, USA, 1994), 95- 98.
[69] M. A. Green, "The path to 25% silicon solar cell efficiency: History of silicon cell evolution." Progr. in Photovolt.: Research and Applications, 17 (2009) 183.
[70] T. Nakada, T.Mise, "High-efficiency superstrate type cigs thin film solar cells with graded band gap absorber layers.” inProceedings of the 17th European Photovoltaic Solar Energy Conference, pp. 1027–1030, Munich, Germany, 2001.
[71] F. Dimroth, et al., "Wafer bonded four-junction GaInP/GaAs//GaInAsP/GaInAs concentrator solar cells with 44.7% efficiency." Progr. in Photovolt.: Research and Applications, 22 (2014) 277.
[72] S. Keshmiri, H.S. Sharbati, "Model for increased efficiency of CIGS solar cells by a stepped distribution of carrier density and Ga in the absorber layer." Science China Phys. Mech. and Astronomy, 56(8) (2013) 1533.
[73] P. Jackson, et al., "Compositional investigation of potassium doped Cu(In,Ga)Se2 solar cells with efficiencies up to 20.8%." J. Physica Status Solidi (RRL)-Rapid Research Lett., 8 (2014) 219.
[74] H. Ullah, B. Mari, H. N. Cui, "Investigation on the Effect of Gallium on the Efficiency of CIGS Solar Cells through Dedicated Software." J. Applied Mech. and Mater.,448 (2014) 1497.
[75] M. Tawheed Kibria, et al., "A Review: Comparative studies on different generation solar cells technology." Proceedings of 5th International Conference on Environmental Aspects of Bangladesh [ICEAB 2014].
[76] J. Hedstrom, et al., " Zno/Cds/Cu(in,Ga)Se2 Thin-Film Solar-Cells with Improved Perfornance." Conference Record of the Twenty Third Ieee Photovoltaic Specialists, (1993) 364.
[77] D. Rudmann, et al., "Sodium incorporation strategies for CIGS growth at different temperatures." Thin Solid Films, 480 (2005) 55.
[78] D. Rudmann, et al., " Efficiency enhancement of Cu(In,Ga)Se₂ solar cells due to post-deposition Na incorporation." Applied Physics Letters, 84(7) (2004) 1129.
[79] P. Reinhard, et al., " Features of KF and NaF Postdeposition Treatments of Cu(In,Ga)Se2 Absorbers for High Efficiency Thin Film Solar Cells." Chemistry of Materials, 27(16) (2015) 5755.
[80] L. M. Mansfield, et al., " Enhanced Performance in Cu(In,Ga)Se Solar Cells Fabricated by the Two-Step Selenization Process With a Potassium Fluoride Postdeposition Treatment." IEEE Journal of Photovoltaics, 4(6) (2014) 1650.
[81] H. Ullah, B. Marí, L. M. Sánchez Ruiz, " Comparative analysis of CIGS thin film and Multilayer Solar cells." Proc.Int. Conf. Engineering Education and research, Riga, Latviya, ICEE/ICIT 2014, (2014) 103.