Modification of deposition process for Cu(In, Ga)Se₂ thin film solar cells on polyimide substrate at low temperature

Abstract

We fabricate polycrystalline Cu(In, Ga)Se₂ (CIGS) film solar cells on polyimide (PI) substrate at temperature of 450 °C with single-stage process, and obtain a poor crystallization of CIGS films with several secondary phases in it. For improving it further, the two-stage process is adopted instead of the single-stage one. An extra Cu-rich CIGS layer with the thickness from 100 nm to 200 nm is grown on the substrate, and then another Cu-poor CIGS film with thickness of 1.5–2.0 μm is deposited on it. With the modification of the evaporation process, the grain size of absorber layer is increased, and the additional secondary phases almost disappear. Accordingly, the overall device performance is improved, and the conversion efficiency is enhanced by about 20%.

Keywords

Solar Cell / External Quantum Efficiency / Absorber Layer / Thin Film Solar Cell / Polyimide Substrate

References

[1] JacksonP, HariskosD, LotterE, PaetelS, WuerzR, MennerR, WischmannW, PowallaM. Progress in Photovoltaics: Research and Applications, 2011, 19: 894

[2] TuttleJ R, SzalajA, KeaneJ A. 15.2% AMO/1433 W/kg Thin Film CIGS Solar Cell for Space ApplicationsConference Record of the 28th IEEE Photovoltaic Specialists Conference, 2000, 1042

[3] ChirilaA, BuechelerS, PianezziF, BloeschP, GretenerC, UhlA R, FellaC, KranzL, PerrenoudJ, SeyrlingS, VermaR, NishiwakiS, RomanyukY E, BilgerG, TiwariA N. Nature Materials, 2011, 10: 857

[4] LiB-y, ZhangY, LiuW, SunY. Optoelectronics Letters, 2012, 8: 348

[5] WangH, ZhangY, KouX L, CaiY A, LiuW, YuT, PangJ B, LiC J, SunY. Semicond. Sci. Technol., 2010, 25: 055007

[6] KessleraF, RudmannD. Solar Energy, 2004, 77: 685

[7] JiangW-l, HeQ, LiuW, YuT, LiuF-f, PangJ-b, LiF-y, LiC-j, SunY. Journal of Optoelectronics·Laser, 2010, 21: 1657

[8] RockettA, BrittJ S, GillespieT, MarshallC, JassimM M A, HasoonF, MatsonR, BasolB. Thin Solid Films, 2000, 372: 212

[9] RudmannD, BilgerG, KaelinM, HaugF J, ZoggH, TiwariA N. Thin Solid Films, 2003, 431: 37

[10] ZhangL. Researches on Depositing CIGS Thin Films at Low Substrate Temperature and the Performance of CIGS Solar Cells with Polyimide Substrate, 2008, Tianjin, China, Nankai University

[11] ScholdstromJ, KesslerJ, EdoffM. Thin Solid Films, 2005, 480: 61

[12] SeyrlingS, ChirilaA, GuttlerD, BloschP, PianezziF, VermaR, BuchelerS, NishiwakiS, RomanyukY E, RossbachP, TiwariA N. Solar Energy Materials & Solor Cells, 2011, 95: 1477

[13] GaborA M, TuttleJ R, BodeM H, FranzA, TennantA L, ContreasM A, NoufiR, JensenD G, HermannA M. Materials and Solar Cells, 1996, 41-42: 247

[14] KodigalaS R. Thin Films and Nanostructures, 2010, 35: 123

[15] XuC M, XuX L, XuJ, YangX J, ZuoJ, KongN, HuangW H, LiuH T. Semicond. Sci. Technol., 2004, 19: 1201

[16] CaballeroR, KaufmannC, EfimovaA V, RissomT, HoffmannV, SchockH W. Investigation of Cu(In, Ga)Se₂ Thin-film Formation during the Multi-stage Co-evaporation ProcessProp. Photovolt: Res. Appl., 2012, 1233

[17] CaballeroR, Izquierdo-RocaV, FontaneX, KaufmannC A, Alvarez-GarciaJ, EickeA, Calvo-BarrioL, Perez-RodriguzeA, SchockH K, MoranteJ R. Acta Materialia, 2010, 58: 3468

[18] KesslerJ, ChityuttakanC, LuJ, ScholdstromJ, StoltL. Prog. Photovolt: Res. Appl., 2003, 11: 319

[19] KesslerJ, ChityuttakanC, ScholdstromJ, StoltL. Thin Solid Films, 2003, 431-432: 1

[20] BarreauN, PainchaudT, Couzinie-DevyF, ArzelL, KesslerJ. Acta Materialia, 2010, 58: 5572