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

• Published in: Nano energy Vol. 10; pp. 28 - 36
• Main Authors: Wu, Tsung-Ta, Huang, Jyun-Hong, Hu, Fan, Chang, Chia-ho, Liu, Wen-Long, Wang, Tsang-Hsiu, Shen, Chang-Hong, Shieh, Jia-Min, Chueh, Yu-Lun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2014
• Subjects: Cu(InGa)Se2; Ga depth profile; Pre-annealing; Selenization; Stacked precursor; Stacked precursor; Pre-annealing; Ga depth profile; Selenization; Cu(InGa)Se2
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2014.07.018

Modified stacking sequence of precursors and pre-annealing process on Se vapor at low temperature were applied to Cu(In,Ga)Se2 (CIGS) solar. The remarkable improvement of efficiency (5.53–10.10% and further 11.04%) and open circuit voltage (0.41V–0.53V and further 0.56V) comes from a compact, smooth microstructure, and modified depth profile of Ga with suitable thickness of CuGa multi-stacking layers in the top of precursors as well as surface bandgap enhancement via pre-annealing process without Se vapor followed by a specific non-toxic hydrogen-assisted solid Se vapor selenization process. The effects of microstructural, compositional and electrical characteristics of Ga distribution including accumulation and interdiffusion were examined in detail. Finally, a large-area (40×30cm2) CIGS solar cell efficiency with improved open circuit voltage (VOC) and fill factor (FF) of 36% and 14% has been demonstrated, yielding a promising efficiency of ~11.04%. [Display omitted] •Ga distribution control as well as band gap engineering are achieved.•Stacking sequences modification and novel selenization profile design is verified.•The pre-annealing & non-toxic HASVS method meet the solution-based process trend.•Large area (30×40 cm2) and high efficiency (11%) CIGS solar panels are exhibited.