High efficiency polycrystalline Cu(In,Ga)Se2-based solar cells

Electroluminescence analysis of high efficiency Cu(In,Ga)Se2 solar cells

“…͑ii͒ All spectra are considerably broader than one would expect from a direct semiconductor. We propose that for low temperatures this broadening is a result of a DAP transition, broadened due to potential fluctuations, [25][26][27][28] whereas at higher temperatures the broadening of a BB transition is due to lateral band gap fluctuations 16,[20][21][22][23][24][25][26][27][28][29] …”

“…The samples investigated were high efficiency Cu͑In, Ga͒Se 2 solar cells, fabricated by a three stage process 21 that enables efficiencies Ͼ 19% ͑on a cell area of 0.5 cm 2 ͒ 22 to be achieved. After evaporation of the 1.5 m thick Mo back contact on a glass substrate, the first stage of absorber deposition consists of the evaporation of In, Se, and Ga at a substrate temperature T = 400°C.…”

Development of thin‐film Cu(In,Ga)Se2 and CdTe solar cells

“…[61][62][63] An 'inverse' two-stage process starts with a precursor layer that is more Cu-poor than the finished film. 64,65 The so-called three-stage process, introduced by NREL, 66 is obtained by starting the deposition with an (In,Ga) x Se y precursor, followed by the co-deposition of Cu and Se until Cu-rich overall composition is reached, and finally the overall Cu concentration is readjusted by subsequent deposition of In, Ga and Se. 66 This method leads, up to now, to the most efficient solar cells.…”

What is Happening with Regards to Thin-Film Photovoltaics?

“…The record cells were mostly made by a process call co-evaporation. Typically, this process has multiple "stages" involved, finishing devices with a Cu-poor (or In-rich) surface layer (Gabor et al 1994). This process has also been adopted for CIGS module manufacturing.…”