Title :
Processing of Cu(In,Ga)Se2 solar cells from electrodeposited precursors
Author :
Dobson, Kevin D. ; Birkmire, Robert W.
Author_Institution :
Inst. of Energy Conversion, Univ. of Delaware, Newark, DE, USA
Abstract :
Multi-step processing of Cu(In,Ga)Se2, incorporating electrodeposition (ED) of single-phase precursors coupled with physical vapor deposition (PVD) to tune film composition, is described. ED conditions for a range of precursors, including CuSe, Cu/In alloys and bi-layers, In2Se3, and Cu metal, were optimized. Precursors were processed by PVD at ~500°C for 45-60 minutes. Resultant Cu(In,Ga)Se2 devices obtained from CuSe precursors showed promising performance, ~13% efficiency, but only with KCN etching of the absorber layer following PVD. This suggests Cu2-xSe secondary phases remain in the grain boundaries. The other precursors produced poorly adhered Cu(In,Ga)Se2 films. E-beam evaporated Cu precursors gave similar results to CuSe precursors. A low toxicity electrochemical-based etch was preliminarily explored, but was less effective than KCN etching.
Keywords :
adhesion; copper compounds; electrodeposition; electrodeposits; etching; gallium compounds; grain boundaries; indium compounds; semiconductor growth; semiconductor thin films; solar cells; ternary semiconductors; vacuum deposition; CuInGaSe2; KCN etching; PVD; absorber layer; adherence; e-beam evaporation; electrochemical-based etch; electrodeposition; electron beam deposition; film composition; grain boundaries; metallic bilayers; multistep processing; physical vapor deposition; single-phase precursors; solar cell; time 45 min to 60 min; Annealing; Atherosclerosis; Chemical vapor deposition; Chemistry; Copper alloys; Costs; Etching; Grain size; Photovoltaic cells; Temperature;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE
Conference_Location :
Philadelphia, PA
Print_ISBN :
978-1-4244-2949-3
Electronic_ISBN :
0160-8371
DOI :
10.1109/PVSC.2009.5411666
