Title :
Critical issues for Cu(InAl)Se/sub 2/ thin film solar cells
Author :
Shafarman, W.N. ; Marsillac, S. ; Minemoto, T. ; Paulson, P.D. ; Birkmire, R.W.
Author_Institution :
Inst. of Energy Conversion, Delaware Univ., Newark, DE, USA
Abstract :
Cu(InAl)Se/sub 2/ thin film solar cells have been demonstrated with 16.9% efficiency using an absorber layer with Al/(In+Al)=0.13 giving a bandgap of 1.16 eV. However, the cell efficiency decreased as the Cu(InAl)Se/sub 2/ bandgap increased up to 1.7 eV. A critical development for these cells was the inclusion of a 5 nm thick Ga seed layer to improve the adhesion between the Cu(InAl)Se/sub 2/ and the Mo back contact. In this paper, critical issues for Cu(InAl)Se/sub 2/ thin film solar cells will be discussed, focusing on the film adhesion, and solar cell behavior with increasing bandgap. The effects of different flux-temperature-time profiles used for the elemental evaporation of Cu(InAl)Se/sub 2/ films, and different back contact structures will be characterized with respect to film morphology, structure, and adhesion, and to device behavior for Cu(InAl)Se/sub 2/ films with bandgaps from 1.1 to 1.5 eV. Finally, the prospects for Cu(InAl)Se/sub 2/ as the absorber layer in wide bandgap solar cells will be reviewed.
Keywords :
adhesion; aluminium compounds; copper compounds; energy gap; grain size; inclusions; indium compounds; semiconductor growth; semiconductor thin films; solar cells; surface morphology; vacuum deposition; Cu(InAl)Se/sub 2/ thin film solar cell; CuInAlSe/sub 2/; Ga seed layer; Mo; Mo back contact; absorber layer; cell efficiency; elemental evaporation; film adhesion; film morphology; film structure; flux temperature time profile; inclusion; wide bandgap solar cell;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Conference_Location :
Osaka, Japan
Print_ISBN :
4-9901816-0-3
