Title :
Comparison of Band Alignments at Various CdS/Cu(In,Ga)(S,Se)2 Inter-Faces in Thin Film Solar Cells
Author :
Weinhardt, L. ; Fuchs, O. ; Gross, Dominic ; Storch, G. ; Dhere, N.G. ; Kadam, A.A. ; Kulkarni, S.S. ; Visbeck, S. ; Niesen, T.P. ; Karg, F. ; Heske, C. ; Umbach, E.
Author_Institution :
Experimentelle Phys. II, Wurzburg Univ.
Abstract :
The band alignment at the CdS/Cu(In,Ga)(S,Se)2 interface, as derived in our earlier publications, are compared for different absorber compositions. The discussed band alignments were directly determined using a combination of UV- and X-ray photoemission and inverse photoemission. While a flat conduction band alignment can be found for low-gap material, the cell structure with a high-gap absorber shows a cliff-like alignment. The different alignments can be correlated with the respective cell parameters, explaining why the expected linear gain in open circuit voltage for the high-gap absorbers has not yet been achieved
Keywords :
II-VI semiconductors; X-ray photoelectron spectra; cadmium compounds; conduction bands; copper compounds; gallium compounds; indium compounds; solar absorber-convertors; solar cells; ternary semiconductors; thin film devices; CdS-Cu(InGa)(SSe)2; UV-photoemission; X-ray photoemission; absorber compositions; cell structure; cliff-like alignment; flat conduction band alignments; high-gap absorber; inverse photoemission; linear gain; low-gap material; open circuit voltage; semiconductor interface; thin film solar cells; Buffer layers; Chemical processes; Gain; Photoelectricity; Photovoltaic cells; Production; Solar energy; Transistors; Uninterruptible power systems; Voltage;
Conference_Titel :
Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
1-4244-0017-1
Electronic_ISBN :
1-4244-0017-1
DOI :
10.1109/WCPEC.2006.279477
