In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 1324 ( 2011)
Kurzfassung:
A CdS x Te 1-x layer forms by interdiffusion of CdS and CdTe during the fabrication of thinfilm CdTe photovoltaic (PV) devices. The CdS x Te 1-x layer is thought to be important because it relieves strain at the CdS/CdTe interface that would otherwise exist due to the 10% lattice mismatch between these two materials. Our previous work [1] has indicated that the electrical junction is located in this interdiffused CdS x Te 1-x region. Further understanding, however, is essential to predict the role of this CdS x Te 1-x layer in the operation of CdS/CdTe devices. In this study, CdS x Te 1-x alloy films were deposited by radio-frequency magnetron sputtering and coevaporation from CdTe and CdS sources. Both radio-frequency-magnetron-sputtered and coevaporated CdS x Te 1-x films of lower S content (x 〈 0.3) have a cubic zincblende (ZB) structure akin to CdTe, whereas those of higher S content have a hexagonal wurtzite (WZ) structure like that of CdS. Films become less preferentially oriented as a result of a CdCl 2 heat treatment at ∼400 ° C for 5 min. Films sputtered in a 1% O 2 /Ar ambient are amorphous as deposited, but show CdTe ZB, CdS WZ, and CdTe oxide phases after a CdCl 2 heat treatment. Films sputtered in O 2 partial pressure have a much wider bandgap than expected. This may be explained by nanocrystalline size effects seen previously [2] for sputtered oxygenated CdS (CdS:O) films.
Materialart:
Online-Ressource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/opl.2011.1151
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2011
