Title :
Deposition conditions, hydrogen content, and the Staebler-Wronski effect in amorphous silicon
Author :
Fortman, C.M. ; Zhou, T. ; Malone, C. ; Gunes, M. ; Wronski, C.R.
Author_Institution :
Inst. of Energy Conversion, Delaware Univ., Newark, DE, USA
Abstract :
The Staebler-Wronski effect (SWE) is examined as a function of hydrogen content (CH) and the local H bond structure. The SWE is examined through the rate of degradation of solar cells due to light exposure (at room temperature) and the steady-state defect density that can be established through high-temperature (T >150°C) degradation. Structure and CH are carefully controlled by the photo-CVD (chemical vapor deposition) reactor conditions. Growth conditions for altering CH with a minimum of other changes are identified. Films with a total CH of 7 and 11% were grown at the same substrate temperature and characterized. The initial density of defects in both materials was low (~2E15/cm2-eV) but the stability was drastically reduced in the high-CH films and devices. The change in stability due to increased CH is consistent with the SW precursor being a hydrogen-rich region
Keywords :
CVD coatings; Staebler-Wronski effect; amorphous semiconductors; elemental semiconductors; hydrogen; silicon; solar cells; Staebler-Wronski effect; amorphous Si:H solar cells; degradation; growth conditions; light exposure; local H bond structure; photo-CVD; stability; steady-state defect density; substrate temperature; Amorphous materials; Amorphous silicon; Bonding; Degradation; Energy conversion; Hydrogen; Inductors; Polymers; Predictive models; Stability;
Conference_Titel :
Photovoltaic Specialists Conference, 1990., Conference Record of the Twenty First IEEE
Conference_Location :
Kissimmee, FL
DOI :
10.1109/PVSC.1990.111888
