Title :
Impurity and defect passivation in poly-Si films fabricated by aluminium-induced crystallisation
Author :
Widenborg, Per I. ; Sproul, Alistair B. ; Aberle, Armin G.
Author_Institution :
Centre of Excellence for Adv. Silicon Photovoltaics & Photonics, Univ. of New South Wales, Sydney, NSW, Australia
Abstract :
Data from resistivity, optical transmission and reflectance, and open-circuit voltage (V/sub oc/) measurements show hydrogen or ammonia plasma treatment greatly reduces the effective doping concentration, the parasitic optical absorption and improves the minority carrier properties of poly-Si films fabricated by aluminium-induced crystallisation (AIC) on glass substrates. Two 450 nm thick AIC poly-Si films on glass, one hydrogenated and one non-hydrogenated, were used to fabricate poly-Si/a-Si:H heterojunctions. The non-hydrogenated sample had a 1-sun V/sub oc/ of 136 mV and the hydrogenated sample had a 1-sun V/sub oc/ of 236 mV. The poor V/sub oc/ indicates that AIC poly-Si films are more suitable as seed layers than as absorber layers. However, heterojunctions are sensitive to surface conditions and thus further V/sub oc/ improvements may be possible by surface optimization of the hydrogenated AIC poly-Si film prior to the formation of the heterojunction.
Keywords :
crystallisation; doping profiles; electrical resistivity; elemental semiconductors; focused ion beam technology; hydrogenation; impurity distribution; minority carriers; passivation; plasma CVD coatings; plasma materials processing; semiconductor heterojunctions; semiconductor thin films; silicon; sputter etching; ultraviolet spectra; 136 mV; 236 mV; 450 nm; Si; aluminium induced crystallisation; ammonia plasma treatment; defect passivation; doping concentration; heterojunctions; hydrogen treatment; hydrogenated poly silicon films; hydrogenation; impurity passivation; minority carrier property; open circuit voltage; optical transmission; parasitic optical absorption; poly Si film; reflectance; resistivity; sputter etching; surface optimization;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Conference_Location :
Osaka, Japan
Print_ISBN :
4-9901816-0-3