Title :
Relationship between the photo-induced degradation characteristics and film structure of a-Si:H films prepared under various conditions
Author :
Nishimoto, Tomonori ; Takai, Madoka ; Kondo, Michio ; Matsuda, Akihisa
Author_Institution :
Thin Film Silicon Solar Cells Superlab, Electrotech. Lab., Ibaraki, Japan
Abstract :
We have investigated the photo-induced degradation characteristics of high growth-rate (~20 Å/s) a-Si:H films prepared under various conditions and find that the stability of the film is closely related to the Si-H2 bond density in the film. The results obtained by the Schottky cell measurements indicate that highly stable films with low Si-H2 bond density are obtained at moderately high temperatures of around 350°C. As our first trial, we made a small number of nip solar cells at high growth-rate (~20 A/s) and confirmed the consistency between the result of the Schottky cell behavior and the solar cell performance. The best performance cell we have obtained so far exhibits a 9.3% initial efficiency, with a stabilized efficiency of 7.4% after a 500 h, AM1.5, 100 mW/cm2 light exposure
Keywords :
Fourier transform spectroscopy; amorphous semiconductors; hydrogen; hydrogen bonds; infrared spectroscopy; plasma CVD coatings; semiconductor thin films; silicon; solar cells; 350 C; 500 h; 7.4 to 9.3 percent; FT-IR measurements; Schottky cell measurements; Si-H2; Si-H2 bond density; Si:H; VHF-PECVD; a-Si:H films; film stability; film structure; high growth-rate a-Si:H films; nip solar cells; photo-induced degradation characteristics; solar cells; Degradation; Electrodes; Hydrogen; Photovoltaic cells; Plasma measurements; Plasma temperature; Semiconductor films; Silicon; Stability; Substrates;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.916023
