Quantum efficiencies exceeding unity in amorphous silicon solar cells
- Utrecht Univ. (Netherlands)
The experimental observation of internal quantum efficiencies above unity in crystalline silicon solar cells has brought up the question whether the generation of multiple electron/hole pairs has to be taken into consideration also in solar cells based on direct gap amorphous semiconductors. To study photogenerated carrier dynamics, the authors have applied Intensity Modulated Photocurrent Spectroscopy (IMPS) to hydrogenated amorphous silicon p-i-n solar cells. In the reverse voltage bias region at low illumination intensities it has been observed that the low frequency limit of the AC quantum yield Y increases significantly above unit with decreasing light intensity, indicating that more than one electron per photon is detected in the external circuit. This phenomenon can be explained by considering trapping and thermal emission of photogenerated carriers at intragap atmospheric dangling bond defect centers.
- OSTI ID:
- 208138
- Report Number(s):
- CONF-941203-; ISBN 0-7803-1459-X; TRN: IM9616%%466
- Resource Relation:
- Conference: 1. world conference on photovoltaic energy conversion, Waikoloa, HI (United States), 5-9 Dec 1994; Other Information: PBD: 1994; Related Information: Is Part Of 1994 IEEE first world conference on photovoltaic energy conversion: Conference record of the twenty fourth IEEE photovoltaic specialists conference -- 1994. Volume 1; PB: 1303 p.
- Country of Publication:
- United States
- Language:
- English
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