Development of thin-film polycrystalline silicon solar cells by a solid phase crystallization (SPC) method
- Sanyo Electric Co., Ltd., Hirakata, Osaka (Japan). Functional Materials Research Center
Polycrystalline silicon (poly-Si) thin films prepared by the solid phase crystallization (SPC) method were studied for photovoltaic materials. To improve the properties of the poly-Si thin film, a-Si films suited to the solid phase crystallization were investigated. It was found that TA/TO (peak height ratio of TA peak and TO peak) in Raman spectra of a-Si films had the good correlation with the average grain size, and a factor for the enlargement of grain size was an increase of distortion energy stored in a-Si films. The first adoption of a textured substrate was also performed, which had effects on the enlargement of grain size in poly-Si thin films by the SPC method. By applying the a-Si films with large TA/TO value on textured substrate, the n-type poly-Si thin-film with the grain size of 6 {micro}m was fabricated and this film showed the Hall mobility of 623 cm{sup 2}/Vs (electron density: 3.0 {times} 10{sup 15} cm{sup {minus}3}). A new heterojunction technology, which was called Artificially Constructed Junction (ACJ), was developed by depositions of thin a-Si films on single-crystalline silicon (c-Si). In a solar cell using this technology, a high conversion efficiency of 18.7% was achieved. This is the highest value ever reported for solar cells in which the junctions were fabricated at a low temperature of less than 200 C. In a thin-film poly-Si solar cell (thickness: 10 {micro}m) applying this technology, a conversion efficiency of 6.3% was also obtained and a collection efficiency of 51% was achieved at a wavelength of 900 nm. This high value attributes to the hole diffusion length of 11 {micro}m, which is longer than the poly-Si thickness.
- OSTI ID:
- 201313
- Report Number(s):
- CONF-930722-; ISBN 0-8194-1266-X; TRN: IM9613%%290
- Resource Relation:
- Conference: Annual meeting of the Society of Photo-Optical Instrumentation Engineers (SPIE), San Diego, CA (United States), 11-16 Jul 1993; Other Information: PBD: 1993; Related Information: Is Part Of Optical materials technology for energy efficiency and solar energy conversion XII; Lampert, C.M. [ed.] [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.]; PB: 401 p.; Proceedings/SPIE, Volume 2017
- Country of Publication:
- United States
- Language:
- English
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