Effects of grain boundaries in polycrystalline silicon thin-film solar cells based on the two-dimensional model

Citation
K. Kurobe et al., Effects of grain boundaries in polycrystalline silicon thin-film solar cells based on the two-dimensional model, SOL EN MAT, 65(1-4), 2001, pp. 201-209
Citations number
5
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
SOLAR ENERGY MATERIALS AND SOLAR CELLS
ISSN journal
0927-0248 → ACNP
Volume
65
Issue
1-4
Year of publication
2001
Pages
201 - 209
Database
ISI
SICI code
0927-0248(200101)65:1-4<201:EOGBIP>2.0.ZU;2-P
Abstract
The two-dimensional calculation for polycrystalline Si thin-film solar cell s was performed. Two models, "stripe structure" and "columnar structure", w ere applied for the solar cells composed of grains. For the stripe structur e of 20 mum active layer, to keep the efficiency distribution within 5% for individual unit cells, the stripe width requires more than 500 mum for a m inority-carrier lifetime of 1 x 10(-5) s and recombination velocity at the grain boundary of 1 x 10(4) cm/s. For the columnar structure of 10 mum acti ve layer, to keep the emciency independent of grain size, the recombination velocity should be kept less than 1 x 10(3) cm/s. If imperfect passivation of a grain boundary is given, the way of decreasing carrier concentration to 10(14) cm(-3) in an active layer may realize insusceptible output. An ap propriate device modeling is needed in the two-dimensional calculation for polycrystalline Si thin films with an electron diffusion length close to or more than grain size and with a poorly passivated grain boundary. The calc ulated efficiency using bad model will include an error of about 1% as over estimation. (C) 2001 Elsevier Science B.V. All rights reserved.