Loading...
Development of thin film a-SiO:H/a-Si:H double-junction solar cells and their temperature dependence
Author(s)
Sriprapha, Kobsak
Hongsingthong, Aswin
Krajangsang, Taweewat
Inthisang, Sorapong
Jaroensathainchok, Suttinan
Limmanee, Amornrat
Titiroongruang, Wisut
Sritharathikhun, Jaran
Date Issued
November 1, 2013
Type
Conference Paper
Abstract
Hydrogenated amorphous silicon oxide (a-SiO:H)/hydrogenated amorphous silicon (a-Si:H) double-junction solar cells with a high open-circuit voltage (Voc) and a low temperature coefficient (TC) were developed using a wide bandgap a-SiO:H film as the intrinsic (i) layer of the top cell. It was found that with an increasing carbon dioxide (CO2)/silane (SiH 4) ratio, the optical bandgap (Eopt) of the a-SiO:H films increased remarkably while the photogain tended to decrease. By employing an optimized a-SiO:H film as the i top layer of the a-SiO:H/a-Si:H solar cell, an initial conversion efficiency (η) of 10.2% was obtained. This solar cell showed a higher η than the conventional a-Si:H/a-Si:H structure, a result of incremental improvements in the Voc and short-circuit current density (Jsc), which were attributed to the wider bandgap of the intrinsic top layer. It was found that the TC for η of the a-SiO:H/a-Si:H solar cell was -0.10%/°C, slightly lower than that of the a-Si:H/a-Si:H solar cell, whose TC value is about -0.15%/°C. The light-induced degradation (LID) ratio for η of the a-SiO:H/a-Si:H solar cell was approximately 19%, which was 2% lower than that of the a-Si:H/a-Si:H solar cell. These results have demonstrated the great potential of the i-a-SiO:H films as absorber layers of top cells in multi-junction silicon-based thin-film solar cells. The a-SiO:H/a-Si:H solar cells with low TCs and low LID ratios are attractive for their potential use in high-temperature environments or tropical regions. © 2013 Elsevier B.V.
Citation
Thin Solid Films, 546, 398-403, 2013