TY - GEN
T1 - Surface passivation properties of stacked doped pecvd a-Si:H layers for hetero-structure c-Si solar cells
AU - De Wolf, Stefaan
AU - Kondo, Michio
PY - 2007/12/1
Y1 - 2007/12/1
N2 - Hetero-structures, such as the crystalline silicon (c-Si) / doped plasma-enhanced chemical vapor deposited (PECVD) amorphous silicon (a-Si:H) structure, are an elegant way to avoid recombination losses at the electrical contacts of high conversion efficiency photovoltaic devices. To find a good compromise between limited charge carrier recombination at the surface and a limited resistivity of the contact, sandwich structures such as c-Si (p or n) / a-Si:H (i) / a-Si:H (p+ or n+) have been proposed in the past. In this paper we report on the surface passivation properties of such stacked doped a-Si:H layers, with a total thickness of only a few nm. Whereas subsequent deposition of a-Si:H (n+) films on thin a-Si:H (i) layers improves the surface passivation quality, a clear passivation degradation is seen when a-Si:H (i) layers are covered by a-Si:H (p+) films. The observed trends are irrespective of the wafer-type. This article discusses possible causes for these phenomena and a model for the recombination-mechanism is proposed.
AB - Hetero-structures, such as the crystalline silicon (c-Si) / doped plasma-enhanced chemical vapor deposited (PECVD) amorphous silicon (a-Si:H) structure, are an elegant way to avoid recombination losses at the electrical contacts of high conversion efficiency photovoltaic devices. To find a good compromise between limited charge carrier recombination at the surface and a limited resistivity of the contact, sandwich structures such as c-Si (p or n) / a-Si:H (i) / a-Si:H (p+ or n+) have been proposed in the past. In this paper we report on the surface passivation properties of such stacked doped a-Si:H layers, with a total thickness of only a few nm. Whereas subsequent deposition of a-Si:H (n+) films on thin a-Si:H (i) layers improves the surface passivation quality, a clear passivation degradation is seen when a-Si:H (i) layers are covered by a-Si:H (p+) films. The observed trends are irrespective of the wafer-type. This article discusses possible causes for these phenomena and a model for the recombination-mechanism is proposed.
UR - http://www.scopus.com/inward/record.url?scp=41749103091&partnerID=8YFLogxK
U2 - 10.1109/WCPEC.2006.279746
DO - 10.1109/WCPEC.2006.279746
M3 - Conference contribution
SN - 1424400163
SN - 9781424400164
T3 - Conference Record of the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion, WCPEC-4
SP - 1469
EP - 1472
BT - Conference Record of the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion, WCPEC-4
T2 - 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion, WCPEC-4
Y2 - 7 May 2006 through 12 May 2006
ER -
