TY - GEN
T1 - Formation of thin-film crystalline silicon on glass observed by in-situ XRD
AU - Westra, JM
AU - Vavrunkova, V
AU - Sutta, P
AU - van Swaaij, RACMM
AU - Zeman, M
PY - 2010
Y1 - 2010
N2 - Thin-film poly-crystalline silicon (poly c-Si) on glass obtained by crystallization of an amorphous silicon (a-Si) film is a promising material for low cost, high efficiency solar cells. Our approach to obtain this material is to crystallize a-Si films on glass by solid phase crystallization (SPC). As the grain size of SPC poly c-Si films will be smaller than that of multi-crystalline wafers, lower solar cell efficiencies are expected for this technology. Despite the smaller grain size, a 2-micron-thick polycrystalline silicon solar cell with light trapping was shown to have a conversion efficiency of more than 10% [1]. Obtainable efficiencies up to 15% are expected for solar cells made using SPC of a-Si:H films. Expanding thermal plasma chemical vapor deposition (ETP-CVD) was used to prepare hydrogenated a-Si films; this technique is chosen because the deposition rates are much higher than with plasma enhanced CVD. A-Si:H films with different hydrogen contents were annealed using temperatures ranging from 500 °C to 700 °C. The evaluation of the films after annealing treatments revealed that the hydrogen content and bonding configuration did not influence the structural properties of the crystallized films significantly. The average crystallite size in the fully crystallized films was between 100 and 150 nm. Full crystallization of 1 micrometer thick films was achieved within 20 minutes for annealing at 625 °C and 650 °C. During annealing at 600 °C crystallization is much slower, and no crystallization is observed at 500 °C. The relation between the annealing temperature and the rate with which the films are fully crystallized is of great importance to develop a solar cell technology, to limit the thermal budget and processing time.
AB - Thin-film poly-crystalline silicon (poly c-Si) on glass obtained by crystallization of an amorphous silicon (a-Si) film is a promising material for low cost, high efficiency solar cells. Our approach to obtain this material is to crystallize a-Si films on glass by solid phase crystallization (SPC). As the grain size of SPC poly c-Si films will be smaller than that of multi-crystalline wafers, lower solar cell efficiencies are expected for this technology. Despite the smaller grain size, a 2-micron-thick polycrystalline silicon solar cell with light trapping was shown to have a conversion efficiency of more than 10% [1]. Obtainable efficiencies up to 15% are expected for solar cells made using SPC of a-Si:H films. Expanding thermal plasma chemical vapor deposition (ETP-CVD) was used to prepare hydrogenated a-Si films; this technique is chosen because the deposition rates are much higher than with plasma enhanced CVD. A-Si:H films with different hydrogen contents were annealed using temperatures ranging from 500 °C to 700 °C. The evaluation of the films after annealing treatments revealed that the hydrogen content and bonding configuration did not influence the structural properties of the crystallized films significantly. The average crystallite size in the fully crystallized films was between 100 and 150 nm. Full crystallization of 1 micrometer thick films was achieved within 20 minutes for annealing at 625 °C and 650 °C. During annealing at 600 °C crystallization is much slower, and no crystallization is observed at 500 °C. The relation between the annealing temperature and the rate with which the films are fully crystallized is of great importance to develop a solar cell technology, to limit the thermal budget and processing time.
KW - conference contrib. refereed
KW - Conf.proc. > 3 pag
U2 - doi:10.1016/j.egypro.2010.07.034
DO - doi:10.1016/j.egypro.2010.07.034
M3 - Conference contribution
SP - 235
EP - 241
BT - Proceedings of Inorganic and Nanostructured Photovoltaics (E-MRS 2009 Symposium B)
A2 - Beaucarne, G
A2 - Conibeer, G
A2 - Mellikov, E
A2 - Schropp, R
A2 - Topic, M
PB - Elsevier
CY - Amsterdam, The Netherlands
T2 - E-MRS 2009 Spring Meeting, Strasbourg, France
Y2 - 8 June 2009 through 12 June 2009
ER -