Fig. 1.
(Color online) Micrographs from two samples and reference wafer after preferential etching, (a)-(c) are belong to sample A, (d)-(f) for reference wafer, (g)-(I) for sample B.
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| Citation: |
Kewei Cao, Tong Liu, Jingming Liu, Hui Xie, Dongyan Tao, Youwen Zhao, Zhiyuan Dong, Feng Hui. Evaluation of four inch diameter VGF-Ge substrates used for manufacturing multi-junction solar cell[J]. Journal of Semiconductors, 2016, 37(6): 063002. doi: 10.1088/1674-4926/37/6/063002
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K W Cao, T Liu, J M Liu, H Xie, D Y Tao, Y W Zhao, Z Y Dong, F Hui. Evaluation of four inch diameter VGF-Ge substrates used for manufacturing multi-junction solar cell[J]. J. Semicond., 2016, 37(6): 063002. doi: 10.1088/1674-4926/37/6/063002.
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Evaluation of four inch diameter VGF-Ge substrates used for manufacturing multi-junction solar cell
DOI: 10.1088/1674-4926/37/6/063002
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Abstract
Low dislocation density Ge wafers grown by a vertical gradient freeze (VGF) method used for the fabrication of multi-junction photovoltaic cells (MJC) have been studied by a whole wafer scale measurement of the lattice parameter, X-ray rocking curves, etch pit density (EPD), impurities concentration, minority carrier lifetime and residual stress. Impurity content in the VGF-Ge wafers, including that of B, is quite low although B2O3 encapsulation is used in the growth process. An obvious difference exists across the whole wafer regarding the distribution of etch pit density, lattice parameter, full width at half maximum (FWHM) of the X-ray rocking curve and residual stress measured by Raman spectra. These are in contrast to a reference Ge substrate wafer grown by the Cz method. The influence of the VGF-Ge substrate on the performance of the MJC is analyzed and evaluated by a comparison of the statistical results of cell parameters. -
References
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