Effects of Substrate Orientation on the Photovoltaic Performance of InGaAs Solar Cells

In
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Ga
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As solar cells grown on GaAs substrates with different miscut angles via metalorganic chemical vapor deposition were utilized to study the effect of substrate orientation on solar cell efficiency. A p-n In
_0.16
Ga
_0.84
As solar cell grown on a 2°-off GaAs substrate exhibited better conversion efficiency than one grown on a 15°-off GaAs substrate. The poor performance of the 15°-off In
_0.16
Ga
_0.84
As solar cell could be attributed to the formation of high-density misfit dislocations through strain relaxation, thereby reducing the minority carrier lifetime. The conversion efficiency of a 15°-off In
_0.16
Ga
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As solar cell was improved using a p-i-n structure. Using the p-i-n structure design, a 15°-off In
_0.16
Ga
_0.84
As solar cell showed conversion efficiency close to or even better than that of a 2°-off In
_0.16
Ga
_0.84
As solar cell with the same structure.