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arXiv · 1506.05371

Solar energy conversion properties and defect physics of ZnSiP$_2$

Abstract

Implementation of an optically active material on silicon has been a persistent technological challenge. For tandem photovoltaics using a Si bottom cell, as well as for other optoelectronic applications, there has been a longstanding need for optically active, wide band gap materials that can be integrated with Si. ZnSiP$_2$ is a stable, wide band gap (2.1 eV) material that is lattice matched with silicon and comprised of inexpensive elements. As we show in this paper, it is also a defect-tolerant material. Here, we report the first ZnSiP$_2$ photovoltaic device. We show that ZnSiP$_2$ has excellent photoresponse and high open circuit voltage of 1.3 V, as measured in a photoelectrochemical configuration. The high voltage and low band gap-voltage offset are on par with much more mature wide band gap III-V materials. Photoluminescence data combined with theoretical defect calculations illuminate the defect physics underlying this high voltage, showing that the intrinsic defects in ZnSiP$_2$ are shallow and the minority carrier lifetime is 7 ns. These favorable results encourage the development of ZnSiP$_2$ and related materials as photovoltaic absorber materials.

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BibTeXRIS

Aaron D. Martinez, Emily L. Warren, Prashun Gorai, Kasper A. Borup, Darius Kuciauskas, Patricia C. Dippo, Brenden R. Ortiz, Robin T. Macaluso, Sau D. Nguyen, Ann L. Greenaway, Shannon W. Boettcher, Andrew G. Norman, Vladan Stevanović, Eric S. Toberer, Adele C. Tamboli. 2015-06-17. Solar energy conversion properties and defect physics of ZnSiP$_2$. https://doi.org/10.1039/c5ee02884a

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