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.

As accepted by EES on December 11th, 2015

References in corpus (1)

• Combinatorial Insights into Doping Control and Transport Properties of Zinc Tin Nitride

Cited by in corpus (1)

• Gallium-Boron-Phosphide (GaBP${}_2$): A New III-V Semiconductor for photovoltaics