Solar Energy Conversion Properties and Defect Physics of ZnSiP2
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. ZnSiP2 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 ZnSiP2 photovoltaic device. We show that ZnSiP2 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 ZnSiP2 are shallow and the minority carrier lifetime is 7 ns. These favorable results encourage the development of ZnSiP2 and related materials as photovoltaic absorber materials.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- NREL Laboratory Directed Research and Development (LDRD)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1245125
- Report Number(s):
- NREL/JA-5J00-66212
- Journal Information:
- Energy & Environmental Science, Vol. 9, Issue 3; Related Information: Energy and Environmental Science; ISSN 1754-5692
- Publisher:
- Royal Society of Chemistry
- Country of Publication:
- United States
- Language:
- English
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