Preparation and Photoelectrochemical Characterization of ZnSiAs<sub>2</sub> Crystals

Wen, Yuan-Chung; Parkinson, B. A.

doi:10.1021/jp962697+

Cited by 2 publications

(1 citation statement)

References 25 publications

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“…ZnSiP 2 ) have received less attention for optoelectronic devices. [2][3][4][5][6][7][8][9] Figure 1 shows that II-IV-V 2 chalcopyrite compounds span a broad range of band gaps, from 0.4 eV (CdSnAs 2 ) to 2.5 eV (MgSnP 2 ), and have lattice constants that are compatible with many unary and binary semiconductors. Many of the II-IV-V 2 compounds are formed from comparatively inexpensive and non-toxic elements (e.g.…”

Section: Introductionmentioning

confidence: 99%

Solar energy conversion properties and defect physics of ZnSiP₂

Martinez

Warren

Gorai

et al. 2016

Energy Environ. Sci.

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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. Broader ContextOf all the renewable energy technologies, solar photovoltaic electricity has one of the highest resource potentials; there is enough energy in the sunlight incident on the surface of the earth to meet the world's energy demands many times over (∼10,000:1). However, significant market penetration requires photovoltaics to be cost competitive with fossil fuels, even when unsubsidized. Currently, balance of system costs, rather than module costs, represent the majority of the total installed cost. Thus, increasing module efficiency is attractive as high efficiency cells can reduce installation size and therefore cost. Tandem photovoltaic architectures can provide a transformative boost in module efficiency over the single junction alternative due to reduced thermalization losses. Silicon photovoltaics is a well established (>90% market share), high efficiency, low cost technology that provides a crystalline template to grow top cells upon. However, the top cell material must satisfy strict requirements, including high efficiency and long reliability, or its presence will simply reduce the performance of the silicon bottom cell. The primary top cell materials considered to date include III-V materials, but the cost of these materials and their sensitivity to defects have proven challenging. In this work, ZnSiP 2 emerges as a wide band gap absorber that has the potential to meet the requirements needed for a top cell in tandem silicon-based photovoltaics. † Electronic Supplementary Information (ESI) available:

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