Size-selected CZTS NCs reveal phonon confinement that manifests itself in an upward shift of the main phonon peak by about 3–4 cm⁻¹ by varying the NC diameter from 3 to 2 nm. © 2016 IOP Publishing Ltd (not subject to copyright in the USA)/Contribution of the National Renewable Energy Laboratory.Ī Raman spectroscopic study of Cu2ZnSnS4 (CZTS) nanocrystals (NCs) produced by a “green” synthesis in aqueous solutions is reported. Overall, this review provides a framework for evaluating tetrahedrally bonded semiconducting compounds with respect to their defect behavior for photovoltaic and other applications, and suggests new materials that may not be as prone to such imperfections. Therefore, it is not sufficient to assess only the point defect behavior of new multinary tetrahedrally bonded compounds effects such as structural disorder and extended antisite defects must also be considered. In the case of Cu2SnS3 and Cu2ZnSnS4, structural disorder and entropy-driven cation clustering can result in nanoscale compositional inhomogeneities which detrimentally impact the electronic transport. We find that evaluation of point defects alone is not sufficient to understand defect behavior in multinary tetrahedrally bonded semiconductors. We contrast our findings on Cu2SnS3 with other chemically related Cu-Sn-S compounds, as well as structurally related compounds such as Cu2ZnSnS4 and Cu(In,Ga)Se2.
We applied experimental and theory techniques to understand point defects, structural disorder, and extended antisite defects in one semiconductor of interest for photovoltaic applications, Cu2SnS3. In this review, we describe our work investigating defects in tetrahedrally bonded, multinary semiconductors, and discuss the place of our research within the context of publications by other groups. Defects are critical to understanding the electronic properties of semiconducting compounds, for applications such as light-emitting diodes, transistors, photovoltaics, and thermoelectrics.
0 kommentar(er)
