Raman tensor of zinc-phosphide (ZnP): from polarization measurements to simulation of Raman spectra.

Zinc phosphide (ZnP) is a II-V compound semiconductor with promising photovoltaic and thermoelectric applications. Its complex structure is susceptible to facile defect formation, which plays a key role in further optimization of the material. Raman spectroscopy can be effectively used for defect characterization. However, the Raman tensor of ZnP, which determines the intensity of Raman peaks and anisotropy of inelastic light scattering, is still unknown. In this paper, we use angle-resolved polarization Raman measurements on stoichiometric monocrystalline ZnP thin films to obtain the Raman tensor of ZnP. This has allowed determination of the Raman tensor elements characteristic for the A, B and B vibrational modes. These results have been compared with the theoretically obtained Raman tensor elements and simulated Raman spectra from the lattice-dynamics calculations using first-principles force constants. Excellent agreement is found between the experimental and simulated Raman spectra of ZnP for various polarization configurations, providing a platform for future characterization of the defects in this material.