Events Calendar

Examining the Optical Properties and Polaritons of Single-Crystal Gallium Nitride

Aditya Desai; University of Iowa

Wide-bandgap semiconductors have recently come into focus as a promising area of research for many applications, including power electronics and optoelectronics, and typically involve semiconductors that have band gaps of at least 3 eV, significantly larger than the 1.12 eV band gap of silicon. Notable examples of wide-bandgap semiconductors include hexagonal boron nitride, silicon carbide, and gallium nitride. Of special interest in these materials is the study of polaritons arising when examined under incident infrared light and whether they can reveal various properties of the material in question. In this presentation, I show how to combine an experimental method based on prism coupling with a transfer-matrix-model-based optimization algorithm to characterize reflectivity data on infrared polaritons in gallium nitride. I find that this method allows for the identification of intrinsic parameters of the dielectric function for gallium nitride as well as the strength of its doping, thereby indicating that investigating the polaritons of materials can yield much information about their properties.