GaTlP – a Novel Semiconductor for Thermophotovoltaic Applications

29th European Photovoltaic Solar Energy Conference and Exhibition; 280-283
Thermophotovoltaics has recently garnered significant interest in the field of renewable energy. This is due to their versatility and promise to achieve efficiencies well beyond the Shockeley-Queisser Limit that dictates the performance of photovoltaics [1,2]. Thermophotovoltaics generate electricity from heat converted into infrared photons. In this study, we focus our attention to Ga1-xTlxP, a tertiary compound with the potential of having a lower bandgap with increasing Thallium (Tl) content. TlP belongs to a group of materials known as semi-metals and possesses an optical bandgap below zero [3]: This implies that the material bandgap can theoretically change from 2.26 eV (x=0) to -0.27 eV (x=1). Presented in this study are the implications such a band structure change could have on the associated properties such as the optical bandgap and lattice constant of GaTlP with varying Tl content. The versatility in Tl content allows for a number of candidate substrates including GaAs, Ge, and InP.