Universal scaling of the electronic and the elastic energies of small polarons revealed by high-throughput first-principles calculations

Formation of self-trapped holes (STH) in a comprehensive list of scintillator materials, including halides and chalcogenides, are studied using an accurate and computationally efficient first-principles method, the polaron self-interaction correction (pSIC). The key characteristics of small hole polarons, including their geometries, energies and degree of localization, are found vastly different from halides to oxides to systems with open-shell cations. Nevertheless, we find a universal linear relation between the energy gap separating the bound hole level from the valence band maximum and the elastic energy associated with the lattice displacement field that accompanies the polaron.