Abstract
Low-temperature thermoelectric materials are attracting increased attention for their use in cold power generators and as power supplies for self-powered wireless sensors. To improve their thermoelectric performance, it is necessary to investigate the effects of impurity dopants and crystal defects on their transport properties using experimental and theoretical approaches. However, for narrow-gap semiconducting materials, the bandgap is underestimated by conventional density functional theory calculations, which often results in incorrect predictions of carrier transport properties. The present study investigates the effects of native crystal defects in low-temperature thermoelectric semiconducting α-SrSi 2 , which has an extremely small bandgap of 13–35 meV, using first-principles calculations and adopting the Gaussian–Perdew–Burke–Ernzerhof hybrid functional. Consequently, we are able to clarify the effects of two types of point defects (i.e., vacancies and antisite defects) on the energetic stability, electronic structure, and thermoelectric performance of α-SrSi 2 and to discuss the origins of the experimental p -type conduction in pure α-SrSi 2 . • Investigation of the effect of point defects on the thermoelectric (TE) properties of α-SrSi 2 . • Clarification of the effects of point defects on α-SrSi 2 's energetic stability and structure. • Calculation of each defect's effect on α-SrSi 2 's TE transport properties. • Discussion of the origin of the experimental p-type conduction in α-SrSi 2 .
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call