Effective masses of the tin sulfide influenced by intrinsic defects: A theoretical prediction

Abstract

We performed a theoretical study within the Density Functional Perturbation Theory framework to analyze the influence of intrinsic defects in the effective mass of the charge carriers of tin sulfide. We modeled the orthorhombic phase Aem2(39) space-group symmetry and evaluated defects such as residual stress and 1.6%,3.1%, and 4.7% tin vacancy concentration. Our results show that the effective masses exhibit remarkable anisotropy for both holes and electrons; they are larger parallel to the longest axis of the unit cell; besides, the effective masses of the holes present a slight increase when the concentration defect is higher. These results demonstrate that the vacancy defect modifies the effective masses and allow us to infer that large values of effective mass contribute to low mobility between parallel planes with Van der Waals forces. Consequently, it would be reasonable to propose this material like a prominent rectifier diode.