Defects in Strontium Titanate: A First Principles Study

Abstract

In recent years there has been growing interest in exploring new 2D material-based devices with improved scalability. For achieving good device performance, the need for choosing appropriate dielectrics has become evident. One promising candidate is Strontium Titanate, SrTiO3, which is a high-κ perovskite that can be transferred on 2D MoS2 and WSe2 to fabricate high-performance n- and p-type FETs. In this work we use density functional theory in conjunction with a hybrid functional to study the potential relevance of four different kinds of intrinsic defects in SrTiO3 for device performance and reliability. The defect parameters describing charge trapping are obtained using non-radiative multiphonon theory which can then be used in future TCAD and compact modeling studies. We show that based on its trap level, the titanium antisite defect is a relevant defect for MoS2/SrTiO3 based devices.