Defects in Strontium Titanate: A First Principles Study

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, SrTiO
3
, which is a high-κ perovskite that can be transferred on 2D MoS
2
and WSe
2
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 SrTiO
3
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 MoS
2
/SrTiO
3
based devices.