Realization of p-Type Conductivity in ZnO via Potassium Doping

Abstract

Our work focuses on the study of the electronic structure of undoped and K-doped ZnO using density functional theory as implemented in the Wien2k package. Generalized gradient approximation and GGA plus Tran-Blahamodified Becke-Johnson (TB-mBJ) were used to calculate the exchange-correlation energy. From the electronic properties, ZnO has a direct band gap in ( - ) direction with a value of 0.76 eV within GGA and 2.63 eV within GGA + TB-mBJ. For the K-doped ZnO (12.5%) the gap was found to be 1.15 eV within GGA and 3.28 eV within GGA + TB-mBJ, we have observed that an emersion of a new narrow band exists in the valence band which is mainly caused by K 3p states with a little Zn 4s and Zn 3d effect.