Translating XPS Measurement Procedure for Band Alignment into Reliable Ab-initio Calculation Method

摘要

Band alignment between solids is a crucial issue in condensed matter physicsand electronic devices. Although the XPS method has been used as a routinemethod for determination of the band alignment, the theoretical calculations bycopying the XPS band alignment procedure usually fail to match the measuredresults. In this work, a reliable ab-initio calculation method for bandalignment is proposed on the basis of the XPS procedure and in consideration ofsurface polarity and lattice deformation. Application of our method to anataseand rutile TiO2 shows well agreement between calculation and experiment.Furthermore, our method can produce two types of band alignment: the coupledand the intrinsic, depending on whether the solid/solid interface effect isinvolved or not. The coupled and intrinsic band alignments correspond toalignments measured by XPS and electrochemical impedance analysis,respectively, explaining why band alignments reported by these two experimentsare rather inconsistent.