In situ preparation and interface characterization of TiO2/Cu2S heterointerface

The electronic structures and interface properties of the TiO2/Cu2S interface have been in situ studied after each growth step by x-ray and ultraviolet photoelectron spectroscopy. The p-doped Cu2S films (BEVBM=0.1 eV) were grown on the highly n-doped chemical vapor deposition prepared TiO2 (BEVBM=3.4 eV) films by thermal evaporation in a multistep growth procedure. The conduction band offset (0.7 eV), valence band offset (2.9 eV) and interface dipole (0.5 eV) were determined based on the quantitative examination of band bending occurring in the Cu2S films at higher coverage, leading to a staggered energy level configuration. (C) 2003 American Institute of Physics.