Thin film growth and band lineup of In2O3 on the layered semiconductor InSe

Thin films of the transparent conducting oxide In2O3 have been prepared in ultrahigh vacuum by reactive evaporation of indium. X-ray diffraction, optical, and electrical measurements were used to characterize properties of films deposited on transparent insulating mica substrates under variation of the oxygen pressure. Photoelectron spectroscopy was used to investigate in situ the interface formation between In2O3 and the layered semiconductor InSe. For thick In2O3 films a work function of Phi=4.3 eV and a surface Fermi level position of E-F-E-V=3.0 eV is determined, giving an ionization potential I-P=7.3 eV and an electron affinity chi=3.7 eV. The interface exhibits a type I band alignment with Delta E-V=2.05 eV, Delta E-C=0.29 eV, and an interface dipole of delta=-0.55 eV. (C) 1999 American Institute of Physics. [S0021-8979(99)08322-X].