P-type transparent conducting CU-AL-O thin films prepared by PE-MOCVD

Abstract

P-type transparent Cu-Al-O thin films were first prepared by PE-MOCVD under different growth conditions. High conductivity was achieved after several efforts and the transparency averaged 30-50% in the visible range. The properties were systematically studied and it was found that growth temperature significantly affected the conductivity of the films and even the conduction mechanisms. Examination and comparison of both scattering mechanisms and some conduction models revealed that the films grown at different temperatures followed different conduction mechanisms. The depth distribution was observed and the uneven distribution of copper was analyzed. Peak fitting of XPS spectra showed the existence of Cu2+ which was the base of minor charge carrier. Concerning other phenomena such as Hall coefficient inversion, n-type codoping as well as the change of conductivity and bandgap with growth temperature and annealing, methodical explanations were given.