A Schottky contact to p-type CuGaS2 that showed the highest rectification ratio of approximately 500 ever reported was realized using a Cu electrode on a HF/HNO3-treated surface, as well as an excellent Au ohmic contact on a HF-etched surface. The effective Schottky barrier height of 0.9 eV was obtained from the current-voltage and capacitance-voltage characteristics. The value was smaller by 1.1 eV than that calculated from the values of the work function of Cu and electron affinity of CuGaS2. The results indicated a surface pinning of the Fermi level to certain acceptor-type gap states below the midgap.
ASJC Scopus subject areas
- 化学 (全般)