Electrophotoluminescence of ZnO film

The electric-field-controlled photoluminescence (PL), i.e., electrophotoluminescence (EPL) of ZnO film has been investigated via a ZnO-based metal-insulator-semiconductor (MIS) structure on a silicon substrate applied with different biases. Compared with the PL of ZnO film in the case where there is no bias on the MIS structure, the positive bias with negative voltage applied on silicon substrate significantly enhances the near-band-edge ultraviolet emission while suppressing the deep-level-related visible emissions, whereas the negative bias hardly changes the PL of ZnO film. The mechanism for EPL of ZnO film is proposed in terms of the electric-field effect on the bending of energy bands of ZnO. (C) 2007 American Institute of Physics.