Schottky contact on ZnO nano-columnar film with H 2 O 2 treatment

The surface treatment with boiling hydrogen peroxide (H 2 O 2 ) solution on the surface of ZnO nano-columnar film was investigated. Field emission-SEM and TEM analysis revealed that amorphous ZnO 2 layer covers the ZnO nano-column surface through the H 2 O 2 treatment at 100°C for 1 min. X-ray photoemission spectroscopy (XPS) has been conducted on the H 2 O 2 treated ZnO surface. The surface exhibits high resistive conductivity after the H 2 O 2 treatment, suggesting that the treatment promotes a compensation effect. We demonstrate that dramatic improvement in the rectifying behavior on the Schottky diodes can be achieved by inserting a ZnO 2 interface layer between the Pt Schottky electrode and the ZnO nano-column film. The ZnO 2 interface layer promotes surface passivation and suppresses the surface leakage current. This is expected to increase the Schottky barrier height to 0.78 eV. The H 2 O 2 treated Schottky diode showed five orders of magnitude in current rectification between forward and reverse bias at 3 V.