Characterization of AZO/p-Si heterojunction prepared by DC magnetron sputtering

Al-doped ZnO (AZO) film was deposited by direct-current (DC) magnetron sputtering on p-Si (1 0 0) wafer to fabricate Al-doped n-ZnO/p-Si heterojunctions. The microstructural, optical and electrical properties of the AZO film were characterized by XRD, SEM; UV-vis spectrophotometer; four-point probe and Hall effect measurement, respectively. Results show that the AZO film is of good quality. The electrical junction properties were investigated by I-V measurement, which reveals that the heterojunction shows rectifying behavior under a dark condition. The ideality factor and the saturation current of this diode are 20.1 and 1.19 x 10(-4) A, respectively. The value of I-F/I-R (I-F and I-R stand for forward and reverse current, respectively) at 5V is found to be as high as 19.7. It shows fairly good rectifying behavior, indicating formation of a diode between AZO and p-Si. High photocurrent is obtained under a reverse bias when the crystalline quality of AZO film is good enough to transmit light into p-Si. (C) 2010 Elsevier Ltd. All rights reserved.