We present a mechano-chemical technique to obtain highly transparent and conducting Al doped ZnO (AZO) film by annealing two Zn coated AZO films in a face-to-face condition in Ar. This transparent conducting oxide (TCO) layer shows a carrier concentration of 2.29 x 10(21) cm (3), mobility of 24.11 cm(2)/Vs and resistivity of similar to 10 (4) Omega cm for 15 nm Zn coated film. The p-Si/AZO heterojunction shows a high rectification ratio of 1.1 x 10(3). Under white light illumination, the forward current of the junction is enhanced by similar to 1 order of magnitude compared to that under dark condition implying its promising photodiode applications. (C) 2012 Elsevier B.V. All rights reserved.