Photoconductive characteristics of ZnO: Al network films sputter-deposited at different deposition temperatures

50 nm-thick ZnO: Al network films were sputter-deposited on nanochannel Al2O3 substrates at 300 K, 423 K and 623 K. A photoconduction of the network films was measured by using a metal-semiconductor-metal planar configuration with Ag contact electrodes. Both the dark current and the photocurrent increase linearly with the applied voltage, meaning an ohmic contact between ZnO: Al network film and Ag electrode. The photocurrent of the network films increases with increasing deposition temperature. The network films show a slow photo-response. The rising process time constant is almost independent of deposition temperature. The photosensitivity of the network films decreases with increasing deposition temperature.