Abstract
Post-deposition processing was conducted on ZnO thin films deposited by radio␣frequency (RF) magnetron sputtering. Rapid thermal annealing (RTA) and ion implantation followed by RTA gave increased conductivity and the latter increased Hall-effect mobility from 1.7 cm2 V−1 s−1 to 9.5 cm2 V−1 s−1 Metal–semiconductor–metal photodetectors (MSM-PDs) had a low dark current, a high ratio of photo to dark current, and a high responsivity of 2.1 A/W. Current transport mechanisms of MSM-PDs with post-annealing exhibited two primary space-charge-limited mechanisms, m > 2 and m < 1, following I ≈ V
m
. The non-annealed ZnO film gave one mechanism with m < 1 in photo I–V. Response to a femtosecond pulse gave rise and fall times in the range of 12 ns to 29 ns.
