Abstract
This study demonstrates an improvement in the photodetection response of a Cupric Oxide (CuO) thin film through the annealing process. The CuO thin film (400 nm thickness) was deposited on a silicon substrate using DC magnetron sputtering system. Annealing of the as-deposited film was carried out in a muffle furnace at 400 and 500 oC for two hours. X-ray diffraction pattern revealed the formation of a single phase CuO film whose crystallinity improved with increase of the annealing temperature. The field emission scanning electron microscopy indicated a compact and fine granular strcutre of the as-seposited film whereas the segregation and agglomeration of grains was observed after the film’s annealing. The photodetection performance of CuO film with Al contacts was investigated under the exposure of visible light (λ = 460 nm). The current-voltage graphs of as-deposited and annealed films displayed Schottky contact formation between the metal and semiconductor, owing to a lower work function of Al than that of the CuO. The photo-to-dark current ratio of the device was significantly enhanced after the film’s annealing. The increase in photocurrent became more pronounced upon increasing the light intensity from 58.4 to 511 µW/cm2. The maximum current gain and sensitivity values were found to be 66 and 7086.8 % respectively at 10V bias for the film annealed at 500 oC. The rise and fall time of the Al/CuO/Al photodetector was decreased after the film’s annealing.
Enhanced photodetection performance of sputtered cupric oxide thin film through annealing process
