Practical Optimization of Highly Sensitive AZO Photoconductor With Circular Electrode Scheme

Highly responsive ZnO-based photoconductors with a circular electrode scheme are introduced in this paper. Some cost-effective samples were fabricated through simple chemical routes and conventional photolithography methods. Al:ZnO thin films with a high density of hole trap states were prepared after several optimizations during the synthesis process. Circular electrodes with low ohmic contact resistances were formed by optimizing the metallization process. Then, the prepared prototypes were analyzed and their specifications were measured. Performance of the devices was also investigated by using a device simulator. The experimental data showed good agreement with the simulation results. Such that the high responsivity of about 1.9 × 10
⁴
AW
^-1
and signal-to-noise ratio of 9.14 × 10
³
were recorded after optimization of annealing temperature (at 350 °C), under a weak ultraviolet illumination of 268.27 μW·cm
^-2
at 253 nm wavelength.