This study examined MgZnO thin films grown on quartz substrates using radio frequency magnetron sputtering. These films with varying Mg content were used to fabricate metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors (PDs). The best sample with optimized properties was obtained using a Mg content of 20%. The relatively high Mg content could effectively suppress the dark current to a value of the order of 10-13 A. The PD exhibited an on-off ratio of seven orders of magnitude; its photo-responsivity increased with the increasing Mg content, which caused the suppression of the dark current. The UV-to-visible rejection ratio could be up to five orders of magnitude. Furthermore, the noise equivalent power (NEP) and the normalized detectivity (D∗) of the PD fabricated with 20%Mg were determined as 6.6×10-15 Wand 6.5×10-14 cmHz0.5W-1, respectively. These results indicate that an increase in the Mg content could reduce the dark current and the noise by effectively suppressing the donor-like defects.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials