ZnO-based resonant cavity enhanced metal–semiconductor–metal ultraviolet photodetectors

Employing the vapor cooling condensation system and the distributed Bragg reflectors (DBRs), an intrinsic zinc-oxide (i-ZnO) film and Fabry–Perot cavity were deposited and used as the structure of the ZnO-based resonant cavity enhanced metal–semiconductor-metal ultraviolet photodetectors (RCE MSM UV PDs). The reflection of the DBRs with 18.5 and 2.5 HfO2/SiO2 pairs at a wavelength of 305 nm was 98.9% and 33.7%, respectively. Owing to the RCE structure, the 50 nm-thick ZnO-based RCE MSM UV PDs exhibited a UV–visible ratio of 265, a photoresponsivity of 0.268 A/W, and a detectivity of 1.19 × 1010 cm Hz0.5 W−1 at a wavelength of 305 nm.

► The vapor cooling condensation system was used to deposit high quality i-ZnO films. ► The ZnO-based MSM UV PD was fabricated with resonant cavity enhanced (RCE) structure. ► The 50 nm-thick ZnO-based RCE MSM UV PDs had good optoelectronic performance.