MgZnO-Based Schottky Barrier Ultraviolet-B Photodiode by Ultrasonic Spray Pyrolysis Deposition

This article demonstrates a Mg
_0.4
Zn
_0.6
O-based ultraviolet-B photodiode using ultrasonic spray pyrolysis deposition (USPD). The material characteristics of the USPD-deposited Mg
_0.4
Zn
_0.6
O thin film are investigated by the X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence,and ellipsometer. Schottky photodiode is fabricated by using Pt as the anode and Ti/Au as the cathode. Note that 0.84-eV Schottky barrier height is formed between Pt and Mg
_0.4
Zn
_0.6
O. The present Schottky barrier photodiode shows high rectification ratio of 10
⁴
and high ultraviolet-to-visible rejection ratio of 1.83 × 10
⁵
. Furthermore, the specific detectivity is over 10
¹¹
Jones at ultraviolet-B region.