Mg0.35Zn0.65O/Al/ZnO Photodetectors With Capability of Identifying Ultraviolet-A/Ultraviolet-B

This article proposes an Mg
_0.35
Zn
_0.65
O/Al/ZnO structure, with which photodetectors (PDs) are able to identify ultraviolet (UV)-A (400-320 nm) and UV-B (320-280 nm). Both Mg
_0.35
Zn
_0.65
O and ZnO thin films are deposited using mist atmospheric pressure chemical vapor deposition (MAPCVD) method. At first, the material characteristics such as crystal structure, oxygen deficiency, energy bandgap, and photoluminescence (PL) of Mg
_0.35
Zn
_0.65
O and ZnO thin films are analyzed. The present Mg
_0.35
Zn
_0.65
O/Al/ZnO PD shows UV-B to UV-A rejection ratio of 15 in the spectral responsivity characteristics. Additionally, the detectivity characteristics suggest that the present Mg
_0.35
Zn
_0.65
O/Al/ZnO PD is able to identify UV-A and UV-B. Furthermore, the Mg
_0.35
Zn
_0.65
O/ZnO hetero-interface enhances the carrier mobility which further improves the response time.