UV response characteristics of mixed-phase MgZnO thin films with different structure distribution and high Iuv/Idarkratio and fast speed MgZnO UV detector with tunneling breakdown mechanism

Shun Han; H Xia; Y M Lu; Wenjun Liu; Wangying Xu; M Fang; Peijiang Cao; Deliang Zhu

doi:10.1088/1361-6528/abe824

UV response characteristics of mixed-phase MgZnO thin films with different structure distribution and high I_uv/I_darkratio and fast speed MgZnO UV detector with tunneling breakdown mechanism

Nanotechnology. 2021 Feb 19. doi: 10.1088/1361-6528/abe824. Online ahead of print.

Authors

Shun Han¹, H Xia², Y M Lu³, Wenjun Liu⁴, Wangying Xu⁵, M Fang², Peijiang Cao⁴, Deliang Zhu⁴

Affiliations

¹ College of Materials Science and Engineering, Shenzhen University, Nanhai Ave 3688,Shenzhen,Guangdong,P.R.China,518060, ShenZhen, GuangDong, 518060, CHINA.
² College of Materials Science and Engineering, Shenzhen University, ShenZhen, GuangDong, CHINA.
³ ShenZhen University, ShenZhen, CHINA.
⁴ Shenzhen University, Shenzhen, Guangdong, CHINA.
⁵ Shenzhen University, Shenzhen, 518060, CHINA.

PMID: 33607629
DOI: 10.1088/1361-6528/abe824

Abstract

High performance UV detector with both high response and fast speed is hard to made on homogeneous crystal semiconductor materials. Here, the UV response characteristics of mix-phase MgZnO thin films with different internal structure distribution are studied, the mix-phase MgZnO based detector with given crystal composition own high response at both deep UV light (96 A/W at 240nm) and near UV light (80 A/W at 335nm). Meanwhile, because of quasi-tunneling breakdown mechanism within the device, the high response UV detector also show fast response speed (t_r= 0.11 µs) and recovery speed (t_d1=26 µs) at deep UV light, which are much faster than the both low response mix-phase MgZnO based UV detectors with other structure constitution and reported high response UV devices on homogenous crystal materials. The I_darkof the device is just 4.27 pA under a 5 V bias voltage, so the signal to noise ratio of the device reached 23852 at 5.5uW/cm2 235nm UV light. Therefore, new quasi-tunneling breakdown mechanism is observed in some mix-phase MgZnO thin film that contains both c-MgZnO and h-MgZnO parts, which introduced high response, signal to noise ratio and fast speed into mix-phase MgZnO based UV detector at weak deep UV light.

Keywords: PLD; UV detector; mix-phase MgZnO; tunneling breakdown.