1. UV response characteristics of mixed-phase MgZnO thin films with different structure distributions, high Iuv/Idark ratios, and fast speed MgZnO UV detectors with tunneling breakdown mechanisms
- Author
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Youming Lu, Wangying Xu, Wenjun Liu, H Xia, Deliang Zhu, Peijiang Cao, Mingzhi Fang, and Shun Han
- Subjects
Materials science ,Fast speed ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Crystal ,medicine ,General Materials Science ,Electrical and Electronic Engineering ,Thin film ,Quantum tunnelling ,business.industry ,Mechanical Engineering ,Response characteristics ,Detector ,Biasing ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Mechanics of Materials ,Optoelectronics ,0210 nano-technology ,business ,Ultraviolet - Abstract
High-performance ultraviolet (UV) detectors with both high responses and fast speeds are hard to make on homogeneous crystal semiconductor materials. Here, the UV response characteristics of mixed-phase MgZnO thin films with different internal structure distributions are studied. The mixed-phase MgZnO-based detector with the given crystal composition has a high response at both deep UV light (96 A W−1 at 240 nm) and near UV light (80 A W−1 at 335 nm). Meanwhile, because of the quasi-tunneling breakdown mechanism within the device, the high-response UV detector also shows a fast response speed (tr = 0.11 μs) and recovery speed (td1 = 26 μs) at deep UV light, which is much faster than both low-response mixed-phase MgZnO-based UV detectors with other structure constitutions and reported high-response UV devices on homogenous crystal materials. The Idark of 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 5.5 uW cm−2 235 nm UV light. The new quasi-tunneling breakdown mechanism is observed in some mixed-phase MgZnO thin films that contain both c-MgZnO and h-MgZnO parts, which introduce a high response, signal-to-noise ratio, and fast speed into mixed-phase MgZnO-based UV detectors at weak deep UV light.
- Published
- 2021