High-performance solar-blind ultraviolet photodetector based on mixed-phase ZnMgO thin film
High-performance solar-blind ultraviolet photodetector based on mixed-phase ZnMgO thin film
复制标题
基于混相ZnMgO薄膜的高性能日盲紫外光电探测器
DOI：
10.1063/1.4889914
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发表时间：
2014-07-07
影响因子：
4
通讯作者：
Shen, D. Z.
中科院分区：
文献类型：
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作者：
Fan, M. M.;Liu, K. W.;Shen, D. Z.
采用等离子体辅助分子束外延技术在a面蓝宝石表面沉积了高Mg含量的混合相zn0.38 mg0.62，并在此基础上制备了金属-半导体-金属日盲紫外（UV）光电探测器。在5v时，暗电流仅为0.25 pA，远低于已有报道的混合相ZnMgO光电探测器。更有趣的是，与其他包含两个光响应带的混合相ZnMgO光电探测器不同，该器件只有一个响应峰，其- 3db截止波长约为275 nm。在10v时，260 nm处的峰值响应度高达1.664 A/W，对应于内部增益为~ 8。内部增益主要归因于晶界处的界面态作为光生空穴的捕获中心。鉴于混合相ZnMgO光电探测器相对于单相ZnMgO光电探测器具有制作简单、响应率高、暗电流小等优点，我们的研究结果有望为ZnMgO日盲紫外光电探测器的开发开辟新的道路。
High Mg content mixed-phase Zn0.38Mg0.62O was deposited on a-face sapphire by plasma-assisted molecular beam epitaxy, based on which a metal-semiconductor-metal solar-blind ultraviolet (UV) photodetector was fabricated. The dark current is only 0.25 pA at 5 V, which is much lower than that of the reported mixed-phase ZnMgO photodetectors. More interestingly, different from the other mixed-phase ZnMgO photodetectors containing two photoresponse bands, this device shows only one response peak and its −3 dB cut-off wavelength is around 275 nm. At 10 V, the peak responsivity is as high as 1.664 A/W at 260 nm, corresponding to an internal gain of ∼8. The internal gain is mainly ascribed to the interface states at the grain boundaries acting as trapping centers of photogenerated holes. In view of the advantages of mixed-phase ZnMgO photodetectors over single-phase ZnMgO photodetectors, including easy fabrication, high responsivity, and low dark current, our findings are anticipated to pave a new way for the development of ZnMgO solar-blind UV photodetectors.