Effect of ZnTe transition layer to the performance of CdZnTe/GaN multilayer films for solar-blind photodetector applications
Effect of ZnTe transition layer to the performance of CdZnTe/GaN multilayer films for solar-blind photodetector applications
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ZnTe 过渡层对日盲光电探测器应用 CdZnTe/GaN 多层薄膜性能的影响
DOI：
10.1088/1361-6463/ab9331
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发表时间：
2020-10-07
影响因子：
3.4
通讯作者：
Min, Jiahua
中科院分区：
文献类型：
--
作者：
Sun, Jiahao;Shen, Yue;Min, Jiahua
采用近空间升华法在GaN衬底上制备了高质量的CdZnTe薄膜，并首次引入ZnTe过渡层来减小衬底与CdZnTe薄膜之间的晶格失配。用x射线衍射和扫描电子显微镜对多层膜的形貌和结构进行了表征。基于ZnTe过渡层的CdZnTe薄膜的结晶质量得到明显优化，最佳半高宽和晶粒尺寸分别为0.149 °和10.4 μ m。用X射线光电子能谱和低温光致发光对多层膜的表面缺陷进行了分析，结果表明ZnTe过渡层的引入使CdZnTe膜的Cd空位率从22.9%降低到13.3%。GaN/ZnTe/CdZnTe多层膜的电学性质也表现出类似的PN结效应，最佳的光暗电流比达到38.8。多层膜对254 nm光的响应度是对400 nm光的响应度的69.1倍，有效地提高了CdZnTe薄膜在日盲区的探测能力。
High quality CdZnTe films were prepared on GaN substrates by a close-spaced sublimation method and ZnTe transition layers were introduced to decrease the lattice mismatch between substrates and CdZnTe films for the first time. The morphology and structure of multilayer films were measured by x-ray diffraction and scanning electron microscopy. The crystalline quality of CdZnTe films based on ZnTe transition layers is obviously optimized and the best full width at half maximum and grain size of CdZnTe films are 0.149 degrees and 10.4 mu m, respectively. A surface defect analysis of multilayer films was studied by x-ray photoelectron spectroscopy and low temperature photoluminescence, which indicated that the introduction of ZnTe transition layer can reduce the Cd vacancy ratio of CdZnTe films from 22.9% to 13.3%. It is also found that the electrical properties of GaN/ZnTe/CdZnTe multilayer films show a similar PN junction effect and the best photo-dark current ratio reaches 38.8. The responsivity of multilayer films under 254 nm light is about 69.1 times more than that to 400 nm, which improves the detection of CdZnTe films in the solar-blind region effectively.