Abstract A novel MgZnO/ZnS heterojunction-based ultraviolet (UV) photodetector (PD) with high performance is fabricated by a facile sol-gel process and a successive ionic layer adsorption and reaction (SILAR) method. ZnS is coated onto the MgZnO film as an interface modification layer, which overcomes the drawbacks of the pristine MgZnO photosensitive layer, such as lower carrier mobility and more traps in the material, and greatly enhances UV-light absorption. The type-II heterostructure constructed by work function differences near the interface facilitate the separation of photogenerated carriers. Compared with the MgZnO PD, the optimized heterojunction PD (MgZnO/ZnS-10) yields a dramatically decreased dark current (≈1 nA), a remarkable responsivity (900 A/W) and an ultrahigh photo-to-dark current ratio (up to 2.3 × 105) under 325 nm light illumination at 5 V bias. These results provide a cost-efficient means for improving the properties of MgZnO PDs, and show the advantages of MgZnO/ZnS heterojunction PDs in UV detection. This study demonstrates that rational construction of novel heterojunctions holds great potential for fabricating high-performance photodetectors.

中文翻译：

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在MgZnO上采用SILAR沉积ZnS薄膜的具有超高光敏度的新型紫外光电探测器

摘要 采用简便的溶胶-凝胶工艺和连续离子层吸附反应（SILAR）方法制备了一种新型的高性能MgZnO/ZnS异质结紫外（UV）光电探测器（PD）。在MgZnO薄膜上涂覆ZnS作为界面改性层，克服了原始MgZnO光敏层载流子迁移率低、材料陷阱多等缺点，大大增强了对紫外光的吸收。通过界面附近的功函数差异构建的 II 型异质结构促进了光生载流子的分离。与 MgZnO PD 相比，优化的异质结 PD (MgZnO/ZnS-10) 产生了显着降低的暗电流 (≈1 nA)、显着的响应度 (900 A/W) 和超高的光暗电流比（高达到 2。3 × 105) 在 5 V 偏置下的 325 nm 光照下。这些结果为改善MgZnO PDs的性能提供了一种经济有效的手段，并展示了MgZnO/ZnS异质结PDs在紫外检测中的优势。这项研究表明，合理构建新型异质结对于制造高性能光电探测器具有巨大潜力。