Silicon-based photodetectors in photoelectric sensing applications are crucial. In the previous studies of the piezo-phototronic effect on performance modulation of Si/ZnO heterojunctions, the majority is based on a rigid silicon substrate and a ZnO one-dimensional nanostructure, causing incompatibility with advanced semiconductor processing technology as well as the limitation in the field of wearable application. Here, flexible p-Si/n-ZnO film heterojunction photodetectors have been constructed by sputtering ZnO films on chemically thinned Si substrates. Under 405 nm light illumination and at −0.5 V bias, the reverse photocurrent of the heterojunction under the −0.73‰ compression strain increased by 50.36% compared to that under a strain-free state, while the reverse photocurrent for the same device under 0.73‰ tensile strain decreased by 29.2% compared to that under the strain-free state. The introduction of a flexible silicon wafer realizes a bidirectional photocurrent response regulation, which lies in the fact that the strain-induced piezo-potential governs the local energy band structure at the heterojunction interface and, thus, influences the carrier transport in the heterojunction region. The COMSOL simulation results further verify the evolution of the energy band structure at the heterojunction interface at different strain states. This work provides a strategy to design silicon-based optoelectronic devices via the piezo-phototronic effect of a ZnO film.

中文翻译：

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通过压电光电效应调节柔性 Si/ZnO 薄膜异质结光电探测器的光响应性能

光电传感应用中的硅基光电探测器至关重要。在先前关于压电光电子效应对 Si/ZnO 异质结性能调制的研究中，大多数是基于刚性硅衬底和 ZnO 一维纳米结构，导致与先进的半导体加工技术不兼容以及在可穿戴应用领域。在这里，柔性 p-Si/n-ZnO 膜异质结光电探测器已经通过在化学减薄的 Si 衬底上溅射 ZnO 膜来构建。在405 nm光照和-0.5 V偏压下，-0.73‰压缩应变下异质结的反向光电流比无应变状态下增加了50.36%，而同一器件在0.73‰压缩应变下的反向光电流增加了50.36%拉伸应变降低了 29。2% 与无应变状态下的相比。柔性硅片的引入实现了双向光电流响应调节，这在于应变诱导的压电电位控制异质结界面处的局部能带结构，从而影响异质结区域的载流子传输。COMSOL 仿真结果进一步验证了异质结界面在不同应变状态下能带结构的演变。这项工作提供了一种通过 ZnO 薄膜的压电光电效应设计硅基光电器件的策略。这在于应变诱导的压电势控制异质结界面处的局部能带结构，从而影响异质结区域的载流子传输。COMSOL 仿真结果进一步验证了异质结界面在不同应变状态下能带结构的演变。这项工作提供了一种通过 ZnO 薄膜的压电光电效应设计硅基光电器件的策略。这在于应变诱导的压电势控制异质结界面处的局部能带结构，从而影响异质结区域的载流子传输。COMSOL 仿真结果进一步验证了异质结界面在不同应变状态下能带结构的演变。这项工作提供了一种通过 ZnO 薄膜的压电光电效应设计硅基光电器件的策略。