The study of piezotronic and piezo-phototronic features in semiconducting piezoelectrics has gained considerable attention for optimizing electronic and optoelectronic device performance. In this study, we explore the photocurrent response within a ZnO varistor-type interface device and examine its UV photosensitivity enhancement through piezo-phototronic modulation of the potential barriers at grain boundaries. Doped ZnO bicrystals were synthesized using the epitaxial solid-state transformation method with polarization vectors perpendicular to the interface. The vectors can be directed both into and out of the interfaces depending on the crystallographic orientation of the crystals designated as (0001̅)|(0001̅) and (0001)|(0001) interfaces, respectively. These varistor-type boundaries demonstrate an exceptional photoelectric response to UV photons. Furthermore, our results indicate that the photoresponsivity of bicrystals with (0001)|0001 crystallographic orientation can be further enhanced under piezo-phototronic influence. Application of compressive stress of 100 MPa not only increased photocurrent formation by 1000 % but also boosted photosensitivity by 1400 %, attributed to the elevated double Schottky barrier (DSB) height at the interface resulting from mechanical loading on the bicrystal. Our findings highlight the significant role of piezoelectrically tuned potential barriers at grain boundaries in enhancing the separation and extraction of photogenerated excitons for photocurrent formation. This study introduces the engineered varistor-type interface as a promising candidate for future optoelectronic devices and contributes to our understanding of the piezo-phototronic concept in semiconductor-semiconductor interface devices.

中文翻译：

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ZnO 压敏电阻型接口器件中的压电调谐光敏性


半导体压电器件中的压电电子学和压电光电子学特性的研究对于优化电子和光电器件的性能引起了广泛的关注。在这项研究中，我们探索了 ZnO 压敏电阻型接口器件内的光电流响应，并通过晶界势垒的压电光电子调制来检查其紫外光敏性的增强。采用偏振矢量垂直于界面的外延固态转变方法合成了掺杂ZnO双晶。矢量可以定向进入和引出界面，具体取决于分别指定为 (0001̅)|(0001̅) 和 (0001)|(0001) 界面的晶体的晶体取向。这些压敏电阻型边界表现出对紫外光子的出色光电响应。此外，我们的结果表明，在压电光电子影响下，具有（0001）|0001晶体取向的双晶的光响应性可以进一步增强。施加 100 MPa 的压应力不仅使光电流形成增加了 1000%，而且还使光敏度提高了 1400%，这归因于双晶上的机械负载导致界面处双肖特基势垒 (DSB) 高度的升高。我们的研究结果强调了晶界处压电调谐势垒在增强光生激子的分离和提取以形成光电流方面的重要作用。这项研究介绍了工程压敏电阻型接口作为未来光电器件的有希望的候选者，并有助于我们理解半导体-半导体接口器件中的压电光电子学概念。