All-inorganic perovskites have attracted increasing attention because of their strong environmental stability and excellent photoelectric properties. However, the limited spectral response range of perovskite photodetectors restricts them in practical applications. In this work, an ultraviolet–visible photodetector with a wide spectral response and a high responsivity was prepared by constructing a CsPbBr3 quantum dots (QDs)/p-GaN heterojunction. The type-II energy band alignment formed by the heterojunction is conducive to the transport of photogenerated carriers, resulting in a high responsivity. Under certain conditions, the device can obtain responsivity values of 5 A/W and 850 mA/W under 350 and 725 nm illumination, respectively, which are comparable to those of other perovskite-based photodetectors. In addition, the photoresponse mechanism of the device is revealed through first-principles calculations of the heterojunction and the device. The enhanced light absorption of the heterojunction and the special band bending under different bias voltages improve the photoelectric performance of the device. This work can provide valuable insights into high-performance photodetectors based on all-inorganic perovskite QDs heterojunctions in terms of band regulation and device performance improvement.

中文翻译：

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用于紫外-可见光谱光电探测器的 CsPbBr3 钙钛矿量子点/p-GaN 异质结


全无机钙钛矿因其强大的环境稳定性和优异的光电性能而受到越来越多的关注。然而，钙钛矿光电探测器有限的光谱响应范围限制了它们在实际应用中的表现。在这项工作中，通过构建 CsPbBr3 量子点 （QD）/p-GaN 异质结，制备了一种具有宽光谱响应和高响应度的紫外-可见光光电探测器。异质结形成的 II 型能带对准有利于光生载流子的传输，从而产生高响应度。在某些条件下，该器件在 350 nm 和 725 nm 照明下分别可以获得 5 A/W 和 850 mA/W 的响应值，与其他基于钙钛矿的光电探测器相当。此外，通过异质结和器件的第一性原理计算揭示了该器件的光响应机制。异质结增强的光吸收和在不同偏置电压下的特殊带弯曲提高了器件的光电性能。这项工作可以为基于全无机钙钛矿 QDs 异质结的高性能光电探测器在能带调节和器件性能改进方面提供有价值的见解。