Deep-ultraviolet (DUV) photodetectors based on wide-band-gap semiconductors have attracted significant interest across a wide range of applications in the industrial, biological, environmental, and military fields due to their solar-blind nature. As one of the most promising wide-band-gap materials, β-Ga₂O₃ provides great application potential over detection wavelengths ranging from 230 to 280 nm owing to its superior optoelectronic performance, stability, and compatibility with conventional fabrication techniques. Although various innovative approaches and device configurations have been applied to achieve highly performing β-Ga₂O₃ DUV photodetectors, the highest demonstrated responsivity of the β-Ga₂O₃ photodetectors has only been around 10⁵ A/W. Here, we demonstrate a β-Ga₂O₃ phototransistor with an ultrahigh responsivity of 2.4 × 10⁷ A/W and a specific detectivity of 1.7 × 10¹⁵ Jones, achieved by engineering a photogating effect. A β-Ga₂O₃/MgO heterostructure with an Al₂O₃ encapsulation layer is employed not only to reduce photogenerated electron/hole recombination but also to suppress the photoconducting effects at the back-channel surface of the β-Ga₂O₃ phototransistor via a defect-assisted charge transfer mechanism. The measured photoresponsivity is almost 2 orders of magnitude higher than the highest previously reported value in a β-Ga₂O₃-based photodetector, to the best of our knowledge. We believe that the demonstrated β-Ga₂O₃/MgO heterostructure configuration, combined with its facile fabrication method, will pave the way for the development of ultrasensitive DUV photodetectors utilizing oxide-based wide-band-gap materials.

中文翻译：

---

一的超高深紫外响应的β-Ga ₂ ö ₃ / MgO比异质结构为基础的光电晶体管

基于宽带隙半导体的深紫外（DUV）光电探测器由于其日盲特性，在工业，生物，环境和军事领域的广泛应用中引起了广泛的关注。作为最有前途的宽带隙材料中的一种，的β-Ga ₂ ö ₃溢检测波长范围从230到由于其优越的光电性能，稳定性，并用常规制造技术的兼容性280nm处提供了极大的应用潜力。尽管各种创新的方法和设备配置已经被应用到实现高度执行的β-Ga ₂ ö ₃ DUV光检测器，所述的最高证明响应的β-Ga ₂ ö_3个光电探测器的电流约为10 ⁵ A / W。在这里，我们证明一个的β-Ga ₂ ö ₃光电晶体管与2.4×10的超高响应⁷ A / W和1.7×10的特定探测¹⁵琼斯，通过工程改造photogating效应来实现的。甲的β-Ga ₂ ö ₃ / MgO比异质结构的Al ₂ ö ₃封装层采用不仅减少光生电子/空穴复合，而且抑制在的反向信道表面上的光导效应的β-Ga ₂ ö ₃光电二极管通过缺陷辅助电荷转移机制。所测得的光响应是幅度比在的β-Ga最高先前报道的值更高的几乎2个数量级₂ ö ₃系光检测器，向我们所知。我们认为，显示出的β-Ga ₂ ö ₃ / MgO比异质结构，其容易制造方法相结合，将铺平用于利用基于氧化物的宽带隙材料超灵敏DUV光检测器的发展的方式。