Abstract Solar-blind photodetection systems, which can convert solar-blind deep ultraviolet light into an electrical signal, have been designed for practical use owing to their high sensitivity and accuracy. As one of the most suitable semiconductors for solar-blind photodetection, β-Ga2O3 can construct a pn type photodetector with another semiconductor material to meet the demands of energy savings, miniaturization and high efficiency. As a kind of natural p-type material, delafossite semiconductor materials CuMO2 (M = Al3+, Ga3+, In3+, Cr3+) have attracted much attention recently. The band alignment of CuMO2 is staggered with that of n-type β-Ga2O3; hence, the photogenerated electrons and holes tend to transfer through the interface in the opposite directions, resulting in spatial separation of charge carriers. Meanwhile, the fast hole diffusion coefficient (10-2–101 cm2 V−1 s−1) of CuMO2 guarantees the transport of holes, which is difficult in β-Ga2O3 owing to its intrinsic electronic structure. More importantly, compared with the widely used p-type materials, CuMO2 materials are almost insensitive to UVA light owing to the forbidden intrinsic direct transitions between the conduction and valence bands. Hence, the CuMO2/β-Ga2O3 pn junction photodetector exhibits high sensitivity, and the working spectral region is not extended to the UVA region. In this study, n-β-Ga2O3/p-CuMO2 (M: Ga3+, Cr3+) pn junction photodetectors were prepared by a simple solution process method. Due to the high crystallinity of the as-grown CuGaO2 and CuCrO2, the CuGaO2/β-Ga2O3 and CuCrO2/β-Ga2O3 pn junction photodetectors demonstrate an ultralow off state current of 51/61 fA, a superhigh on-to-off state current ratio of 2.3×104/3.5×104 and a high rejection ratio (R254/R365) of 2×104/2.8×104 under a bias of 0 V. The CuMO2/β-Ga2O3 pn junction photodetector satisfies the requirements of high sensitivity, stable and energy saving and has wide practical application prospect in solar-blind detection systems.

中文翻译：

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基于CuMO2/Ga2O3 pn异质结的高灵敏稳定溶液处理全无机自供电日盲光电探测器

摘要 日盲光电探测系统可将日盲深紫外光转换为电信号，因其高灵敏度和高精度而被设计用于实际应用。作为最适合日盲光电探测的半导体之一，β-Ga2O3可以与另一种半导体材料构建pn型光电探测器，以满足节能、小型化和高效率的需求。作为一种天然的p型材料，铜铁矿半导体材料CuMO2（M=Al3+、Ga3+、In3+、Cr3+）最近备受关注。CuMO2的能带排列与n型β-Ga2O3的排列错开；因此，光生电子和空穴倾向于以相反的方向通过界面转移，导致电荷载流子的空间分离。同时，CuMO2 的快速空穴扩散系数 (10-2–101 cm2 V-1 s-1) 保证了空穴的传输，由于其固有的电子结构，这在 β-Ga2O3 中是困难的。更重要的是，与广泛使用的 p 型材料相比，CuMO2 材料由于导带和价带之间禁止的本征直接跃迁对 UVA 光几乎不敏感。因此，CuMO2/β-Ga2O3 pn 结光电探测器表现出高灵敏度，并且工作光谱区域未扩展到 UVA 区域。在这项研究中，n-β-Ga2O3/p-CuMO2 (M: Ga3+, Cr3+) pn 结光电探测器是通过简单的溶液工艺方法制备的。由于生长的 CuGaO2 和 CuCrO2 的高结晶度，CuGaO2/β-Ga2O3 和 CuCrO2/β-Ga2O3 pn 结光电探测器表现出 51/61 fA 的超低关态电流，