Ga₂O₃ based self-powered photodetectors, which can work in photovoltaic mode, show great potential applications in the next-generation photodetectors. Due to the difficulty of p-type doping of Ga₂O₃, constructing heterojunctions is a promising alternative for self-powered Ga₂O₃ photodetectors. Although several inorganic materials have been focused on fabricating Ga₂O₃ based heterojunction, some disadvantages prevent them from being widely used, such as the large lattice mismatch, the unsuitable bandgap, the inflexibility, the complex preparation process, etc. In this study, a general strategy has been proposed for high-performance photodetectors through building a type-Ⅱ Ga₂O₃ heterojunction with the small-molecule hole transport materials (SMHTMs). The relatively large hole mobility of SMHTMs guarantees the high-speed transport of the photogenerated holes, and the solar-blind filter effect of the SMHTMs films makes the photodetector highly spectrum selective. Herein, four types of SMHTMs have been used to constructed photodetectors with Ga₂O₃, and all of them exhibit self-powered characteristics with I_on/I_off ratios of about>10⁵, which is 1–2 orders of magnitude larger than these previously reported Ga₂O₃ photodetectors. Among them, the photodetector based on β-Ga₂O₃/TAPC heterojunction shows the best photoelectrical performances with a dark current of about 20 fA, a I_on/I_off ratio of 5.9 × 10⁵, and a detectivity of 1.02 × 10¹³ Jones at 0 V, all of which are amongst the best values ever reported for Ga₂O₃ based self-powered photodetectors. The high-speed transport of the photogenerated holes and large built-in field in the β-Ga₂O₃/SMHTMs heterojunctions should be responsible for these remarkable performances. This work provides a feasible strategy to high-performance Ga₂O₃ based self-powered photodetectors, thus may push forward their applications.

基于Ga ₂ O ₃的自供电光电探测器可以在光伏模式下工作，在下一代光电探测器中显示出巨大的潜在应用。由于Ga ₂ O ₃的p型掺杂困难，构建异质结是自供电Ga ₂ O ₃光电探测器的有希望的替代方案。尽管有几种无机材料已专注于制造 Ga ₂ O ₃基于异质结的一些缺点阻碍了它们的广泛应用，例如大的晶格失配、不合适的带隙、不灵活、制备过程复杂等。在本研究中，通过构建高性能光电探测器提出了一种通用策略具有小分子空穴传输材料（SMHTMs）的Ⅱ型Ga ₂ O _{3异质结。}SMHTMs相对较大的空穴迁移率保证了光生空穴的高速传输，SMHTMs薄膜的日盲滤光效应使光电探测器具有高光谱选择性。在此，四种类型的 SMHTM 已用于构建具有 Ga ₂ O _{3的光电探测器}，并且它们都表现出自供电特性，I _on / I _off比约为> 10 ⁵，比这些先前报道的Ga ₂ O ₃光电探测器大1-2个数量级。其中，基于β - Ga ₂ O ₃ /TAPC异质结的光电探测器表现出最好的光电性能，暗电流约为20 fA，I _on / I _off比为5.9 × 10 ⁵，检测率为1.02 × 10 ^{13 Jones 在 0 V，所有这些都是 Ga} ₂报告的最佳值之一基于O ₃的自供电光电探测器。光生空穴的高速传输和β -Ga ₂ O ₃ /SMHTMs 异质结中的大内建场应该是这些显着性能的原因。_{该工作为基于Ga 2} O ₃的高性能自供电光电探测器提供了一种可行的策略，从而可能推动其应用。