Graphene–semiconducting light absorber hybrid photodetectors have attracted increasing attention because of their ultrahigh photoconductive gain and superior sensitivity. However, most graphene-based hybrid photodetectors reported previously have shown a relatively long response time (on the order of seconds) caused by numerous long-lived traps in these hybrid systems, which greatly restricts device speed. In this work, graphene–thieno[3,4-b]thiophene/benzodithiophene polymer hybrid photodetectors fabricated on self-assembled-monolayer (SAM)-functionalized SiO₂ substrates are demonstrated with a maximum responsivity of ∼1.8 × 10⁵ A W^–1 and a relatively short photocurrent response time of ∼7.8 ms. The fast and highly sensitive device characteristics provide great potential in low-light imaging applications. The hybrid photodetector on the SAM-coated SiO₂ substrate shows better performance in responsivities and response times as compared with those of the device on the bare SiO₂ substrate. The improved responsivities are attributed to a significant increase in carrier mobility in graphene channels by introducing SAM-modified substrates. In addition, SAM functionalization is capable of effectively removing multiple surface traps and charged impurities between graphene sheets and SiO₂ substrates, which prevents the long-lived trapping of photocarriers at graphene/SiO₂ interfaces and remarkably decreases device response time.

中文翻译：

---

具有毫秒响应时间的高灵敏度石墨烯-半导体聚合物混合光电探测器

石墨烯-半导体光吸收剂混合光电探测器因其超高的光电导增益和出色的灵敏度而引起了越来越多的关注。但是，先前报道的大多数基于石墨烯的混合光电探测器显示出相对较长的响应时间（以秒为单位），这些响应时间是由这些混合系统中的许多长寿命陷阱导致的，这极大地限制了设备速度。在这项工作中，展示了在自组装单层（SAM）功能化的SiO ₂衬底上制造的石墨烯–噻吩并[3,4- b ]噻吩/苯并二噻吩聚合物杂化光电探测器，其最大响应率为〜1.8×10 ⁵ AW ^–1相对较短的光电流响应时间约为7.8 ms。快速和高度灵敏的设备特性为弱光成像应用提供了巨大的潜力。与在裸露的SiO ₂基板上的器件相比，在SAM涂覆的SiO ₂基板上的混合光电探测器在响应度和响应时间方面表现出更好的性能。改善的响应性归因于通过引入SAM改性的底物，石墨烯通道中载流子迁移率显着提高。此外，SAM功能化能够有效去除石墨烯片和SiO ₂衬底之间的多个表面陷阱和带电杂质，从而防止了光载流子在石墨烯/ SiO _2上的长期捕获。 接口，显着减少了设备响应时间。