Institute of Optoelectronics & Nanomaterials, MIIT Key Laboratory of Advanced Display Materials and Devices, College of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
Grünberg Research Centre, Nanjing University of Posts and Telecommunications , Nanjing 210003, China.
ACS Appl Mater Interfaces. 2018 Jan 24;10(3):2801-2809. doi: 10.1021/acsami.7b14745. Epub 2018 Jan 9.
Transition metal dichalcogenides (TMDs) are promising candidates for flexible optoelectronic devices because of their special structures and excellent properties, but the low optical absorption of the ultrathin layers greatly limits the generation of photocarriers and restricts the performance. Here, we integrate all-inorganic perovskite CsPbBr nanosheets with MoS atomic layers and take the advantage of the large absorption coefficient and high quantum efficiency of the perovskites, to achieve excellent performance of the TMD-based photodetectors. Significantly, the interfacial charge transfer from the CsPbBr to the MoS layer has been evidenced by the observed photoluminescence quenching and shortened decay time of the hybrid MoS/CsPbBr. Resultantly, such a hybrid MoS/CsPbBr photodetector exhibits a high photoresponsivity of 4.4 A/W, an external quantum efficiency of 302%, and a detectivity of 2.5 × 10 Jones because of the high efficient photoexcited carrier separation at the interface of MoS and CsPbBr. The photoresponsivity of this hybrid device presents an improvement of 3 orders of magnitude compared with that of a MoS device without CsPbBr. The response time of the device is also shortened from 65.2 to 0.72 ms after coupling with MoS layers. The combination of the all-inorganic perovskite layer with high photon absorption and the carrier transport TMD layer may pave the way for novel high-performance optoelectronic devices.
过渡金属二卤化物（TMDs）因其特殊的结构和优异的性能而成为柔性光电设备的理想选择，但超薄层的低光吸收极大地限制了光生载流子的产生，限制了其性能。在这里，我们将全无机钙钛矿 CsPbBr 纳米片与 MoS 原子层集成，并利用钙钛矿的高吸收系数和高光量子效率，实现了基于 TMD 的光电探测器的优异性能。值得注意的是，通过观察到的光致发光猝灭和混合 MoS/CsPbBr 的衰减时间缩短，证明了 CsPbBr 向 MoS 层的界面电荷转移。因此，由于 MoS 和 CsPbBr 界面处高效的光激发载流子分离，这种混合 MoS/CsPbBr 光电探测器表现出 4.4 A/W 的高光响应率、302%的外量子效率和 2.5×10 的探测率。与没有 CsPbBr 的 MoS 器件相比，该混合器件的光响应率提高了 3 个数量级。在与 MoS 层耦合后，器件的响应时间也从 65.2 毫秒缩短到 0.72 毫秒。具有高光子吸收和载流子输运 TMD 层的全无机钙钛矿层的组合可能为新型高性能光电设备铺平道路。
