Shen Ting, Li Bo, Zheng Kaibo, Pullerits Tönu, Cao Guozhong, Tian Jianjun
Institute for Advanced Materials and Technology , University of Science and Technology Beijing , Beijing 100083 , China.
Department of Chemical Physics and NanoLund , Lund University , Box 124, 22100 Lund , Sweden.
J Phys Chem Lett. 2018 Jun 21;9(12):3285-3294. doi: 10.1021/acs.jpclett.8b01255. Epub 2018 Jun 5.
Ternary alloyed CdSe Te colloidal QDs trap-passivated by iodide-based ligands (TBAI) are developed as building blocks for UV-NIR photodetectors. Both the few surface traps and high loading of QDs are obtained by in situ ligand exchange with TBAI. The device is sensitive to a broad wavelength range covering the UV-NIR region (300-850 nm), showing an excellent photoresponsivity of 53 mA/W, a fast response time of ≪0.02s, and remarkably high detectivity values of 8 × 10 Jones at 450 nm and 1 × 10 Jones at 800 nm without an external bias voltage. Such performance is superior to what has been reported earlier for QD-based photodetectors. The photodetector exhibits excellent stability, keeping 98% of photoelectric responsivity after 2 months of illumination in air even without encapsulation. In addition, the semitransparent device is successfully fabricated using a Ag nanowires/polyimide transparent substrate. Such self-powered photodetectors with fast response speed and a stable, broad-band response are expected to function under a broad range of environmental conditions.
基于碘化物配体（TBAI）陷阱钝化的三元合金CdSeTe胶体量子点被开发用作紫外-近红外光电探测器的构建模块。通过与TBAI进行原位配体交换，既获得了少量的表面陷阱，又实现了量子点的高负载。该器件对覆盖紫外-近红外区域（300-850nm）的宽波长范围敏感，在无外部偏置电压的情况下，显示出53 mA/W的优异光响应度、≪0.02s的快速响应时间以及在450nm处8×10 Jones和在800nm处1×10 Jones的极高探测率值。这种性能优于先前报道的基于量子点的光电探测器。该光电探测器表现出优异的稳定性，即使在空气中光照2个月且未封装的情况下，仍保持98%的光电响应度。此外，使用银纳米线/聚酰亚胺透明基板成功制造了半透明器件。这种具有快速响应速度以及稳定宽带响应的自供电光电探测器有望在广泛的环境条件下发挥作用。
