Institute of Laser & Opto-electronics, College of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People's Republic of China. Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072, People's Republic of China.
Nanotechnology. 2017 Apr 7;28(14):145201. doi: 10.1088/1361-6528/aa5faf. Epub 2017 Feb 10.
A field-effect phototransistor based on a graphene and lead sulfide quantum dot (PbS QD) hybrid in which PbS QDs are embedded in a graphene matrix has been fabricated with a vertical architecture through a solution process. The n-type Si/SiO substrate (gate), Au/Ag nanowire transparent source electrode, active layer and Au drain electrode are vertically stacked in the device, which has a downscaled channel length of 250 nm. Photoinduced electrons in the PbS QDs leap into the conduction band and fill in the trap states, while the photoinduced holes left in the valence band transfer to the graphene and form the photocurrent under biases from which the photoconductive gain is evaluated. The graphene/QD-based vertical phototransistor shows a photoresponsivity of 2 × 10 A W, and specific detectivity up to 7 × 10 Jones under 808 nm laser illumination with a light irradiance of 12 mW cm. The solution-processed vertical phototransistor provides a new facile method for optoelectronic device applications.
基于石墨烯和硫化铅量子点（PbS QD）杂化的场效应光电晶体管，其中 PbS QD 嵌入在石墨烯基质中，通过溶液处理以垂直结构制造。n 型 Si/SiO 衬底（栅极）、Au/Ag 纳米线透明源电极、活性层和 Au 漏电极在器件中垂直堆叠，其缩小的沟道长度为 250nm。PbS QD 中的光致电子跃迁至导带并填充在陷阱态中，而价带中留下的光致空穴转移到石墨烯中，并在偏压下形成光电流，从中可以评估光电导增益。基于石墨烯/QD 的垂直光电晶体管在 808nm 激光照射下表现出 2×10 A W 的光响应度，在光照度为 12mW cm 的情况下，特定探测率高达 7×10 琼斯。溶液处理的垂直光电晶体管为光电设备应用提供了一种新的简便方法。
