Hong Seongin, Choi Seung Hee, Park Jongsun, Yoo Hocheon, Oh Joo Youn, Hwang Euyheon, Yoon Dae Ho, Kim Sunkook
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Republic of Korea.
School of Electrical Engineering, Korea University, Seoul 136-713, Republic of Korea.
ACS Nano. 2020 Aug 25;14(8):9796-9806. doi: 10.1021/acsnano.0c01689. Epub 2020 Jul 10.
Sensory adaptation is an essential part of biological neural systems for sustaining human life. Using the light-induced halide phase segregation of CsPb(BrI) perovskite, we introduce neuromorphic phototransistors that emulate human sensory adaptation. The phototransistor based on a hybrid structure of perovskite and transition-metal dichalcogenide (TMD) emulates the sensory adaptation in response to a continuous light stimulus, similar to the neural system. The underlying mechanism for the sensory adaptation is the halide segregation of the mixed halide perovskites. The phase separation under visible-light illumination leads to the segregation of I and Br into separate iodide- and bromide-rich domains, significantly changing the photocurrent in the phototransistors. The devices are reversible upon the removal of the light stimulation, resulting in near-complete recovery of the photosensitivity before the phase segregation (sensitivity recovery of 96.65% for 5 min rest time). The proposed phototransistor based on the perovskite-TMD hybrid structure can be applied to other neuromorphic devices such as neuromorphic photonic devices, intelligent sensors, and selective light-detecting image sensors.
感觉适应是维持人类生命的生物神经系统的重要组成部分。利用光诱导的CsPb(BrI)钙钛矿卤化物相分离，我们引入了模拟人类感觉适应的神经形态光电晶体管。基于钙钛矿和过渡金属二卤化物（TMD）混合结构的光电晶体管模拟了对连续光刺激的感觉适应，类似于神经系统。感觉适应的潜在机制是混合卤化物钙钛矿的卤化物分离。可见光照射下的相分离导致I和Br分离成富含碘化物和溴化物的单独区域，显著改变了光电晶体管中的光电流。去除光刺激后，器件是可逆的，导致相分离前的光敏性几乎完全恢复（5分钟休息时间的灵敏度恢复率为96.65%）。所提出的基于钙钛矿-TMD混合结构的光电晶体管可应用于其他神经形态器件，如神经形态光子器件、智能传感器和选择性光探测图像传感器。
