Interfacial Engineering of In<sub>2</sub>Se<sub>3</sub>/h-BN/CsPb(Br/I)<sub>3</sub> Heterostructure Photodetector and Its Application in Automatic Obstacle Avoidance System
Yingying Niu, Xin Zhou, Wei Gao, Maixia Fu, Yule Duan, Jiandong Yao, Bing Wang, Mengmeng Yang, Zhaoqiang Zheng, Jingbo Li
Abstract
Driven by the rapid development of autonomous vehicles, ultrasensitive photodetectors with high signal-to-noise ratio and ultraweak light detection capability are urgently needed. Due to its intriguing attributes, the emerging van der Waals material, indium selenide (In 2 Se 3 ), has attracted extensive attention as an ultrasensitive photoactive material. However, the lack of an effective photoconductive gain mechanism in individual In 2 Se 3 inhibits its further application. Herein, we propose a heterostructure photodetector consisting of an In 2 Se 3 photoactive channel, a hexagonal boron nitride (h-BN) passivation layer, and a CsPb(Br/I) 3 quantum dot gain layer. This device manifests a signal-to-noise ratio of 2 × 10 6 with responsivity of 2994 A/W and detectivity of 4.3 × 10 14 Jones. Especially, it enables the detection of weak light as low as 0.03 μW/cm 2 . These performance characteristics are ascribed to the interfacial engineering. In 2 Se 3 and CsPb(Br/I) 3 with type-II band alignment promote the separation of photocarriers, while h-BN passivates the impurities on CsPb(Br/I) 3 and promises a high-quality carrier transport interface. Furthermore, this device is successfully integrated into an automatic obstacle avoidance system, demonstrating promising application prospects in autonomous vehicles.