Ferroelectrically Modulated and Enhanced Photoresponse in a Self-Powered α-In<sub>2</sub>Se<sub>3</sub>/Si Heterojunction Photodetector
Cheng Jia, Shuangxiang Wu, Jinze Fan, Chaojie Luo, Minghui Fan, Ming Li, Lanping He, Yuanjun Yang, Hui Zhang
Abstract
High Resolution Image Download MS PowerPoint Slide Photodetectors have been applied to pivotal optoelectronic components of modern optical communication, sensing, and imaging systems. As a room-temperature ferroelectric van der Waals semiconductor, 2D α-In 2 Se 3 is a promising candidate for a next-generation optoelectronic material because of its thickness-dependent direct bandgap and excellent optoelectronic performance. Previous studies of photodetectors based on α-In 2 Se 3 have been rarely focused on the modulated relationship between the α-In 2 Se 3 intrinsic ferroelectricity and photoresponsivity. Herein, a simple integrated process and high-performance photodetector based on an α-In 2 Se 3 /Si vertical hybrid-dimensional heterojunction was constructed. Our photodetector in the ferroelectric polarization up state accomplishes a self-powered, highly sensitive photoresponse with an on/off ratio of 4.5 × 10 5 and detectivity of 1.6 × 10 13 Jones, and it also shows a fast response time with 43 μs. The depolarization field generated by the remanent polarization of ferroelectrics in α-In 2 Se 3 provides a strategy for enhancement and modulation of photodetection. The negative correlation was discovered because the enhancement photoresponsivity factor of ferroelectric modulation competes with the photovoltaic behavior within the α-In 2 Se 3 /Si heterojunction. Our research highlights the great potential of the high-efficiency heterojunction photodetector for future object recognition and photoelectric imaging.