Ferroelectrically Modulated and Enhanced Photoresponse in a Self-Powered Α-In2se3/si Heterojunction Photodetector

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 alpha-In2Se3 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 alpha-In2Se3 have been rarely focused on the modulated relationship between the alpha-In(2)Se(3)3 intrinsic ferroelectricity and photoresponsivity. Herein, a simple integrated process and high-performance photodetector based on an alpha-In2Se3/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 x 10(5) and detectivity of 1.6 x 10(13) Jones, and it also shows a fast response time with 43 mu s. The depolarization field generated by the remanent polarization of ferroelectrics in alpha-In2Se3 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 alpha-In2Se3/Si heterojunction. Our research highlights the great potential of the high-efficiency heterojunction photodetector for future object recognition and photoelectric imaging.