Nonvolatile Engineering in 2D Bi ₂ O ₂ Se Based on Lithium Niobate

Abstract Bi 2 O 2 Se has emerged as a promising 2D material for nanoscale electronic and multifunctional optoelectronic devices, owing to its distinct native semiconductor/dielectric interface and efficient light‐to‐electric conversion capabilities. However, photodetectors based on Bi 2 O 2 Se have demonstrated both volatile and nonvolatile behaviors in previous studies, yet the underlying mechanisms remain unclear, as well as achieving controllable switching between these two states remains a significant challenge. This study presents the development of Bi 2 O 2 Se‐based optoelectronic devices, incorporating systematic investigations into the correlation between nonvolatile characteristics and multiple operational parameters. Through comprehensive analysis of fabrication processes, substrate interactions, sample dimensional control, bias voltage modulation, and incident power optimization, it is established that the intrinsic nonvolatility originates from heat‐induced bolometric effect, and the heat accumulation and dissipation process is affected by both the light illumination and concurrent electric Joule heating. Notably, the organic remnants after the photolithography process not only serve as localized thermal capacitors but also exhibit lens‐like optical focusing properties, which enable effective amplification of the intrinsic bolometric effect and achieve the transition from volatility to nonvolatility. This work presents a crucial insight into the nonvolatile engineering of 2D Bi 2 O 2 Se, advancing its potential for neuromorphic optoelectronics and adaptive photonic systems.