Catalyst‐Free Polymorphic β‐Ga2O3 Nanomaterials for Solar‐Blind Optoelectronic Devices: Applications in Imaging and Neural Communication

Abstract The continuous advancements in ultraviolet‐C (UV‐C) optoelectronics are poised to meet the growing demand for efficient and innovative optoelectronic devices, particularly in image sensing and neural communication. This study proposes a low‐cost tube sealing and muffle calcination process for the catalyst‐free synthesis of polymorphic β‐Ga 2 O 3 nanomaterials. These nanomaterials are synthesized via a vapor‐solid (VS) growth mechanism, enabling the formation of high‐quality nanowires (NWs), nanobelts (NBs), and nanosheets (NSs). UV‐C photodetectors (PDs) fabricated with β‐Ga 2 O 3 nanobelts demonstrated exceptional performance, exhibiting a responsivity of 4.62 × 10 5 A W −1 and a specific detectivity of 4.78 × 10 12 Jones under 254 nm light. This PD enabled high‐sensitivity and high‐contrast UV‐C imaging, effectively capturing the letters “CNU” and a “Panda” pattern. Additionally, the β‐Ga 2 O 3 nanowire‐based optoelectronic synapse (OES) device displayed efficient light sensing and significant persistent photoconductivity, accurately mimicking synaptic behaviors such as short‐term to long‐term memory transitions and memory reinforcement. The OES device is successfully integrated into a wireless optical communication system, effectively simulating neural signal transmission by outputting the current waveform signal of “CNU 1954” and exhibiting notable UV‐C light sensing and learning abilities. This work not only introduces a method for synthesizing polymorphic β‐Ga 2 O 3 nanomaterials but also underscores their potential in advanced UV‐C optoelectronic applications, including image sensing and neural communication.