Dual Mode Optoelectronic Devices Based on 2D Single Crystalline VO₂ Films with Controlled Metallic Domain Regime Induced Variable Hysteresis

The multimode optoelectronic operation in a single component device is an attractive design strategy for future optoelectronics, which demands unique and complex multifunction. Here, a novel dual-mode optoelectronic device with both memory and switching functionalities by utilizing alternating metallic stripe domain regime-induced controllable hysteresis of two dimensional (2D)-crystalline VO₂ films is reported. It is found that the formation and disappearance of tensile strain-induced metallic stripe domain arrays are susceptible to temperature-induced thermal energy, allowing controllable hysteresis in electric field-induced metal-insulator transition (E-MIT) by tuning the total region of aligned metallic stripe domains within the VO₂ films through current flow-induced thermal energy. Based on the tunable hysteresis in E-MIT, the 2D-crystalline VO₂ film-based device exhibits successful multimode optoelectronic memory and switching operations. The device with a large hysteresis width exhibits high-performance optoelectronic memory behavior with a high on/off ratio of up to ≈55% and a long retention time over 5000 s response to a light pulse optically triggering MIT. On the other hand, the 2D-crystalline VO₂ film device with a narrow hysteresis width exhibits high performance of photodetection with a responsivity of 316 mA W⁻¹ and response times of ≈1.2 and ≈2 µs at rise and fall, respectively.