Photodetector for mid-infrared applications using few-layer vanadium carbide MXene

Here, we present a vanadium carbide (V₂C) mid-infrared (mid-IR) photodetector. Drop casting and spin coating a silicon substrate with a thin silicon oxide layer produced the V2C photodetector. Isopropyl alcohol and nitrogen gas drying increased material quality. E-beam lithography and metal deposition of Au/Ti contacts on V₂C flakes carefully made electrical connections. Electrical bias and 2 μm laser light evaluated the V₂C photodetector's dark current and photocurrent responses. Photocurrent response changed dramatically, matching FTIR spectroscopy findings. V₂C's peak responsivity of 2.65 A/W demonstrated mid-IR photodetection. To test scalability, we created devices with 2-5 μm channels. For specialized sensing, photocurrent increases with channel length. Onchip waveguides and photonic circuits might use V2C photodetectors. V₂C's mid-IR photodetector exhibits its promise as a cutting-edge optoelectronics and integrated photonics material. This work expands mid-IR-sensing photodetector technology.