High-performance MoSe₂ homojunction infrared photodetector

Two-dimensional (2D) materials with unique structural and physical properties are urgent to exploit and may be applied in the next-generation electronics and infrared detectors. The homojunction devices are ideal and promising candidates compared to heterojunction devices since there are no interface problems, such as unintentionally induced impurities and charge-trapped sites. In this work, we reported a high-performance MoSe₂ homojunction infrared photodetector. MoSe₂ homojunction devices directly consist of thick and thin MoSe₂. MoSe₂ homojunction diodes exhibit different rectified characteristics including forward and reverse rectifications, which are dependent on the back-gate voltage. Remarkably, MoSe₂ homojunction photodetectors possess a broadband photoresponse with the wavelength from visible to near-infrared at room temperature. The responsivity of MoSe₂ homojunction photodetectors under 940 nm laser illumination is approximately 2.25 A W⁻¹. Additionally, the obtained specific detectivity of MoSe₂ homojunction device is over 10¹⁰ Jones. Our findings provide an excellent way to fabricate feasible homojunction devices. Meanwhile, homojunction devices also show the wealthy potential in novel electronic and optoelectronic devices.