Black Phosphorus/Molybdenum Diselenide Heterojunction-Based Photodetector

In this study, we report the electrical and optoelectronic performance of two-dimensional (2D) molybdenum diselenide (MoSe₂) and its heterojunction with black phosphorus (BP). BP, MoSe₂, and the heterojunction BP/MoSe₂ showed contact with gold electrodes, respectively demonstrating ohmic, Schottky, and p-n diode-like behavior with an ideality factor of 0.36 and an \({I}_{\mathrm{O}\mathrm{N}}/{I}_{\mathrm{O}\mathrm{F}\mathrm{F}}\) current ratio of approximately 10. The heterojunction (BP/MoSe₂) showed slightly better performance compared with that of 2D multilayered MoSe₂, with almost stable photoresponsivity and specific detectivity at negative bias voltage. The photoresponsivity, external quantum efficiency, normalized photocurrent-to-dark current ratio, and specific detectivity were measured as 3.2 mAW^‒1, 31.4 × 10¹² W^‒1, 0.74%, and 1.4 × 10⁹ cmHz^1/2W^‒1, respectively, at a bias voltage of ‒0.25 V. The BP/MoSe₂ heterojunction showed a photovoltaic effect with a V_CO of 0.16 V and I_SC of 14.4 nA under illumination at a wavelength of 532 nm and power of 12.36 µW. The BP/MoSe₂ heterojunction, reported in this study, can be used as self-powered photodetector.