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 cmHz1/2W‒1, respectively, at a bias voltage of ‒0.25 V. The BP/MoSe2 heterojunction showed a photovoltaic effect with a VCO of 0.16 V and ISC 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.