Two-DimensionalBi2Se3/MoSe2 Heterostructure forPhotodetection Applications

In this work, we have experimentally fabricated a MoSe2/Bi2Se3-based type-II van der Waals (vdW) heterojunction photodetector (PD) suitable for detecting optical signals between 400 and 1000 nm. This PD shows excellent performance metrics such as a peak responsivity of 13.35 A/W and a detectivity of 5.7 × 1013 Jones at 400 nm. Also, the fabricated PD exhibited an ultrahigh external quantum efficiency of 4038% at 400 nm with rise and fall times of 105 and 166 ms, respectively. The built-in potential at the heterojunction facilitated excellent separation and transport of the photogenerated electron–hole pairs through suitable energy band diagrams. Also, various Schottky diode parameters of the device have been extracted from the measured I–V characteristics. Using the modeled parameters, I–V characteristics were redrawn and compared with the measured values. Between 0 and 5 V, the modeled I–V characteristics showed minimum and maximum errors of 0.57% and 6.21%, respectively.