Gate Tunable Self-Biased Diode Based on Few Layered\nMoS₂ and WSe₂

Abstract

The\noperation of a self-biased diode (SBD) based on MoS₂ has\nbeen demonstrated by using an asymmetric top gate comprising\nmetal-hexagonal boron nitride (h-BN)-MoS₂ structure. The\nrectification is achieved by asymmetric modulation of effective Schottky\nbarrier and carrier density in the channel during forward and reverse\nbias, and a rectification factor of 1.3 × 10⁵ is achieved\nin <i>I–V</i> characteristics. The modulation of\neffective Schottky barrier is verified by temperature dependent measurement\nin a range of 173 to 373 K, and a difference of 300 meV is observed\nin effective Schottky barrier height for forward and reverse bias.\nThe electrical characteristics of SBD exhibit close resemblance with\nan ideal thermionic emission model with an ideality factor of 1.3.\nSBD also exhibits strong photoelectrical response with a specific\ndetectivity of 150 A/W and responsivity of 2.1 × 10¹⁰ Jones under 450 nm laser light illumination. In the end, to demonstrate\nthe diversity of the proposed scheme, SBD based on WSe₂ has also been fabricated and the results have been discussed. These\nresults suggest a new route toward the SBD based numerous electronics\nand optoelectronics applications and can in principle be implemented\nusing other two-dimensional materials as well.