Gate- and Light-Tunable Negative Differential Resistance with High Peak Current Density in 1T-TaS₂/2H-MoS₂ T-Junction

Abstract

Metal-based electronics is attractive for fast and radiation-hard electronic circuits and remains one of the longstanding goals for researchers. The emergence of 1T-TaS 2 , a layered material exhibiting strong charge density wave (CDW) driven resistivity switching that can be controlled by an external stimulus such as electric field and optical pulses, has triggered a renewed interest in metal-electronics.Here we demonstrate a negative differential resistor (NDR) using electrically driven CDW phase transition in an asymmetrically designed T-junction made up of 1T-TaS 2 /2H-MoS 2 van der Waals heterostructure. The principle of operation of the proposed device is governed by majority carrier transport and is distinct from usual NDR devices employing tunneling of carriers, thus avoids the bottleneck of weak tunneling efficiency in van der Waals heterojunctions. Consequently, we achieve a peak current density in excess of 10 5 nAµm −2 , which is 1 arXiv:2005.07146v1 [cond-mat.mes-hall] 14 May 2020 about two orders of magnitude higher than that obtained in typical layered material based NDR implementations. The peak current density can be effectively tuned by an external gate voltage as well as photo-gating. The device is robust against ambiance-induced degradation and the characteristics repeat in multiple measurements over a period of more than a month. The findings are attractive for the implementation of active metal-based functional circuits.

Modulation of Negative Differential Resistance in Black Phosphorus Transistors

“…As discussed above, the peak current and V Peak are mainly associated with the position of minimal carrier density point. This unique temperature‐dependent property is different from the previously reported molecular devices [ 25 ] and 2D heterostructure tunneling devices [ 2–4,26,27 ] since their NDR behavior became more pronounced at lower temperature.…”

Evidence for a thermally driven charge-density-wave transition in 1T-TaS2 thin-film devices: Prospects for GHz switching speed

“…Charge-density wave (CDW) phenomena have recently witnessed renewed interest, particularly in the context of two-dimensional (2D) van der Waals materials. [1][2][3][4][5][6][7][8] This interest is driven by both exciting physics, and possible practical applications, that can be derived from such materials.…”

Recent Progress on the Scanning Tunneling Microscopy and Spectroscopy Study of Semiconductor Heterojunctions

“…However, with the help of STM, the trap states can be introduced more precisely, [ 134,135 ] which may find applications in negative differential resistance devices. [ 136,137 ] For instance, PbS/( p ‐type etched) InP with interfacial trapping states are employed in neuromorphic computing through a STM circuit based on single‐electron tunneling, acting as both synapses (weighted connections) and spiking elements. [ 138 ] The conventional Si‐based metal‐oxide‐semiconductor field‐effect transistor (MOSFET) subthreshold swing is limited by the 60 mV dec −1 , which originates from thermal carrier injection.…”