Charge-Density Wave Driven Giant Thermionic-Current Switching in 1T-TaS$_{2}$/2H-TaSe$_{2}$/2H-MoS$_{2}$ Heterostructure

TL;DR

This study demonstrates a giant thermionic-current switching in a heterostructure driven by charge-density wave phase transitions and associated temperature changes, with potential applications in neuromorphic and electronic devices.

Contribution

It introduces a novel heterostructure device leveraging charge-density wave-induced temperature changes for large current switching, surpassing previous resistivity change limitations.

Findings

Achieved 964-fold current switching in MoS2 channel.

Exploited phase transition-induced temperature change for carrier promotion.

Device shows high reconfigurability and abrupt current reduction.

Abstract

1T-TaS$_2$ exhibits several resistivity phases due to the modulation of charge density wave (CDW). The fact that such phase transition can be driven electrically has attracted a lot of attention in the recent past towards \emph{active-metal} based electronics. However, the bias-driven resistivity switching is not very large ($<$ 5 fold), and an enhancement in the same will highly impact such phase transition devices. One aspect that is often overlooked is that such phase transition is also accompanied by a significant change in the local temperature due to the low thermal conductivity of 1T-TaS$_2$. In this work, we exploit such electrically driven phase transition induced temperature change to promote carriers over a thermionic barrier in a 1T-TaS$_{2}$/2H-TaSe$_{2}$/2H-MoS$_{2}$ T-Junction, achieving a $964$-fold abrupt switching in the current through the MoS$_2$ channel. The device is highly reconfigurable and exhibits an abrupt reduction in current as well when the biasing configuration changes. The results are promising for several electronic applications, including neuromorphic chips, switching, nonlinear devices, and industrial electronics such as current and temperature sensing.