Temperature‐Dependent Phase Transition in WS₂ for Reinforcing Band‐to‐Band Tunneling and Photoreactive Random Access Memory Application

Abstract

In the era of big data, negative differential resistance (NDR) devices have attracted significant attention as a means of handling massive amounts of information. While 2D materials have been used to achieve NDR behavior, their intrinsic material characteristics have produced limited performance improvements. In this article, a facile phase modification method is presented via a plasma‐assisted sulfidation process to synthesize multiphased WS2 thin films, including distorted 1 T (D‐1 T) phase and 2 H phases for photoreactive NDR devices with p‐Si. The D‐1 T phase offers a feasible route to achieve high‐performance NDR devices with excellent stability and semimetallic properties. A comprehensive investigation of experimental and computational analyses elucidates the phase transition mechanism with various temperatures and electrical properties of D‐1 T WS2. In addition, optimizing electron tunneling in the multiple‐phased tungsten disulfide (MP‐WS2)/p‐Si heterojunction at MP‐WS2 with 77.4% D‐1 T phase results in superior NDR performance with a peak‐to‐valley current ratio of 13.8 and reliable photoreactive random‐access memory. This unique phase engineering process via plasma‐assisted sulfidation provides a pioneering perspective in functionalization and reliability for next‐generation nanoelectronics.

Nanoristors: highly uniform, sub-500-millivolt, large-scale, and robust molybdenum disulfide nanograined memristors

“…To induce reliable CF formation, we initially synthesized MoS 2 layers via a cold plasma-based sulfurization process to produce several nanometer-sized grain boundaries. 26,27 The proposed metal layer sulfidation method was conducted by exposing the Mo metal layer to H 2 S + Ar plasma for 1.5 hours, as shown in Fig. 1(a).…”