Fig. 1: Structure of TaS2 material and phase transition phenomena induced by external conditions.
From: Reconfigurable terahertz optoelectronic logic through charge-density-wave phase engineering
a Layered side view of TaS2 material. b Structural diagram of the phase transition in TaS2 material. c The structure of Star-of-Daid. d Charge Transfer Analysis in 1T-TaS2. e Optical image of a two-probe 1T-TaS2 device. One electrode is grounded (GND) and the other was used to apply the voltage (V). f Temperature-electric field phase diagram of 1T-TaS2 nanodevice, illustrating the resistance evolution across the NC-CDW to IC-CDW phase transition. g Temperature-dependent current-electric field characteristics of 1T-TaS2 measured from 77 K to 300 K, revealing three distinct electronic phases: supercooled NC-CDW (sc-NC-CDW) at low fields, NC-CDW at intermediate fields, and IC-CDW at high fields. The threshold electric field for the NC-CDW to IC-CDW transition exhibits pronounced temperature dependence, increasing systematically with decreasing temperature, reflecting enhanced CDW phase stability at lower temperatures. h Triangular diagram illustrating the combined effect of environmental temperature T, electric field E, and light intensity U on the phase transition of 1T-TaS2. The color gradient represents the electron temperature Te, which is determined by T, E, and U as Te = f(T,E,U). The free energy difference ΔG driving the phase transition is influenced by Te. Below the threshold Te < Te−th, 1T-TaS2 remains in the IC-CDW phase; above Te > Te−th, it transitions to the NC-CDW phase.
