Joule-heating induced phase transition in 1T-TaS₂near room temperature probed by thermal imaging of power dissipation

Electrically induced phase transition in 1T-TaS2 at room temperature has various applications, including efficient oscillators and broadband photodetectors. However, the physical mechanism behind the electrically induced phase transition is still not clear due to the lack of direct temperature measurements during the transition. To shed light on this problem, in this Letter, we directly image the spatially resolved temperature of a 1T-TaS2 device by IR thermal microscopy. Combining this method with pulsed electrical transport measurements, Raman spectroscopy, and a simple resistor network model, we show that the transition is a result of Joule-heating. More broadly, we show that thermal imaging is important to determine the power dissipation in electronic devices due to the inhomogeneous nature of the temperature distribution.