Probing the Temperature-Dependent Thermal Conductivity of Violet Phosphorus via Optothermal Raman Spectroscopy

The temperature-dependent thermal conductivity of violet phosphorus on a perforated SiO₂/Si substrate has been investigated via optothermal Raman spectroscopy. The obtained temperature coefficients of the Tg mode and P_tub mode of the violet phosphorus sample are −0.01268 and −0.01789 cm^-1 K^-1, respectively. On the basis of the temperature coefficients and power coefficients, the thermal conductivity of the violet phosphorus has been calculated to be 44.642 ± 4.995 W/mK at room temperature, which is higher than that of other two-dimensional materials such as black phosphorus and MoS₂ due to the effect of boundary scattering and the phonon mean free path. Additionally, the thermal conductivity of violet phosphorus decreases as a power exponential function of the temperature, which is primarily associated with the phonon mean free path and phonon group velocity. This work provides a scientific foundation for thermal management and heat dissipation in designing micro-nano devices with violet phosphorus.