First-Principles Study on Strain-Regulated Thermal Transport Properties and Electronic Properties of Semiconductor Sc₂CT₂ (T = F, OH)

MXene materials are a class of two-dimensional transition-metal carbides and nitrides, which have attracted significant attention due to their unique electronic and thermal properties. In this study, we employed first-principles calculations based on the Boltzmann transport equation to investigate the phonon thermal transport and electronic properties of monolayer Sc 2 CT 2 (T = F, OH) under biaxial strains ranging from −2% to 6%. The results demonstrate that the lattice thermal conductivity of both monolayer Sc 2 CT 2 variants exhibits a distinct strain dependence, decreasing with increasing tensile strain and increasing under compressive strain. Surprisingly, the thermal conductivity of Sc 2 CF 2 increased by 51.24% under 2% compressive strain, while that of Sc 2 C(OH) 2 only showed a slight increase under compressive strain. Subsequent detailed analysis in terms of phonon specific heat, phonon group velocity, and phonon lifetime revealed that the increase in thermal conductivity of Sc 2 CF 2 is attributed to the collective enhancement of phonon specific heat, group velocity, and lifetime. In contrast, the impact of strain on the thermal conductivity of Sc 2 C(OH) 2 is primarily manifested in the low-frequency phonons. Additionally, this study analyzed the electronic localization function and band structure of Sc 2 CT 2 . Strain not only influences the electronic band structure of Sc 2 CT 2 but also alters the distribution of electronic states, thereby affecting the material’s electronic mobility. These changes in electronic properties offer new insights into the optoelectronic applications of Sc 2 CT 2 under strain control, providing significant guidance for the future design and optimization of MXene-based electronic and optoelectronic devices.