GaInX₃（X = S, Se, Te）:Ultra-low thermal conductivity and excellent thermoelectric performance

【摘要】 Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric materials.Here,by using first-principles calculations and semiclassical Boltzmann transport theory,we systemically investigate the carrier transport and thermoelectric properties of monolayer Janus GaInX₃（X=S,Se,Te）.It is found that the lattice thermal conductivities can reach values as low as 3.07 W·m^-1·K^-1,1.16 W·m^-1·K^-1 and 0.57 W·m^-1·K^-1for GaInS₃,GaInSe₃,and GaInTe₃,respectively,at room temperature.This notably low thermal conductivity is attributed to strong acoustic-optical phonon coupling caused by the presence of low-frequency optical phonons in GaInX₃ materials.Furthermore,by integrating the charac teristics of electronic and thermal transport,the dimensionless figure of merit ZT can reach maximum values of 0.95,2.37,and 3.00 for GaInS₃,GaInSe₃,and GaInTe₃,respectively.Our results suggest that monolayer Janus GaInX₃（X=S,Se,Te） is a promising candidate for thermoelectric and heat management applications.更多还原

【Abstract】 Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric materials.Here,by using first-principles calculations and semiclassical Boltzmann transport theory,we systemically investigate the carrier transport and thermoelectric properties of monolayer Janus GaInX₃（X=S,Se,Te）.It is found that the lattice thermal conductivities can reach values as low as 3.07 W·m^-1·K^-1,1.16 W·m^-1·K^-1 and 0.57 W·m^-1·K^-1for GaInS₃,GaInSe₃,and GaInTe₃,respectively,at room temperature.This notably low thermal conductivity is attributed to strong acoustic-optical phonon coupling caused by the presence of low-frequency optical phonons in GaInX₃ materials.Furthermore,by integrating the charac teristics of electronic and thermal transport,the dimensionless figure of merit ZT can reach maximum values of 0.95,2.37,and 3.00 for GaInS₃,GaInSe₃,and GaInTe₃,respectively.Our results suggest that monolayer Janus GaInX₃（X=S,Se,Te） is a promising candidate for thermoelectric and heat management applications.更多还原