Thermoelectric Properties Of Two-dimensional InX Materials

Energy problem has become an important issue in the world.The current global energy market is transforming,and the urgent need for efficient and pollution-free new energy is increasingly.Two-dimensional(2D)materials have shown great potential for thermal management and thermoelectric(TE)energy generation due to their fascinating electrical and thermal transport properties.Recently,experimental and theoretical studies on single layers of III-V materials have stimulated enormous interest in exploring the thermoeletric properties of these materials.Furthermore,the two-dimensional III-VI materials have already had a more mature experimental basis,and Indium selenide has become a research hotspot in recent years.The main contents of this paper are as follows:(1)We present a theoretical investigation of the thermoelectric properties of monolayer In-VA.Firstly,the influence of structure on electronoic properties is analyzed.Based on the boltzmann transport theory and relaxation time approximation method,the transport properties of single layer In-VA are studied.The ultralow intrinsic thermal conductivities of 2.64 Wm-1K-1(InP),1.31 Wm-1K-1(InAs),0.87 Wm-1K-1(InSb)and 0.62 Wm-1K-1(InBi)evaluated at room temperature are close to typical thermal conductivity of good TE materials(k<2 Wm-1K-1).The maximal ZT values of 0.779,0.583,0.696,0.727 and 0.373 for InN,InP,InAs,InSb and InBi are calculated at high temperature 900K,which makes In-VA potential TE materials working at medium-high temperature.(2)The thermoelectric properties of 2D InSe compound are investigated.Under our calculation,the action of spin orbit coupling(SOC)and biaxial stress are considered.The stability of the single-layer InSe is determined under the stress of 0%-10%;thermoelectric properties of InSe under stress modulation are also considered.Under the stress of 2%,the lattice thermal conductivity of InSe decreases significantly,from the strain-less state of 1.2 to 0.89,where the temperature is 300K;at the temperature of 600K,the maximum ZT value of InSe increases from 0.81 to 1.18.Our research proves that appropriate stress is favor for improvement of thermoelectric figure of merit of the two-dimensional materials.