Study On The Physical Properties Of Gallium Indium Antimony Infrared Materials Modulated By Gallium Components

The thermal management performance and optical properties of antimonide semiconductor materials can be modulated by alloying to improve the performance of materials and devices.Therefore,the thermal and optical properties of indium antimonide,gallium antimonide and their alloy Ga_xIn_1-xSb have been studied in terms of crystal structure,phonon transport and electronic properties using the first-principles calculation method based on the Density Functional of Theory and Phonon Boltzmann Transport Equation.The main results are as follows:The thermal conductivities of In Sb,Ga Sb and Ga_xIn_1-xSb alloys were calculated(x=0,κ=5.15 Wm^-1K^-1;x=0.25,κ=9.21 Wm^-1K^-1;x=0.5,κ=11.22 Wm^-1K^-1;x=0.75,κ=15.45Wm^-1K^-1;x=1,κ=50.68 Wm^-1K^-1).The special phenomenon that the thermal conductivity of alloy is higher than that of parent material is found for the first time by calculation,which is different from the traditional view that alloying will reduce the thermal conductivity of materials.Therefore,further analysis shows that the reasons for the increase of thermal conductivity of the alloy are as follows:With the increase of Ga component,the phonon group velocity and phonon relaxation time of Ga_xIn_1-xSb alloy are higher than that of parent material In Sb,and the phonon lifetime increases with the increase of phonon relaxation time,which leads to the increase of thermal conductivity.In addition,with the increase of Ga composition,the phonon anharmonicity of Ga_xIn_1-xSb alloy is weakened,so the phonon-phonon scattering intensity is reduced,and the thermal conductivity of Ga_xIn_1-xSb alloy is improved.Furthermore,influenced by the difference of radius and mass among Ga atom,In atom and Sb atom,the crystal structure of the alloy is changed.By analyzing the density of states and electron local function,it can be seen that the bond polarity and electron interaction strength of Ga_xIn_1-xSb alloy are weakened,which leads to the increase of thermal conductivity.Finally,the optical properties of Ga_xIn_1-xSb alloy were calculated and analyzed,and it was found that Ga_xIn_1-xSb alloy with high light transmittance and low energy loss can be used to prepare infrared electronic devices with high power efficiency.The effects of Ga components on the physical properties of Ga_xIn_1-xSb alloy were investigated at atomic and electronic scales,and the physical mechanism of enhancing the thermal conductivity and modulating the optical properties of Ga_xIn_1-xSb alloy by alloying was revealed,which provided theoretical guidance for the heat dissipation and luminescence design of photoelectric devices.