为了研究4H—SiC晶体在强激光辐照下电子特性及其变化, 采用基于密度泛函微扰理论的第一性原理赝势的方法, 对纤锌矿4H—SiC晶体在强激光照射下的电子特性的变化进行了理论分析和实验验证。结果表明, 电子温度Te在0eV～2.75eV范围内时, 4H—SiC仍然是间接带隙的半导体晶体;当电子温度Te升高达到并超过3.0eV以上时, 4H—SiC变为直接带隙的半导体晶体;电子温度Te在0eV～2.0eV变化时, 带隙值随电子温度升高而增大; 电子温度Te在2.0eV～3.5eV变化时, 带隙值随电子温度Te的升高而迅速地减小;当电子温度Te高于3.5eV以后, 带隙已经消失而呈现出金属特性。该研究对制作4H—SiC晶体特殊功能电子元件是有帮助的。

In order to investigate the electronic properties of 4H—SiC crystal under high power laser irradiation, the first principles with pseudo potential method based on density functional perturbation theory was applied to theoretically analyze and experimentally verify the electronic properties of wurtzite 4H—SiC crystal under the strong laser irradiation. The results indicate that 4H—SiC remains semiconductor with indirect band-gap in the range of 0eV～2.75eV. When the electronic temperature reaches above 3.0eV, the crystal turns to be semiconductor with direct band-gap. The forbidden bandwidth increases with the rising of Te in the range of 0eV and 2.0eV, and the forbidden bandwidth quickly reduces with the rising of Te in the range of 2.0eV～3.5eV. When Te is over 3.5eV, the gap has disappeared and metallic properties are presented. The study will be helpful for making special function electronic components of 4H—SiC crystal.