应变对单层碘化铅的能带及光电导率影响的第一性原理研究

First-principle Study on Effects of Strain on Band Structure and Photoconductivity of Monolayer PbI_2

采用基于密度泛函理论(DFT)的第一性原理平面波赝势方法,研究了双轴拉应变下碘化铅单层晶体的电子结构和光电导性质。结果显示,其禁带宽度随拉应变增加而略呈线性下降趋势。对应变引起的光电导率的变化进行分析,表明双轴应变能使光电导的峰值略微红移。进一步分析了单层碘化铅晶体的能态密度,解释了单层碘化铅晶体能带结构改变的机制。

The electronic and photoconductivity properties of monolayer lead iodide with biaxial tensile strain have been studied by first-principle method of plane wave potential technique based on the density function theory （DFT）. It is found that the band gap decreases slightly but linearly with increasing tensile strain. Investigations of strain effects on photoconductivity reveal that biaxial stresses lead to inconspicuous red-shift of the peak value. The mechanism of the change in band structures is explained in terms of the density of states for monolayer PbI2.