论文标题
SNO2的电子和孔迁移率来自全频段电子音波和电离杂质散射计算
Electron and Hole Mobility of SnO2 from Full-Band Electron-Phonon and Ionized Impurity Scattering Computations
论文作者
论文摘要
迁移率是SNO2的关键参数，该参数被广泛研究为实用的透明氧化物N型半导体。在实验中，在室温下，散装SNO2单晶电子中电子的迁移率在70至260 cm2v-1s-1之间变化。在这里，我们通过将Boltzmann传输方程与密度函数理论电子结构耦合，从电子音波和电离杂质散射限制的迁移率。线性化的玻尔兹曼传输方程通过考虑散射速率的所有能量和动量依赖性，从数值上求解了通常使用的恒定松弛时间近似。对于电子形声散射，认为声音变形电位和极性声子被认为，其中极性声子散射是决定室温下电子和孔的迁移率的主要因素。发现计算出的声子限制的电子迁移率为265 cm2v-1s-1，而孔的迁移率为7.6 cm2v-1s-1。我们将迁移率与载流子浓度的函数表示，该载体浓度显示了上部迁移率极限。 N型和P型SNO2的迁移率之间的巨大差异是电子和孔之间不同有效质量的结果。
Mobility is a key parameter for SnO2, which is extensively studied as a practical transparent oxide n-type semiconductor. In experiments, the mobility of electrons in bulk SnO2 single crystals varies from 70 to 260 cm2V-1s-1 at room temperature. Here, we calculate the mobility as limited by electron-phonon and ionized impurity scattering by coupling the Boltzmann transport equation with density functional theory electronic structures. The linearized Boltzmann transport equation is solved numerically beyond the commonly employed constant relaxation-time approximation by taking into account all energy and momentum dependencies of the scattering rates. Acoustic deformation potential and polar optical phonons are considered for electron-phonon scattering, where polar optical phonon scattering is found to be the main factor which determines the mobility of both electrons and holes at room temperature. The calculated phonon-limited electron mobility is found to be 265 cm2V-1s-1, whereas that of holes is found to be 7.6 cm2V-1s-1. We present the mobility as a function of the carrier concentration, which shows the upper mobility limit. The large difference between the mobilities of n-type and p-type SnO2 is a result of the different effective masses between electrons and holes.
