自洽法计算非晶硅的带隙态密度

Calculation of Density of Gap States of Amorphous Silicon with Self-Consistent Method

本文叙述了一个场效应电导测量氢化非晶硅(a—Si:H)带隙态密度的数据处理方法。该法放弃了对空间电荷区电荷、电场和电势分布的任何假设,采用电子占据局域态的费米统计分布和占据扩展态的玻耳兹曼分布,应用自洽的原理,能够在较大的能量范围内计算出a-Si:H的带隙态密度分布,运算过程中以电势V为自变量,减少了对电势、电场和电荷密度等量空间分布的计算,简化了分析,提高了精度,减少了运算量。应用该法计算出了a—Si:H样品的带隙态密度在费米能级以上0.1eV到0.45 eV能量范围内的分布,它的最小值在费米能级附近,约为10^(16)cm^(-3)·eV^(-1)。

A datum processing method is described forde termining the density of gapstates of hydrogenated amorphoussilicon (a--Si: H)from field-effect conductance measurement. Inthis method, no assumptions are made about distributions of theelectric charge, field and potential in spacecharge area. It canbe usd in large energy region to compute the gap state densityof a--Si: H, with the Fermi distribution function in localizedstates and Boltzman distribution function in expanded states andthe principle of self-consistent method used. Quantity of calcul-ation is reduced and analysis is simplified by using electric pot-ential as independent variable. The distribution of gap state density within the energy regionof 0.1 eV to 0.45 eV above Fermi level has been computed with thismethod.The minimum is about 10^(16). cm^(-3) eV^(-1), near Fermi level.