半導體介電函數解析模式之建立

Abstract

Driven Harmonic Oscillator (DHO)模型是以電子在原子中的運動方程式來描述其振幅大小，將此模型用於介電函數的計算，在吸收帶範圍的介電函數實部與虛部通常高於實驗值許多，因此我們提出一個以 N=2 或 N=4 次方的輻射阻尼常數取代 DHO 模型原有的阻尼係數，將 DHO 修改為 Γ-modified DHO與DHO混合的模型。並重新計算原有 DHO 模型在靠近能隙範圍的模擬，計算數個半導體材料的介電函數實部與虛部，將計算結果與實驗數值及其他模型比較，證實我們的模型能符合大範圍的實驗數值，並且改善其他模型在靠近能隙範圍計算不準確的情況。

We use the driven harmonic oscillator (DHO) model that is described the amplitude of electronic motion in the atom to calculate the dielectric function. In the region of absorption edge, the real part and imaginary part of dielectric function are higher than experimental data. Thus we propose a mixed Γ-modified DHO model that originary damping constants are replaced by N=2 or N=4 degrees radiation damping constants. And we use the new model to recalculate the simulation of DHO model near the band gap. After calculating dielectric function of semiconductors, we compare results with experimental data and other models. We demonstrate that our model can fit in with experimental data in a large region and improve effectively poor fitting of other models near band gap.