用介电函数的三级微商谱精确确定Ga_xIn_(1-x)P临界点的能量值

Accurately Determining the Position of Interband Transition Energy for the Ga xIn 1-x P by the Third Derivative Spectra of Dielectric Functions

本文导出了弱电场调制反射谱与介电函数对能量的三级微商成正比。将ＭＯＣＶＤ方法生长的ＧａＩｎＰ以及掺Ｓｉ和掺Ｚｎ３个样品，用椭圆偏振光谱法测量得到可见光区的介电函数谱，并求其三级微商谱。把用来分析电反射谱的三点法推广到分析介电函数的三级微商谱，得到弱电场调制反射谱的实验结果，并与介电函数谱的结果加以比较。

In this paper,it was derived that the modulated reflective spectrum of weak electric field is proportional to the third derivative of the dielectric functions with respect to the energy.The dielectric function spectra for GaInP and doped Si or Zn GaInP samples grown by MOCVD were obtained in the region of visible light by using the ellipsometric spectroscopy,and then the third derivative spectra were evaluated.Extending the three point scaling used in the analysis of the electric reflective spectrum,the third derivative spectra of the dielectric functions can be analyzed.The experimental results of reflective spectra of weak electric field modulation were obtained and compared with that of the dielectric function spectra,the sensitivity and resolution ratio increase remarkably.