摘要
分析了波长调制反射谱,实际是介电函数对能量的一级微商。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Zn三个样品,用椭偏光谱法测量得到可见光区的介电函数谱,并求其一级和三级微商谱。将用于分析电反射谱的三点法推广用于分析介电函数的一级和三级微商谱,得到波长调制和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,使灵敏度和分辨率有很大提高。
we point out that the wavelength modulated reflective spectrum essentially is the first derivative of dielectric functions with respect to the energy . 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 GalnP 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 first and third derivative spectra were evaluated. Extending the three - point - scaling used in the analysis of the electric reflective spectrum, the first and third derivative spectra of the dielectric functions can be analyzed . The experimental results of reflective spectra of wavelength modulation and weak electric field modulation were obtained and compared with that of dielectric function spectra. The sensitivity and resolution ratio increase remarlkably.