重碳掺杂p型GaAs中纵光学声子与等离振子耦合模的Raman散射特性

RAMAN SCATTERING STUDY OF LO PHONON-PLASMON COUPLED MODE IN HEAVILY CARBON DOPED p-TYPE GaAs

对用MOMBE法生长的重C掺杂p型GaAs进行了Raman散射研究,结合理论分析,较好地解释了p型GaAs中纵光学(LO)声子与空穴等离振子耦合(LOPC)模的Raman散射特性,证明它具有与n型状态不同的特点,根据实验结果讨论了重掺杂对Raman散射谱的影响,发现LOPC模的散射峰特征(位置和宽度)与重掺杂效应程度具有很大关系。

The Raman scattering by LO phonon-plasmon coupled (LOPC) mode in heavily carbon doped p-type GaAs grown by MOMBE has been studied. It was shown by the lineshape analysis based on a theoretical model for the Raman scattering rate that the p-type GaAs has only one LOPC structure in contrast to the two modes in n-type doping case. The influence of heavily doping on the Raman spectroscopy was also discussed based on the experimental results. The linewidth broadening and the red shift of the LOPC mode scattering peak at the ul-trahigh doping level are induced by the crystalline disorder and effects of lattice deformation.