【摘要】 报道了用光反射调制谱(PR)测量掺杂分子束外延GaAs薄膜表面和界面电场的结果。分别用He-Ne激光和He-Cd激光作调制光,由于它们的穿透深度不同,可以有效地区分来自表面和界面的PR信号。由PR谱推算出薄膜表面和界面的电场。研究了薄膜干涉效应对调制光谱的影响,对界面电场的成因进行了分析和讨论。更多还原

【Abstract】 This paper reports the photoreflectance(PR) measurements of electric fields at the surface and the GaAs-GaAs interface of doped MBE GaAs films. By using alternatively He-Ne laser and He-Cd laser as pumping light, PR signals from the surface and the interface of the film can be effectively seperated the different penetration depth of different light. Electric fields at the surface and the interface were deduced from PR spectra. Film interference effects on modulation spectroscopy are studied. The origin of the electric field generated at interfaces are also discussed.更多还原