The electro-reflectance lineshape for a quantum well: the dependence on angle of incidence and temperature

The authors have studied the effect of varying both the angle of incidence and the temperature on electro-reflectance spectroscopy (ERS) measurements for a 100AA p-i-n single quantum well structure of GaAs/Ga0.8Al0.2As in which the electric field is applied perpendicularly to the well. The effect of each variation is to change the effective optical path between the semiconductor-air interface and the quantum well. In each case, they observe changes in the lineshape that are consistent with the simple rules reported previously for interpreting ERS measurements on single quantum well structures. They here rederive the rules analytically using the 'etalon' model for the semiconductor structure and demonstrate both experimentally and theoretically the inversion of the ERS lineshape when the optical path changes by a quarter wavelength.