Temperature dependence of the 11H photoreflectance lineshape in an (001) In0.21Ga0.79As/GaAs single quantum well

摘要

Abstract: The photoreflectance lineshape of the 11H exciton peak in an In$- 0.21$/Ga$-0.79$/As/GaAs single quantum well was measured from 10 K to 500 K. In contrast to the GaAs/GaAlAs system our 10 K data exhibited no `wings' and can be fit equally well by the first- derivative of a Gaussian or Lorentzian profile. The former is probably relevant since the well material is an alloy. These results indicate that care must be taken in associating spectra without pronounced `wings' with the Lorentzian profile. The temperature dependence of the 11H linewidth, which has been fit to a Bose-Einstein expression, yields important information about the quality of the material and interface. The variation of the energy of 11H with temperature agrees with that of bulk material. !24