

Optical properties of nearsurface exciton quantum wells*
Felipe PérezRodríguez
Instituto de Física de la Universidad Autónoma de Puebla,
Apdo. Post. J48, Puebla, Pue. 72570, México
An overview of investigations on nearsurface semiconductor quantum
wells, whose optical properties are considerably affected by the
interaction of the exciton with the sample surface will be given. Nearsurface
quantum wells with both weak and strong quantum confinement of excitons
will be considered. In the regime of weak confinement, the effective width
d of the quantum well is much larger than the exciton radius a0 and,
therefore, the centerofmass motion of the exciton is quantized. In the
opposite case (strong confinement regime) the quantumwell thickness d
is smaller than a0, hence the electron and hole are quantized separately
in the growth direction and form a quasi2D exciton due to the inplane
Coulomb interaction. When the exciton quantum well is very close to the
sample surface, exciton dynamics is determined not only by characteristics
of the quantum well, but also by factors such as the noescape condition
for the electron and hole at the sample boundary, the image potential,
and surface roughness. Optical spectra (reflectivity, absorption, and
lightscattering cross section) for various systems of nearsurface quantum
wells will be presented. In addition, recent results for magnetoexcitons
in nearsurface quantum wells will be discussed too.
*: This work is partially supported by CONACYT.








