The polaron free energy in a GaAs/Al/As quantum well is calculated as a fun
ction of temperature and well width. The interaction considered is that bet
ween the conduction electrons and the GaAs-like polar optical oscillations.
The calculation follows a perturbative scheme in the coupling constant for
the thermodynamical potential in the one-particle limit. Phonons are descr
ibed with the use of a long-wavelength dispersive electroelastic continuum
model.