In the framework of the effective-mass approximation and the modified Lee-L
ow-Pines variational method, we present a theoretical study of the effect o
f the confined longitudinal-optical phonon and two types of surface-optical
phonon (top and side mode) on the binding energy of shallow donor in cylin
drical quantum dot. The effect of quantum confinement is described by an in
finitely deep potential well. The impact of these different phonon modes is
important and depends on the dimension of the quantum dot.