Electron-phonon interaction in semiconductor spherical quantum dot embedded in a semiconductor medium (HgS/CdS)

Different types of electron (hole) ground energy level renormalization due to confined (L) and interface (I) phonons in a spherical quantum dot embedded in a semiconductor medium are investigated on the example of beta -HgS/CdS nanoheterosystem. It is shown that for all QD sizes the shift of the ground energy level (Delta) is generally caused by the interaction of electron and confined phonons of the dot (L-0) and of the medium (L-1). The contribution of interface phonons (I+ I-) to the magnitude Delta is comparable with the contribution of L-phonons only at small QD radii tit is three times smaller). For all QD radii the interaction with all phonons through all stales of the continuous spectrum gives a one order smaller contribution to Delta than the interaction through the states of the discrete spectrum. When the QD radius increases the I-phonon contribution decreases and the L-phonon one increases, consequently, the total shift becomes closer to its magnitude in hulk HgS crystal.