Effect of dielectric mismatch on impurity binding energy in double ellipsoidal quantum dots

• Binding energy of hydrogenic impurity in double ellipsoidal quantum dot (DEQD) is calculated.
• Effect of dielectric mismatch due to different regions on the binding energy in DEQD is investigated.
• Effect of self polarization energy due to the interaction of charge with its induced charge is considered.
• Surface polarization charges reduce the energy of carriers.
• Self polarization energy increases the electron energy.

The present study seeks to scrutinize the effect of polarization charges on the electronic properties of double ellipsoidal quantum dots. In this regard, the effective-mass approximation within a variational scheme is used and the binding energy of hydrogenic impurity located at the center of ellipsoidal quantum dot (EQD) is calculated for GaAs/GaAlAs/AlAs structure. The effect of surface polarization charges due to impurity and self-polarization charges on the binding energy is considered. The results showed that the binding energy depends not only on the thickness of the intermediate layer but also on the ellipticity constant.

The variation of binding energy versus semi-axis of the ellipsoidal quantum dot for different dielectric constants of well and barrier regions. Figure optionsDownload as PowerPoint slide