Computational Investigation of Effect of Different Masses of Electron and Hole on Dielectric Moment of Exciton in a Conic Quantum Dot

The excitonic wave-functions and dipole moments in a conic quantum dot with spherical base are numerically calculated. To perform the computations, a computer code, developed by the authors to solve Schrodinger equation based on the perturbation method of “configuration interaction”, is used. The results show that if the effective masses of electron and hole are equal, then exciton dipole moment of all excitonic eigen-states will be equal to zero. On the other hand, the exciton will have dipole moment when the masses of electron and hole are different. When the electron mass is larger than that of hole, the moment orientation is directed towards the cone apex and when the electron mass become smaller the direction is inverted. From this finding it is revealed that difference of electron and hole masses in quantum dots lacking inversion center (here a conic one) causes an intrinsic electrical polarization in the confined exciton.