Charge distribution in quantum dot with trapped exciton

We calculate the ground state wave function of the exciton confined in the In0.55Al0.45As quantum disk, lens and pyramid deposited on a wetting layer (WL) and embedded in a matrix made of Al0.35Ga0.65As material. It is shown that tunneling of the electron into the barrier is significantly stronger than one of the holes due to the difference between their masses. In consequence, the central region of the dot with captured exciton is charged positively whereas the regions over, below and around quantum dot including the WL are charged negatively. The comparison of results obtained for quantum dots (QDs) with different geometry shows that the separation of the charges is stronger in spike-shaped quantum dots. We also find that the increase of the WL thickness leads to a lowering of the effective barrier height for both particles enhancing the separation between them in the lateral direction provided by reinforced the particles tunneling toward the WL.