Hydrostatic pressure effect on photoionization cross section of a trion in quantum dots

• The photoionization of trions in a quantum dot is investigated.
• By varying hydrostatic pressure, one can control the photoionization of trions.
• Photoionization cross section of a X− is much larger than that of a X+ in the same case.

It is known experimentally that stable charged excitons can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body problems are very difficult to solve, even numerically. Here, we use the matrix diagonalization method and compact-density approach to investigate the charged excitons in a two-dimensional parabolic quantum dot. With typical semiconducting GaAs based materials, the photoionization cross section has been examined based on the computed energies and wave functions. We find that the photoionization cross section of charged excitons is strongly affected by the confinement frequency, hydrostatic pressure and temperature of QDs. Our results also show that the photoionization cross section of a negatively charged exciton is larger than that of a positively charged exciton.