Excitons in cylindrical GaAs Pöschl-Teller quantum dots: Hydrostatic pressure and temperature effects

The exciton binding energy in a cylindrical quantum dot with Pöschl-Teller (PT) confining potential is studied with the use of the effective mass approximation and a variational calculation procedure. A GaAs prototype structure is particularly considered and different geometric configurations are taken into account by modifying the pair of parameters associated with the PT potential. We show that there is a significant effect of the PT quantum well symmetry profile on the exciton properties. Pressure and temperature effects can be summarized as follows: exciton binding energy is a decreasing function of temperature for fixed pressure, and an increasing function of pressure for fixed temperature. We also report the variation of the photoluminescence peak position as a function of QD dimensions for different PT confining regimes. In addition, the pressure coefficient of the photoluminescence peak transition energy is theoretically evaluated. It is shown that this quantity may exhibit negative values in quantum dots of reduced size.