Size and shape effects on effective mass, electronic and optical properties of V-shaped quantum dot: influence of an off-center donor atom, hydrostatic pressure and temperature

In the present study, we discuss theoretically the role of hydrostatic pressure and temperature on the electron and light-hole states with a shallow-donor impurity confined in a V-shaped quantum dot. The global shape of the system depends essentially on the aperture angle, which allows to pass from a 2D-rectangular surface to a cylindrical shaped structure. In the case of infinite potential barrier, the eigenvalues and eigenenergies from the Schrödinger equation are calculated using the finite difference method within the framework of the effective mass approximation. The obtained results show that the donor binding energy varies with the hydrostatic pressure, temperature, geometrical parameters (aperture angle, height, and radius), and the impurity position. We have also noted that the donor binding energy increases with the hydrostatic pressure and its variation is more important for small values of aperture angle and radius (small quantum dots) and decreases slightly with the temperature. Thus, we can control the properties of donor impurity not only with the internal parameters but also with an adapted choice of externals effects like hydrostatic pressure and temperature in order to help the developers to create new optoelectronic devices. In this study, the effect of non-parabolicity in the conduction effective mass has been considered, demonstrating the importance of considering the effective mass-size relationship for structures whose dimensions are in the order of magnitude of the effective Bohr radius.