Hydrostatic pressure and temperature effects on the electronic localized states in \(\textrm{ZnO} / \textrm{Zn}_{1-\textrm{x}} \textrm{Mg}_{\textrm{x}} \textrm{O}\) multi-quantum wells

Abstract

Using the interface response theory formalism, we present a theoretical study on the effect of hydrostatic pressure and temperature on the behavior of localized electronic states and eigenstates of a new MQWs consisting of two semiconductors: \(\textrm{ZnO}\) as a well’s material and \(\textrm{Zn}_{1-\textrm{x}} \textrm{Mg}_{\textrm{x}} \textrm{O}\) as a barrier material. We found that the concentration, the thickness of the defect layer, the pressure, and the temperature have a remarkable effect on the states that appear in the gaps. We observe that the increase in the hydrostatic pressure, and the thickness of the defect layer induce a shift of the states towards the lower energies. On the other hand, the increase in the temperature, and the penetration of the defect layer induce a notable shift towards the higher energies. These results give us the ability to modify and regulate the states that manifest in the inner bands by changing the parameters of the defective layer or the exposure of the system to external perturbations. These electronic states are of practical interest for the characterization of electronic properties of thin film materials and can be the basis for new electronic and optoelectronic devices. Among the most important results in our work, we find that the use of a MQWs of thickness \(\textrm{d}_{1}=\textrm{d}_{2}=40 \mathrm {~A}^{\circ }\) and a percentage of \(25 \%\) of Mg for the barrier material, with the introduction of a geomaterial defect in the 5th well of our system, There is the appearance of a single defect state that has a higher sensitivity than a material or geomaterial defect, such as \(\textrm{S}=0.349\, \textrm{meV} / \textrm{Kbar}\) for pressure variation and \(\textrm{S}=0.8447\,\textrm{meV} / ^{\circ } \textrm{K}\) for temperature variation, which allows the use of this structure as an active layer of a pressure or temperature sensor.