Effect of pressure on donor states in a spherical GaAs — Ga_1−x Al_x, As quantum dot

Abstract

We have calculated the binding energies as a function of pressure up to 4 Gpa for on-centre shallow donor impurities in a spherical GaAs-Ga1-_x, Al_x, As quantum dot for both finite and infinite barriers following a variational procedure within the effective mass approximation including the spatial variation of dielectric screening. Results reveal that the characteristics of variation of donor binding energy with dot radius at a given pressure is the same as those at zero pressure, and the binding energies increase with the increase of pressure. The increase becomes more and more as the dot radius decreases. The effect of pressure are similar to the effects due to the variation of A1 concentration x.

Key Words:

• High pressure
• donor states
• low dimensional system
• quantum dot
• semiconductor heterostructures