Energy level broadening control in quantum dots by interfacial doping

A method is proposed to diminish the energy level broadening in quantum dots due to size fluctuations. It is shown that doping the graded interface region of quantum dots can considerably reduce the broadening of their energy levels. In the case of spherical GaAs/Al0.3Ga0.7As dots of radii ∼50 Å and interface width 20 Å, the presence of a Si donor in the middle of the interfaces can decrease their energy level broadening by as much as 20 meV.