Charge States of Single Quantum Dots in a Microcavity p–n–p Heterostructure with the Built-in Coulomb Blockade

The charge state of single InAs/GaAs quantum dots in microcavity p–n–p heterostructures in the presence of built-in Coulomb blockade induced by a thin layer with the n-type conductivity located near quantum dots is studied. The optimal doping profile and thickness of layers in the heterostructure are determined analytically by solving the Poisson equation. The number and sign of carriers in a single quantum dot are determined by experimental studies of spin dynamics and statistics of single-photon radiation under resonant and quasi-resonant excitation. The possibility of obtaining neutral and positively and negatively charged quantum dots with a probability exceeding 90% is shown, which opens up new opportunities for the study of optical processes in single quantum dots and their application in quantum photonics.