Magnetic field effect on recombination radiation, bound with $A^+$-centers in quantum dots

Background. An interest to optical properties of quantum dots with $A^+$-centers in a magnetic field is aroused, first of all, by a possibility of efficient control of both the $A^+ + e$ extrinsic complexes binding energy and spectral curves of recombination radiation, bound with luminous electron's radiative transition to the $A^+$-center level. Depending on the quantum dot radius the recombination radiation spectrum may be located both in visible and terahertz bandwidth, significantly increasing a range of instrument applications of the system under consideration. The study is aimed at theoretical research of external magnetic field effect on the energy binding a hole in the $A^+ + e$ extrinsic complex with a spherically symmetric dot, as well as on frequency dependence of spectral intensity of recombination radiation of a quasi-zero-dimensional structure with $A^+ + e$ extrinsic complexes. Materials and methods. Dependence of the $A^+$-condition's binding energy on extrinsic center's coordinates in a magnetic field, as well as frequency dependence of spectral intensity of recombination radiation in a quasi-zero-dimension structure with $A^+ + e$ extrinsic complexes were built for InSb quantum dots. Hole's binding energy in the $A^+ + e$ extrinsic complex was calculated in the model of zero radius potential in adiabatic approximation. Spectral intensity of recombination radiation was calculated dipole approximation taking into account quantum dots' radius dispersion. Results. It is shown that modification of electron conditions in a quantum dot, stipulated by hybrid quantization in a radial plane and dimensional quantization towards a magnetic field, is the cause of dimensional anisotropy of hole's binding energy in the $A^+ + e$ extrinsic complex. It has been found that spectral intensity of recombination radiation in a magnetic field rises, caused by an increase of an overlap integral of envelope wave functions of a hole, bound on the $A^+$-center, and of an electron, localized in the quantum dot's ground state. Conclusions. In a magnetic field there occurs dimensional anisotrophy of hole's binding energy in the $A^+ + e$ complex, shifting of the curve of spectral intensity of recombination radiation into the short-wave region of the spectrum and an increase of a probability of electron's radiative transition to the $A^+$-center level.