Intensity of Radiative Recombination in the Germanium/Silicon Nanosystem with Germanium Quantum Dots

Sergey I Pokutnyi,Lucjan Jacak

doi:10.3390/cryst11030275

Abstract

It is shown that in a germanium/silicon nanosystem with germanium quantum dots, the hole leaving the germanium quantum dot causes the appearance of the hole energy level in the bandgap energy in a silicon matrix. The dependences of the energies of the ground state of a hole and an electron are obtained as well as spatially indirect excitons on the radius of the germanium quantum dot and on the depth of the potential well for holes in the germanium quantum dot. It is found that as a result of a direct electron transition in real space between the electron level that is located in the conduction band of the silicon matrix and the hole level located in the bandgap of the silicon matrix, the radiative recombination intensity in the germanium/silicon nanosystem with germanium quantum dots increases significantly.

Highlights

National Laboratory for Quantum Technologies, Wrocław University of Science and Technology, Abstract: It is shown that in a germanium/silicon nanosystem with germanium quantum dots, the hole leaving the germanium quantum dot causes the appearance of the hole energy level in the bandgap energy in a silicon matrix
To fill a gap in the theory, in this work, we develop the theory of spatially indirect excitons (SIE) in a nanosystem taking into account the possibility of a hole leaving the valence band of germanium quantum dots (QDs) into the bandgap of the silicon matrix
Of electron transition and radiation intensity ( I1,0 (a)/C ) (24), as a function of the mean radius a of the germanium QD, for a nanosystem containing germanium QDs grown in a silicon matrix, with mean QD radii a in the interval (12)

Summary

Introduction

National Laboratory for Quantum Technologies, Wrocław University of Science and Technology, Abstract: It is shown that in a germanium/silicon nanosystem with germanium quantum dots, the hole leaving the germanium quantum dot causes the appearance of the hole energy level in the bandgap energy in a silicon matrix. The spatial separation of electrons and holes, as a result of which electrons were localized above the QD and holes moved into QD, was found in the germanium/silicon heterostructure [9,10,11,12,13,14,15,16,17,18,19,20,21] Such excited states have been called spatially indirect excitons (SIE) [9,10,11,12,13,14,15,16,17,18,19,20,21,22].

Results

Discussion

Conclusion