The results of theoretical calculations of electronic states of the gallium oxide (Ga2O3) nanocrystals both doped with donor impurity and undoped have been presented in the paper. In the envelope function approximation, the structure, states and energy levels of size quantization in the nanocrystals were determined. According to our calculations, the electron-hole pair forms a bound state of the exciton type in the nanocrystal. The typical donor impurities in Ga2O3, such as silicon and tin, were shown to create bandgap states localized in a spatial domain being several times smaller than the nanocrystal’s volume. Forming a compact neutral pair, the electron and donor ions have no noticeable influence on the states of the optically excited electron-hole pairs. The effect of impurity implantation on recombination processes was also discussed.

This work is devoted to the theoretical calculation of the electronic states of dimensional quantization of the systems Al2O3: nc-Ga2O3. and SiO2: nc-Ga2O3. The electron levels of the conduction band and the holes of the valence band are calculated. The levels of small donors and acceptors were calculated. The reasons for the shift of the photoluminescence peak are discussed

The wave functions of electrons localized at P, As, and Sb shallow donors in Ge are calculated in the envelope function approximation taking into account valley–orbit coupling induced by the short-range donor potential. An approach is proposed that makes it possible to include intervalley mixing into the equation for the multicomponent envelope function. The effects of valley–orbit coupling are calculated using perturbation theory and the single-valley “bare” functions are determined by the Ritz method. The parameters of the short-range part of the potential and the coefficient of intervalley mixing are found for each donor individually and yield the best agreement with the measured energies of the singlet and triplet states. The envelope functions of the 1s(A1) and 1s(T2) states are calculated. The parameters of the valley–orbit interaction for each donor are obtained. It is shown how the functions of the 2s, 2p0, 2p±, and 3p0 excited states should be modified to remain orthogonal to the singlet and triplet functions in the framework of a more rigorous multivalley model.

In the framework of the envelope function approximation, the wave functions of electrons localized at shallow donors P, As, Sb in Ge are calculated taking into account the valley-orbit coupling caused by the donor short-range potential. It is proposed an approach that makes it possible to include inter-valley mixing in the equation for a multi-component envelope function. The calculation of the effects of the valley-orbit interaction was carried out according to the perturbation theory, while the "bare" single-valley functions were found using the Ritz method. The parameters of the short-range part of the potential and the coefficient of inter-valley mixing were found individually for each donor, making it possible to obtain the best agreement with the results of experimental measurements of the energies of the singlet and triplet states. The envelope functions of the 1s(A1) and 1s(T2) states are calculated. The parameters of the valley-orbit interaction are found for each donor. It is also shown how the functions of the excited 2s, 2p0, 2p±, 3p0 states should be modified in order to remain orthogonal to the singlet and triplet functions within the framework of a more rigorous multivalley model.

In the framework of the envelope function approximation, the wave functions of low-lying 1s(A1), 2s, 2p0, 2p±, 3p0 states of shallow donor centers P, As, Sb in germanium are calculated considering the short-range part of the impurity potential. The latter is constructed individually for each impurity, taking into account the spatial dispersion of the dielectric function and the difference between the ionic cores of germanium and the impurity center. The envelope function equation was solved using the Ritz variational method, and selected trial wave functions of the orbitally non-degenerate s-states are characterized by two spatial scales: the first one is of the order of the donor effective Bohr radius and corresponds to the long-range part of the potential, and the second one, which is an order of magnitude less, simulates the electron response to the short-range part of the donor potential. The electron density in the donor ground state is shifted to the nucleus due to the attractive “central cell” correction. The envelope functions of p-states, in turn, are constructed in such a way they are orthogonal to the ground state envelope functions for each impurity center, and, unlike previous works, are different for various donors.