Photoluminescence quantum and surface states of excitons in ZnSe and CdS nanoclusters

New quasi-atomic nanostructures containing exciton quasimolecules and exciton quasicrystals: theory

“…In order to explain the optical characteristics of such nanosystems we proposed a model of a quasimolecule representing two ZnSe and CdS QDs that form an exciton quasimolecule as a result of the interaction of electrons and holes. t was noted [25,27] that, at such a QD content in the samples, one must take into account the interaction between charge carriers localized above the QD surfaces. Therefore, in [10,15], we develop the theory of a exciton quasimolecule (or biexciton) (formed from spatially separated electrons and holes) in a nanosystem that consists of ZnSe and CdS QDs synthesized in a borosilicate glassy matrix.…”

“…We show that the biexciton formation is of the threshold character and possible in a nanosystem, in which the spacing between the QD surfaces exceeds a certain critical spacing. It is established that the spectral shift of the low-temperature luminescence peak [27] in such a nanosystem is due to quantum confinement of the energy of the biexciton ground state.…”

Excitonic Quasimolecules in Nano Systems of Semiconductor and Dielectric Quantum Dots

“…The certain orbitals, localized surrounding quantum dot correspond to electrons in superatom [2,3]. During investigation of the optical characteristics of nanosystems with CdS, ZnSe, Al 2 O 3 and Ge quantum dots in experimental papers [4][5][6][7][8] it was found that the electron can be localized above the surface of the QD while the hole here moves in the volume of the QD. In Ref.…”

“…In Ref. [4][5][6][7][8] the appearance of super atoms located in dielectric matrices as cores containing CdS, ZnSe, Al 2 O 3 and Ge quantum dots was apparently established experimentally for the first time. A substantial increase in the bond energy of the ground state of an electron in a super atom in comparison with the bond energy of an exciton in CdS, ZnSe and Al 2 O 3 and single crystals was detected in Ref.…”

“…A substantial increase in the bond energy of the ground state of an electron in a super atom in comparison with the bond energy of an exciton in CdS, ZnSe and Al 2 O 3 and single crystals was detected in Ref. [2][3][4][5][6][7][8][9][10].…”