The density of electronic states in silicon nanocrystals in a SiO2 matrix and with a hydrogen passivated surface

Gert A.V., Belolipetskii A.V., Avdeev I.D.

For Russian citation (Opticheskii Zhurnal):

Герт А.В., Белолипецкий А.В., Авдеев И.Д. Плотность электронных состояний в нанокристаллах кремния в матрице SiO₂ и с пассивированной водородом поверхностью // Оптический журнал. 2024. Т. 91. № 6. С. 39–46. http://doi.org/ 10.17586/1023-5086-2024-91-06-39-46

Gert A.V., Belolipetsky A.V., Avdeev I.D The density of electronic states in silicon nanocrystals in a SiO₂ matrix and with a hydrogen passivated surface // Opticheskii Zhurnal. 2024. V. 91. № 6. P. 39–46. http://doi.org/ 10.17586/1023-5086-2024-91-06-39-46

For citation (Journal of Optical Technology):

Abstract:

Subject of study. The work dedicates to optical transitions and absorption cross-section calculation in the silicon nanocrystals in a SiO₂ dielectric matrix and nanocrystals passivated with hydrogen. Purpose of study. Calculate the probability of optical transitions and the density of electronic states in silicon nanocrystals with different environments, adapt the tight-binding method for correct passivation of dangling silicon bonds. Method. The work uses a variant of the tight binding method taking into account a large number of s, p, d and s* orbitals. Main results. The local density of states of electrons and holes, the probabilities of optical transitions, and the absorption cross section in silicon nanocrystals passivated with hydrogen and nanocrystals placed in a SiO₂ matrix are calculated. It has been shown that electronic and hole states in passivated silicon nanocrystals are localized inside the crystal; optical transitions occur with a wavelength in the range of 440–620 nm. Surrounding the SiO₂ matrix leads to an increase of the probability of optical transitions and the appearance of density of states outside the nanocrystal; radiation in this case occurs in the wavelength range 410–620 nm. Practical significance. Prospects for the use of silicon nanocrystals in photonics and photovoltaics, development of technology for creating silicon nanocrystals with specified optical properties.

Keywords:

silicon nanocrystals, tight-binding method, surface passivation

Acknowledgements:

the authors express gratitude to M.O. Nestoklon for his contribution to the development of the method used in the work. I.D. Avdeev expresses gratitude to the Foundation for the Developmentof Theoretical Physics and Mathematics "BASIS" for the support provided.

OCIS codes: 250.5590 160.4236

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