Quantum confinement effects on optical transitions in nanodiamonds containing nitrogen vacancies

Article

关键词: SMALL SEMICONDUCTOR CRYSTALLITES;    THEORETICAL CHARACTERIZATION;    LARGE MOLECULES;    DIAMOND;    DENSITY;    DOTS;    EXCHANGE;    SILICON;    BAND;    ELECTRON;   

DOI  :  10.1103/PhysRevB.94.165402

来源: SCIE

【 摘 要 】

Colored nitrogen-vacancy (NV) centers in nanosize diamonds (d similar to 5 nm) are promising probe materials because their optical transitions are sensitive to mechanical, vibrational, and spin changes in the surroundings. Here, a linear response time-dependent density functional theory approach is used to describe the optical transitions in several NV-doped diamond quantum dots (QDs) in order to investigate size effects on the absorption spectra. By computing the full optical spectrum up to band-to-band transitions, we analyze both the localized pinned midgap and the charge-transfer excitations for an isolated reduced NV center. Subband charge-transfer excitations are shown to be size dependent, involving the excitation of the dopant sp(3) electrons to the diamond conduction band. Additionally, the NV-doped systems exhibit characteristic sp(3)-sp(3) excitations whose experimental energies are reproduced well and do not depend on QD size. However, the NV position and global cluster symmetry can affect the amount of the energy splitting of the vertical excitation energies of the midgap transitions.

【 授权许可】

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