Efficient intraband optical transitions in Si nanocrystals

G. Allan; C. Delerue

doi:10.1103/physrevb.66.233303

Erratum: “Optical transitions and energy relaxation of hot carriers in Si nanocrystals” [Appl. Phys. Lett. 97, 231116 (2010)]

Applied Physics Letters ◽

10.1063/1.4803012 ◽

2013 ◽

Vol 102 (16) ◽

pp. 169903 ◽

Cited By ~ 2

Author(s):

A. N. Poddubny ◽

A. A. Prokofiev ◽

I. N. Yassievich

Keyword(s):

Energy Relaxation ◽

Optical Transitions ◽

Hot Carriers ◽

Si Nanocrystals

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Evidence of quantum confinement effects on interband optical transitions in Si nanocrystals

Physical Review B ◽

10.1103/physrevb.82.045302 ◽

2010 ◽

Vol 82 (4) ◽

Cited By ~ 52

Author(s):

M. I. Alonso ◽

I. C. Marcus ◽

M. Garriga ◽

A. R. Goñi ◽

J. Jedrzejewski ◽

...

Keyword(s):

Quantum Confinement ◽

Optical Transitions ◽

Confinement Effects ◽

Quantum Confinement Effects ◽

Si Nanocrystals

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Defects and Phonon Assisted Optical Transitions in Si Nanocrystals

MRS Proceedings ◽

10.1557/proc-536-39 ◽

1998 ◽

Vol 536 ◽

Author(s):

G Allan ◽

C Delerue ◽

M Lannoo

Keyword(s):

Radiative Recombination ◽

Surface Defect ◽

Great Sensitivity ◽

Vibration Modes ◽

Optical Transitions ◽

Bulk Silicon ◽

New Approach ◽

Radiative Transitions ◽

Si Nanocrystals ◽

Full Calculation

AbstractPhonon-assisted and zero-phonon radiative transitions in nanoscale silicon quantum dots are studied using a new approach which combines a full calculation of the confined electronic eigenstates and vibration modes. We predict that the confinement, combined with the indirect bandgap of bulk silicon, must have several important consequences on the luminescence of a single silicon dot: i) a large broadening of the peaks, in the range of 10s of meV for a 3 nm dot, in spite of the atomic-like electronic structure of the dot ii) a great sensitivity of the spectrum to the size and the shape of the dot. We obtain that phonon-assisted transitions always dominate, even for size below 2 nm. Finally, we show that the radiative recombination in presence of an oxygen related surface defect (Si=O) is also assisted by optical phonons.

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Electroreflectance Study of Porous Silicon made from Substrates with Different Resistivities

MRS Proceedings ◽

10.1557/proc-638-f3.5.1 ◽

2000 ◽

Vol 638 ◽

Author(s):

Toshihiko Toyama ◽

Yasuharu Nakai ◽

Hiroaki Okamoto

Keyword(s):

Crystal Size ◽

Transition Energy ◽

Optical Transitions ◽

Porous Si ◽

Electron Hole ◽

Si Substrates ◽

Spherical Quantum Dot ◽

Spectral Changes ◽

Mass Approximation ◽

Si Nanocrystals

AbstractEmploying electroreflectance (ER) spectroscopy, we have studied optical transitions in porous Si (PSi) with a thickness of 100±50 nm made from crystalline Si (c-Si) substrates with different resistivities, 4–10 ωcm (p-), 0.1–1 ωcm (p), and < 0.018 ωcm (p+). The ER features observed at 1.1–2.8 eV in p+ PSi are analyzed with a simple effective mass approximation (EMA) model for confined electron-hole (e-h) pairs in a spherical quantum dot as we have previously done for those observed at 1.2–3.1 eV in p- PSi. From the ER analysis with the EMA model, the effective crystal size is estimated without destruction, and the kinetic energy and the Coulomb attraction energy of the confined e-h pairs are also deduced.Furthermore, the ER features corresponding to the optical transitions at E1(E0') critical point (CP) are observed at 2.8–3.3 eV in p+ PSi. With an increase in the crystal size, the transition energy of E1(E0') CP in p+ PSi is decreased, while that in p- and p PSi is unchanged from that of 3.4 eV found in c-Si including the p+c-Si. From the Raman results, strain- and disorder-induced spectral changes are found to be negligible, so that the high doping induced effect is the most acceptable mechanism for the red-shift in E1(E0') transitions of Si nanocrystals with the crystal size of 2–3 nm.

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