Hot-carrier radiative recombination through phonon confinement in silicon nanocrystals embedded in colloidal xerogel matrix

2021 ◽  
Vol 130 (3) ◽  
pp. 033102
Author(s):  
Susmita Biswas ◽  
Anupam Nandi ◽  
Ujjwal Ghanta ◽  
Biswajit Jana ◽  
Sumita Mukhopadhyay ◽  
...  
Keyword(s):  
Silicon Nanocrystals ◽  
Radiative Recombination ◽  
Phonon Confinement ◽  
Hot Carrier

Impact of Anchoring Monolayers on the Enhancement of Radiative Recombination in Light-Emitting Diodes Based on Silicon Nanocrystals

2018 ◽  
Vol 122 (11) ◽  
pp. 6422-6430 ◽  
Author(s):  
Batu Ghosh ◽  
Takumi Hamaoka ◽  
Yoshihiro Nemoto ◽  
Masaki Takeguchi ◽  
Naoto Shirahata
Keyword(s):  
Silicon Nanocrystals ◽  
Radiative Recombination ◽  
Light Emitting Diodes ◽  
Light Emitting

scholarly journals Depth-Resolved Microspectroscopy of Porous Silicon Multilayers

1999 ◽  
Vol 588 ◽  
Author(s):  
S. Manotas ◽  
F. Agulló-Rueda ◽  
J. D. Moreno ◽  
R. J. Martín-Palma ◽  
R. Guerrero-Lemus ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Quantum Confinement ◽  
Silicon Nanocrystals ◽  
Phonon Frequency ◽  
Lattice Mismatch ◽  
High Porosity ◽  
Phonon Confinement ◽  
Heating Effects ◽  
Average Size ◽  
Good Agreement

AbstractWe have measured micro-photoluminescence (PL) and micro-Raman spectra on the cross section of porous silicon multilayers to sample different layer depths. We find noticeable differences in the spectra of layers with different porosity, as expected from the quantum confinement of electrons and phonons in silicon nanocrystals with different average sizes. The PL emission band gets stronger, blue shifts, and narrows at the high porosity layers. The average size can be estimated from the shift. The Raman phonon band at 520 cm−1 weakens and broadens asymmetrically towards the low energy side. The line shape can be related quantitatively with the average size by the phonon confinement model. To get a good agreement with the model we add a band at around 480 cm−1, which has been attributed to amorphous silicon. We also have to leave as free parameters the bulk silicon phonon frequency and its line width, which depend on temperature and stress. We reduced laser power to eliminate heating effects. Then we use the change of frequency with depth to monitor the stress. At the interface with the substrate we find a compressive stress in excess of 10 kbar, which agrees with the reported lattice mismatch. Finally, average sizes are larger than those estimated from PL.

Improved one-phonon confinement model for an accurate size determination of silicon nanocrystals

1999 ◽  
Vol 86 (4) ◽  
pp. 1921-1924 ◽  
Author(s):  
V. Paillard ◽  
P. Puech ◽  
M. A. Laguna ◽  
R. Carles ◽  
B. Kohn ◽  
...  
Keyword(s):  
Silicon Nanocrystals ◽  
Size Determination ◽  
Phonon Confinement ◽  
Confinement Model

scholarly journals Direct modulation of electroluminescence from silicon nanocrystals beyond radiative recombination rates

2008 ◽  
Vol 92 (9) ◽  
pp. 091103 ◽  
Author(s):  
Josep Carreras ◽  
J. Arbiol ◽  
B. Garrido ◽  
C. Bonafos ◽  
J. Montserrat
Keyword(s):  
Silicon Nanocrystals ◽  
Radiative Recombination ◽  
Recombination Rates ◽  
Direct Modulation

scholarly journals Probing the phonon confinement in ultrasmall silicon nanocrystals reveals a size-dependent surface energy

2011 ◽  
Vol 109 (8) ◽  
pp. 083534 ◽  
Author(s):  
Iain F. Crowe ◽  
Matthew P. Halsall ◽  
Oksana Hulko ◽  
Andrew P. Knights ◽  
Russell M. Gwilliam ◽  
...  
Keyword(s):  
Surface Energy ◽  
Silicon Nanocrystals ◽  
Phonon Confinement ◽  
Size Dependent

Embedded Silicon Nanocrystals Studied by Photoluminescence and Raman Spectroscopies: Exciton and Phonon Confinement Effects

2010 ◽  
Vol 114 (41) ◽  
pp. 17344-17349 ◽  
Author(s):  
Patrice Miska ◽  
Manuel Dossot ◽  
Thi D. Nguyen ◽  
Matthias Grün ◽  
Hervé Rinnert ◽  
...  
Keyword(s):  
Silicon Nanocrystals ◽  
Phonon Confinement ◽  
Confinement Effects

Thermoelectric Nanowire Junction Photoresponse

2014 ◽  
Vol 1642 ◽  
Author(s):  
Tito E. Huber ◽  
Scott D. Johnson ◽  
Tina Brower ◽  
Quinton Barclift ◽  
Benjamin Panga ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Light Trapping ◽  
Nanowire Arrays ◽  
Heat Diffusion ◽  
Quasi Equilibrium ◽  
Phonon Confinement ◽  
Thermoelectric Effects ◽  
Indium Tin Oxide Electrode ◽  
Hot Carrier ◽  
Optical Wavelength

ABSTRACTRecently there have been reports of hot carrier thermoelectric response in nanostructured materials like graphene and MoS. We report observing that thermoelectric nanowire junctions detect light. In these experiments we employed devices composed of bismuth nanowire arrays which are capped with a transparent indium tin oxide electrode. The incident surface features very low optical reflectivity and enhanced light trapping. The unique attributes of the thermoelectric arrays are the combination of strong temporal and optical wavelength dependences of the photocurrent. Under infrared illumination, the signal can be completely described by “quasi-equilibrium” thermoelectric effects considering cooling rates given by heat diffusion through the array. The thermal diffusivity is found to be less (by a factor of 3.5) than in the bulk, a result that we discuss in terms of phonon confinement effects. In addition to a thermoelectric response, under visible illumination, we observe a photovoltaic response.

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