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

scholarly journals Dopants Modulate Crystal Growth in Molten Salts Enabled by Surface Energy Tuning

2021 ◽  
Author(s):  
Xiaoqiao Li ◽  
Linming Zhou ◽  
Han Wang ◽  
Dechao Meng ◽  
Guannan Qian ◽  
...  
Keyword(s):  
Crystal Growth ◽  
High Temperature ◽  
Surface Energy ◽  
Molten Salts ◽  
Rational Approach ◽  
Temperature Synthesis ◽  
Crystalline Materials ◽  
Size Dependent ◽  
High Temperature Synthesis ◽  
Energy Tuning

Crystalline materials are routinely produced via high-temperature synthesis and show size-dependent properties; however, a rational approach to regulating their crystal growth has not been established. Here we show that dopants...

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.

scholarly journals Molecular dynamic investigation of size-dependent surface energy of icosahedral copper nanoparticles at different temperature

2016 ◽  
Vol 6 (4) ◽  
pp. 266-270 ◽  
Author(s):  
V. S. Myasnichenko ◽  
M. Razavi ◽  
M. Outokesh ◽  
N. Yu. Sdobnyakov ◽  
M. D. Starostenkov
Keyword(s):  
Surface Energy ◽  
Molecular Dynamic ◽  
Copper Nanoparticles ◽  
Size Dependent ◽  
Dynamic Investigation

Size dependent stability and surface energy of amorphous FePt nanoalloy

2019 ◽  
Vol 788 ◽  
pp. 787-798
Author(s):  
M. Vedat Akdeniz ◽  
Amdulla O. Mekhrabov
Keyword(s):  
Surface Energy ◽  
Size Dependent

Size-Dependent Elasticity of Nanoporous Materials Predicted by Surface Energy Density-Based Theory

2017 ◽  
Vol 84 (6) ◽  
Author(s):  
Yin Yao ◽  
Yazheng Yang ◽  
Shaohua Chen
Keyword(s):  
Energy Density ◽  
Surface Energy ◽  
Volume Fraction ◽  
Surface Effect ◽  
Compressive Strain ◽  
Nanoporous Materials ◽  
Surface Relaxation ◽  
Surface Energy Density ◽  
Closed Form Solutions ◽  
Size Dependent

The size effect of nanoporous materials is generally believed to be caused by the large ratio of surface area to volume, so that it is also called surface effect. Based on a recently developed elastic theory, in which the surface effect of nanomaterials is characterized by the surface energy density, combined with two micromechanical models of composite materials, the surface effect of nanoporous materials is investigated. Closed-form solutions of both the effective bulk modulus and the effective shear one of nanoporous materials are achieved, which are related to the surface energy density of corresponding bulk materials and the surface relaxation parameter of nanomaterials, rather than the surface elastic constants in previous theories. An important finding is that the enhancement of mechanical properties of nanoporous materials mainly results from the compressive strain induced by nanovoid's surface relaxation. With a fixed volume fraction of nanovoids, the smaller the void size, the harder the nanoporous material will be. The results in this paper should give some insights for the design of nanodevices with advanced porous materials or structures.

scholarly journals Size-dependent oxygen-related electronic states in silicon nanocrystals

2004 ◽  
Vol 84 (26) ◽  
pp. 5389-5391 ◽  
Author(s):  
J. S. Biteen ◽  
N. S. Lewis ◽  
H. A. Atwater ◽  
A. Polman
Keyword(s):  
Silicon Nanocrystals ◽  
Electronic States ◽  
Size Dependent

Synthesis of Ligand-Stabilized Silicon Nanocrystals with Size-Dependent Photoluminescence Spanning Visible to Near-Infrared Wavelengths

2011 ◽  
Vol 24 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Colin M. Hessel ◽  
Dariya Reid ◽  
Matthew G. Panthani ◽  
Michael R. Rasch ◽  
Brian W. Goodfellow ◽  
...  
Keyword(s):  
Silicon Nanocrystals ◽  
Near Infrared ◽  
Size Dependent ◽  
Infrared Wavelengths
Sign in / Sign up

Export Citation Format

Share Document