Pump-Probe Experimental Study of Phonon Reflectivity at an Interface and Phonon Relaxation Time

Author(s):  
Ronggui Yang ◽  
Xiaoyuan Chen ◽  
Aaron Schmidt ◽  
Gang Chen

Heat transfer in nanostructures differs significantly from that in macrostructures because of classical and quantum size effects on energy carriers, i.e., phonons, electrons, and photons [1–3]. Understanding thermal transport in nanostructures is of fundamental importance to a variety of technologies, including thermal management of nanoelectronics and optoelectronics, energy conversion, nanofabrication, and sensor development. A better understanding of the energy transport at nanoscale calls for both simulations and experimental techniques on thermal transport in nanostructures.

1991 ◽  
Vol 16 (6) ◽  
pp. 623-638 ◽  
Author(s):  
P.A. Badoz ◽  
F. Arnaud d'Avitaya ◽  
E. Rosencher

1983 ◽  
Vol 44 (C10) ◽  
pp. C10-375-C10-378 ◽  
Author(s):  
P. Ahlqvist ◽  
P. de Andrés ◽  
R. Monreal ◽  
F. Flores

1968 ◽  
Vol 96 (9) ◽  
pp. 61-86 ◽  
Author(s):  
B.A. Tavger ◽  
V.Ya. Demikhovskii

2021 ◽  
Vol 11 (13) ◽  
pp. 5933
Author(s):  
Wei-Jen Chen ◽  
I-Ling Chang

This study investigated the thermal transport behaviors of branched carbon nanotubes (CNTs) with cross and T-junctions through non-equilibrium molecular dynamics (NEMD) simulations. A hot region was created at the end of one branch, whereas cold regions were created at the ends of all other branches. The effects on thermal flow due to branch length, topological defects at junctions, and temperature were studied. The NEMD simulations at room temperature indicated that heat transfer tended to move sideways rather than straight in branched CNTs with cross-junctions, despite all branches being identical in chirality and length. However, straight heat transfer was preferred in branched CNTs with T-junctions, irrespective of the atomic configuration of the junction. As branches became longer, the heat current inside approached the values obtained through conventional prediction based on diffusive thermal transport. Moreover, directional thermal transport behaviors became prominent at a low temperature (50 K), which implied that ballistic phonon transport contributed greatly to directional thermal transport. Finally, the collective atomic velocity cross-correlation spectra between branches were used to analyze phonon transport mechanisms for different junctions. Our findings deeply elucidate the thermal transport mechanisms of branched CNTs, which aid in thermal management applications.


1997 ◽  
Vol 229 (6) ◽  
pp. 401-405 ◽  
Author(s):  
A. Crépieux ◽  
C. Lacroix ◽  
N. Ryzhanova ◽  
A. Vedyayev

2006 ◽  
Vol 100 (11) ◽  
pp. 114905 ◽  
Author(s):  
M. Cattani ◽  
M. C. Salvadori ◽  
A. R. Vaz ◽  
F. S. Teixeira ◽  
I. G. Brown

1993 ◽  
Vol 97 (37) ◽  
pp. 9493-9498 ◽  
Author(s):  
Ladislav Kavan ◽  
Tiziana Stoto ◽  
Michael Graetzel ◽  
Donald Fitzmaurice ◽  
Valery Shklover

1992 ◽  
Vol 283 ◽  
Author(s):  
R. Tsu ◽  
L. Ioriatti ◽  
J. F. Harvey ◽  
H. Shen ◽  
R. A. Lux

ABSTRACTThe reduction of the dielectric constant due to quantum confinement is studied both experimentally and theoretically. Angle resolved ellipsometry measurements with Ar- and He-Ne-lasers give values for the index of refraction far below what can be accounted for from porosity alone. A modified Penn model to include quantum size effects has been used to calculate the reduction in the static dielectric constant (ε) with extreme confinement. Since the binding energy of shallow impurities depends inversely on ε2, the drastic decrease in the carrier concentration as a result of the decrease in ε leads to a self-limiting process for the electrochemical etching of porous silicon.


2006 ◽  
Vol 89 (18) ◽  
pp. 183109 ◽  
Author(s):  
Tie-Zhu Han ◽  
Guo-Cai Dong ◽  
Quan-Tong Shen ◽  
Yan-Feng Zhang ◽  
Jin-Feng Jia ◽  
...  

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