Determining the Thermal Conductivity of W/B4C Multilayer Structures Using Photothermal Deflection Spectroscopy

Author(s):  
Michael Moorhead ◽  
C. Thomas Avedisian ◽  
Alexander Kazimirov
2010 ◽  
Vol 434-435 ◽  
pp. 783-786 ◽  
Author(s):  
Gui Hua Peng ◽  
Zhen Hua Liang ◽  
Feng Qi Lu ◽  
Qian Liu ◽  
Wen Lan Li

Silicon nitride ceramics with MgSiN2 as additives were sintered by hot pressing at 1600° ~ 1750 °C for 1-12 h under uniaxial pressure of 20 MPa. The specimens were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and photothermal deflection spectroscopy. After sintered at 1750°C for 1 h, the thermal conductivity of the material was 90 W·m-1·K-1. The thermal conductivity could remarkably increase to 120 W·m-1·K-1 by prolonging the dwell time from 1 h to 12 h. The present work demonstrated that MgSiN2 additives were effective to improve the thermal conductivity of β-Si3N4 ceramic.


2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Faycel Saadallah ◽  
Neila Jebbari ◽  
Najoua Kammoun ◽  
Noureddine Yacoubi

Photothermal deflection spectroscopy (PDS) is carried out in order to investigate thermal and optical properties of Al doped In2S3. The influence of thermal annealing on its gap energy as well as its thermal properties is revealed. In this way, we notice that thermal conductivity is increased and the gap energy is reduced. These features are probably due to the improvement of the crystalline structure of the sample.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
S. Ktifa ◽  
M. Ghrib ◽  
F. Saadallah ◽  
H. Ezzaouia ◽  
N. Yacoubi

We have studied the optical properties of nanocrystalline silicon (nc-Si) film deposited by plasma enhancement chemical vapor deposition (PECVD) on porous aluminum structure using, respectively, the Photothermal Deflection Spectroscopy (PDS) and Photoluminescence (PL). The aim of this work is to investigate the influence of anodisation current on the optical properties of the porous aluminum silicon layers (PASL). The morphology characterization studied by atomic force microscopy (AFM) technique has shown that the grain size of (nc-Si) increases with the anodisation current. However, a band gap shift of the energy gap was observed.


2008 ◽  
Vol 103 (9) ◽  
pp. 094906 ◽  
Author(s):  
Adam R. Krause ◽  
Charles Van Neste ◽  
Larry Senesac ◽  
Thomas Thundat ◽  
Eric Finot

1991 ◽  
pp. 269-272
Author(s):  
J. Serra ◽  
J. Andreu ◽  
G. Sardin ◽  
C. Roch ◽  
J.M. Asensi ◽  
...  

1992 ◽  
Vol 283 ◽  
Author(s):  
S. Q. Gu ◽  
J. M. Viner ◽  
P. C. Taylor ◽  
M. J. Williams ◽  
W. A. Turner ◽  
...  

ABSTRACTPhotoluminescence (PL) has been investigated in hydrogenated microcrystalline silicon (μc-Si:H) samples as a function of boron doping for films prepared by remote plasma enhanced chemical vapor deposition. When the dark conductivity a is below about 10-5 S/cm, the PL spectra exhibit a shape which is close to that of the so-called band tail PL in undoped hydrogenated amorphous silicon (a-Si:H) at 77 K. When a increases, the PL intensity decreases at 77 K. For samples with a on the order of 10-3 S/cm, the PL spectra show only a narrow, low energy PL band which peaks around 0.8–0.9 eV. In these samples, the PL at higher energy is essentially not observable. This trend is similar to that which occurs in doped a-Si:H. However, for higher doping levels (σ ∼ 1 S/cm) the PL in μc-Si:H, although very weak, exhibits a broad band which contains intensity at higher energies. The absorption spectra in these samples, as measured by photothermal deflection spectroscopy (PDS), show the same relationships with the corresponding PL spectra as do the PDS spectra in doped a-Si:H.


2009 ◽  
Vol 94 (13) ◽  
pp. 131913 ◽  
Author(s):  
Dino Ferizović ◽  
Lindsay K. Hussey ◽  
Ying-Sheng Huang ◽  
Martin Muñoz

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