scholarly journals Thermal conductivity of GaAs nanowires studied by micro-Raman spectroscopy combined with laser heating

2010 ◽  
Vol 97 (26) ◽  
pp. 263107 ◽  
Author(s):  
Martin Soini ◽  
Ilaria Zardo ◽  
Emanuele Uccelli ◽  
Stefan Funk ◽  
Gregor Koblmüller ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Laser Heating ◽  
Micro Raman Spectroscopy ◽  
Gaas Nanowires

Micro-Raman spectroscopy for the detection of stacking fault density in InAs and GaAs nanowires

2017 ◽  
Vol 96 (16) ◽  
Author(s):  
Rawa Tanta ◽  
Caroline Lindberg ◽  
Sebastian Lehmann ◽  
Jessica Bolinsson ◽  
Miguel R. Carro-Temboury ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Stacking Fault ◽  
Micro Raman Spectroscopy ◽  
Fault Density ◽  
Gaas Nanowires

Measurement of In-Plane Thermal Conductivity of Ultrathin Films Using Micro-Raman Spectroscopy

2014 ◽  
Vol 18 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Zhe Luo ◽  
Han Liu ◽  
Bryan T. Spann ◽  
Yanhui Feng ◽  
Peide Ye ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Ultrathin Films ◽  
Micro Raman Spectroscopy

Performance Analysis of Micro-Raman Spectroscopy Models for Thermal Conductivity Calculation

2021 ◽  
Author(s):  
Taher Meydando ◽  
Nazli Donmezer
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Phonon Scattering ◽  
Raman Laser ◽  
Current Approach ◽  
Slab Model ◽  
Boltzmann Transport ◽  
Micro Raman Spectroscopy ◽  
Thermal Conductivities

Abstract Micro-Raman spectroscopy has been preferred recently to measure the thermal conductivity of thin-films due to its nondestructive and non-contact nature. However, the thermal size effects originating from both localized heat generation from Raman laser and phonon scattering at boundaries may cause erroneous estimation of the thermal conductivities with the current approach. In this study, the gray phonon Boltzmann transport equation (BTE) is solved to improve the results of micro-Raman thermal conductivity measurements. Due to the frequency independence of single phonon mode in the gray BTE model, our method stays ahead of most theoretical methods in calculation time while giving adequate agreement with the literature data. The improved thermal conductivities are evaluated at various laser powers and focal lengths. Subsequently, the values of thermal conductivities are compared with a simple slab model in which the deduction of thermal conductivity in sub-micron thicknesses is calculated using reduced heat flux through the slab resulting from phonon directional energy densities. The results show that subsequent errors are present in measuring the thermal conductivity of relatively thick, thin films with this technique which are noticed by comparing with the simple slab model. Finally, a virtual micro-Raman thermography experiment is developed, and its validity is verified by the same slab model.

scholarly journals Probing Phonons in Nonpolar Semiconducting Nanowires with Raman Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Kofi W. Adu ◽  
Martin D. Williams ◽  
Molly Reber ◽  
Ruwantha Jayasingha ◽  
Humberto R. Gutierrez ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Phenomenological Model ◽  
Line Shape ◽  
Laser Heating ◽  
Acoustic Phonon ◽  
Phonon Confinement ◽  
Semiconducting Nanowires ◽  
Recent Developments ◽  
Raman Probe

We present recent developments in Raman probe of confined optical and acoustic phonons in nonpolar semiconducting nanowires, with emphasis on Si and Ge. First, a review of the theoretical spatial correlation phenomenological model widely used to explain the downshift and asymmetric broadening to lower energies observed in the Raman profile is given. Second, we discuss the influence of local inhomogeneous laser heating and its interplay with phonon confinement on Si and Ge Raman line shape. Finally, acoustic phonon confinement, its effect on thermal conductivity, and factors that lead to phonon damping are discussed in light of their broad implications on nanodevice fabrication.

Laser Heating in Porous Silicon Studied by Micro-Raman Spectroscopy

2000 ◽  
Vol 182 (1) ◽  
pp. 331-334 ◽  
Author(s):  
S. Manotas ◽  
F. Agull�-Rueda ◽  
J.D. Moreno ◽  
F. Ben-Hander ◽  
R. Guerrero-Lemus ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Porous Silicon ◽  
Laser Heating ◽  
Micro Raman Spectroscopy

Study of thermal conductivity in two-dimensional Bi2Te3 from micro-Raman spectroscopy

2021 ◽  
Vol 01 ◽  
Author(s):  
Manavendra P. Singh ◽  
Sumarlang Ryntathiang ◽  
Sivarama Krishnan ◽  
Pramoda K. Nayak
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Temperature Coefficient ◽  
Raman Spectra ◽  
Heat Dissipation ◽  
Surface States ◽  
Power Coefficient ◽  
Great Promise ◽  
Temperature Dependent ◽  
Micro Raman Spectroscopy

Background: Topological insulator (TI), Bi2Te3 is a new class of the quantum materials. Having ultralow dissipation surface states, TIs hold great promise toward different potential applications. Micro-Raman spectroscopy is a conventional and non-destructive technique, which has been widely used to characterize the structural and electronic properties of the thermoelectric materials. Objective: To study power dependent and temperature dependent Raman spectra of Bi2Te3 nano flakes on SiO2/Si substrate to estimate the temperature coefficient and thermal conductivity of these flakes for possible application of this material in thermoelectrics. Method: Bi2Te3 flakes of different thicknesses were mechanically exfoliated from high quality bulk Bi2Te3 crystal using scotch tape on 300 nm SiO2/ Si substrates. The power dependent and temperature dependent Raman spectra were acquired with the help of HORIBA LabRAM confocal micro-Raman system in a back scattering geometry. Result: . The observed power dependent and temperature dependent Raman spectra of Bi2Te3 nano flakes follow the same trend as discussed in various literatures. From temperature coefficient and power coefficient values, the in plane thermal conductivity has been estimated, which is found to be in the order of 10 2 W/m-K. The enhancement in the thermal conductivity suggests that the underlying substrate significantly affects the heat dissipation of the Bi2Te3 flake based on the coupling strength with Bi2Te3. Conclusion: This work provides a good platform to understand the role of substrate on the thermal conductivity of exfoliated Bi2Te3 nano flakes and this study can be extended to other substrates.

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