Analytical Model of Carbon Nanotube Electrostatics: Density of States, Effective Mass, Carrier Density, and Quantum Capacitance

2007 ◽  
Author(s):  
Deji Akinwande ◽  
Yoshio Nishi ◽  
H.-S. Philip Wong
Keyword(s):  
Carbon Nanotube ◽  
Effective Mass ◽  
Analytical Model ◽  
Density Of States ◽  
Carrier Density ◽  
Quantum Capacitance

scholarly journals Effect of band structure adjustment based of Cu site on the thermoelectric properties of BiCuSeO

2021 ◽  
Author(s):  
Bo Feng
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Effective Mass ◽  
Valence Band ◽  
Thermoelectric Properties ◽  
Density Of States ◽  
First Principles Calculation ◽  
Temperature Range ◽  
Ti Doping

Abstract The effect of Ti doped at Cu site on the thermoelectric properties of BiCuSeO was studied by experimental method and first principles calculation. The results show that Ti doping can cause the lattice contraction and decrease the lattice constant. Ti doping can increase the band gap and lengthen the Cu/Ti-Se bond, resulting in the decrease of carrier concentration. Ti doping can reduce the effective mass and the Bi-Se bond length, correspondingly improve the carrier mobility. Ti doping can decrease the density of states of Cu-3d and Se-4p orbitals at the top of valence band, but Ti-4p orbitals can obviously increase the density of states at the top of valence band and finally increase the electrical conductivity in the whole temperature range. With the decrease of effective mass, Ti doping would reduce the Seebeck coefficient, but the gain effect caused by the increase of electrical conductivity is more than the benefit reduction effect caused by the decrease of Seebeck coefficient, and the power factor shows an upward trend. Ti doping can reduce Young's modulus, lead to the increase of defect scattering and strain field, correspondingly reduce the lattice thermal conductivity and total thermal conductivity. It is greatly increased for the ZT values in the middle and high temperature range, with the highest value of 1.04 at 873 K.

Rationally optimized carrier effective mass and carrier density lead to high average ZT value in n-type PbSe

2021 ◽  
Author(s):  
Yu Xiao ◽  
Wei Liu ◽  
Yang Zhang ◽  
Dongyang Wang ◽  
Haonan Shi ◽  
...  
Keyword(s):  
Transport Properties ◽  
Effective Mass ◽  
Electrical Transport ◽  
Carrier Density ◽  
Electrical Transport Properties ◽  
Carrier Effective Mass ◽  
Thermoelectric Parameters

Among these intricately coupled thermoelectric parameters, the carrier effective mass (m*) and carrier density (n) are two key parameters to determine the electrical transport properties. To enhance the broad-temperature thermoelectric...

Nondimensional Analysis of Interfacial Stresses of Wavy CNT/Polymer Composites

2008 ◽  
Author(s):  
K. Yazdchi ◽  
M. Salehi
Keyword(s):  
Carbon Nanotube ◽  
Polymer Composites ◽  
Analytical Model ◽  
Stress Transfer ◽  
Interfacial Shear ◽  
Linear Regression Method ◽  
Shear Stresses ◽  
Interfacial Stresses ◽  
Single Walled Carbon Nanotube ◽  
Reinforced Polymer

In this paper, with introducing a new simplified 3-D Representative Volume Element (RVE) for a wavy carbon nanotube (CNT), an analytical model has been developed to study the stress transfer in single-walled carbon nanotube (SWNT) reinforced polymer composites (NRPCs). The model is capable of predicting axial as well as interfacial shear stresses, along a wavy CNT embedded in a matrix. Based on the pullout modeling technique, the effects of waviness, wavelength and matrix modulus on axial and interfacial shear stresses have also been analyzed in details also using the statistical multiple non-linear regression method, the best-fitted functions for the interfacial stresses of CNT/polymer composites are obtained. The results of the present analytical model are in good agreements when compared with the corresponding results for straight NTs.

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