Effect of Al substitution on Thermoelectric Performance of CuInTe2 compounds

2015 ◽  
Vol 1735 ◽  
Author(s):  
Chuandeng Hu ◽  
Kunling Peng ◽  
Guiwen Wang ◽  
Lijie Guo ◽  
Guoyu Wang ◽  
...  
Keyword(s):  
Transport Properties ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
First Principle ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Al Substitution ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Grain Surface

ABSTRACTThermoelectric CuIn1-xAlxTe2 compounds (x=0, 0.05, 0.1, 0.15, 0.50) have been synthesized by solid state reaction followed by spark plasma sintering. The influence of Al substitution on electrical and thermal transport properties has been investigated in the CuInTe2 compounds. It was found that the Seebeck coefficient and electrical conductivity is reduced by isovalent replacement of In with Al. Our first principle calculation indicates Al substitution leads to the widen band gap, the reduction in the number of degeneracy of valence band and the effective mass. Furthermore, a large reduction in thermal conductivity is achieved through the enhanced phonon scattering via point defect as well as the nano-sized particles observed between grain boundaries and on the grain surface. In spite of the reduced charge transport properties, an improved figure-of- merit ZT is achieved, reaching 0.8 at 800 K, 33% higher in comparison to the pure CuInTe2 compound.

scholarly journals Hf-Doping Effect on the Thermoelectric Transport Properties of n-Type Cu0.01Bi2Te2.7Se0.3

2020 ◽  
Vol 10 (14) ◽  
pp. 4875
Author(s):  
Jeong Yun Hwang ◽  
Sura Choi ◽  
Sang-il Kim ◽  
Jae-Hong Lim ◽  
Soon-Mok Choi ◽  
...  
Keyword(s):  
Carrier Mobility ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Mass Difference ◽  
Solidification Process ◽  
Transport Parameters ◽  
Plasma Sintering ◽  
Thermoelectric Transport Properties ◽  
Spark Plasma ◽  
Melt Solidification

Polycrystalline bulks of Hf-doped Cu0.01Bi2Te2.7Se0.3 are prepared via a conventional melt-solidification process and subsequent spark plasma sintering technology, and their thermoelectric performances are evaluated. To elucidate the effect of Hf-doping on the thermoelectric properties of n-type Cu0.01Bi2Te2.7Se0.3, electronic and thermal transport parameters are estimated from the measured data. An enlarged density-of-states effective mass (from ~0.92 m0 to ~1.24 m0) is obtained due to the band modification, and the power factor is improved by Hf-doping benefitting from the increase in carrier concentration while retaining carrier mobility. Additionally, lattice thermal conductivity is reduced due to the intensified point defect phonon scattering that originated from the mass difference between Bi and Hf. Resultantly, a peak thermoelectric figure of merit zT of 0.83 is obtained at 320 K for Cu0.01Bi1.925Hf0.075Te2.7Se0.3, which is a ~12% enhancement compared to that of the pristine Cu0.01Bi2Te2.7Se0.3.

Preparation and Thermoelectric Properties of Bi Doped Ca3Co4O9 Based Thermoelectric Materials

2018 ◽  
Vol 783 ◽  
pp. 144-147
Author(s):  
Jing Wang ◽  
Qin Chen ◽  
Xia Chun Zhu ◽  
Seok Je Lee ◽  
Kyoung Woo Park ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Sintering Process ◽  
Spin Entropy ◽  
Plasma Sintering ◽  
Spark Plasma

Polycrystalline Ca3-xBixCo4O9 samples have been prepared by solid-phase reaction followed by spark plasma sintering process. The thermoelectric properties have been systematically investigated from room temperature to near 1000K. It is found that the change of the carrier concentration leads to the change of resistivity, which is mainly associated with doping induced point defect phonon scattering. The change of the thermal potential mainly comes from the spin entropy. In addition, polycrystalline Ca3-xBixCo4O9 had a maximum figure of merit of 0.30 at 973 K, which was about 50% higher than Ca3Co4O9. It indicated that doping approach can effectively improve the thermoelectric performance of Ca3Co4O9+δ-based material.

scholarly journals Electronic structure and Thermoelectric Properties of Hybrid Organic-Inorganic Perovskites [NH3-(CH2)3-COOH]2CdCl4

2021 ◽  
Vol 22 (4) ◽  
pp. 750-755
Author(s):  
Elmustafa Ouaaka ◽  
Said Kassou ◽  
Mahmoud Ettakni ◽  
Salaheddine Sayouri ◽  
Ahmed Khmou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electronic Structure ◽  
Figure Of Merit ◽  
First Principle ◽  
Generalized Gradient ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Generalized Gradient Approximation ◽  
Thermoelectric Characteristic ◽  
Good Agreement

In this work, we conducted the first principle calculation of electronic structure and transport properties of [NH3-(CH2)3-COOH]2CdCl4 (Acid-Cd). The generalized gradient approximation is used in structural optimization and electronic structure. The theoretical band gap value found is in good agreement with experimental. Electronic thermal conductivity, electrical conductivity, Seebeck coefficient (S) and figure of merit (ZT) have been calculated using semi-local Boltzmann theory to predict the thermoelectric characteristic of the studied materials.

scholarly journals p-n Control of AlMgB14-Based Thermoelectric Materials by Metal Site Occupancy

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 632
Author(s):  
Takuya Fujima ◽  
Natsuki Shimizu ◽  
Hideki Arimatsu
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Site Occupancy ◽  
Mixture Ratio ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Metal Site ◽  
Plasma Sintering ◽  
Valence Electrons ◽  
Spark Plasma

The mechanism for the p-n control of AlMgB14-based thermoelectric material was investigated using Rietveld refinement and the first principle calculation. The p- and n-type AlMgB14-based thermoelectric materials were prepared by spark plasma sintering (SPS) with changing raw powder mixture ratio. Temperature dependence of Seebeck coefficient and electrical conductivity were different between the two types of samples. Seebeck coefficient shifted from positive to negative with increasing the number of valence electrons in the metal sites calculated by the metal site occupancy. The density of states and electron density distribution indicated that the electrons transfer from metal atoms to the B atoms.

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