Thermoelectric properties of Ni-doped CuInTe2 (original) (raw)

Thermoelectric transport properties of CuFeInTe3

Journal of Alloys and Compounds, 2015

In this paper we report on the preparation of CuFeInTe 3 and its thermoelectric properties. Optical diffuse reflectance and Raman scattering spectroscopies, as well as X-ray powder diffraction were also carried out. Unprecedented for CuFeInTe 3 , a direct and an indirect bang gap were found from its absorption spectrum. From Hall effect measurements at 300 K the carrier concentration (n), electrical conductivity () and mobility (µ) were determined. In order to investigate whether this material is suitable for thermoelectric applications, the Seebeck coefficient (S), the thermal conductivity (κ) and as a function of temperature were measured. The measurements of Hall and Seebeck coefficients showed that alloying CuInTe 2 with Fe 2+ produces a change from the original p-type to n-type conductivity and causes a decrease in κ value, while leaving  unchanged. Relatively large S values were found for CuFeInTe 3 , with respect to CuInTe 2 , which were explained on the basis of a probable electron effective mass increase due to Fe 2+ incorporation. It was also found, that thermal and electrical conductivitiesdecrease with increasing temperature in the range between 300 and 450 K, while the figure of merit (zT) reaches values of 0.075 and 0.126 at 300 and 450 K respectively. Thus, zT of CuFeInTe 3 increases with temperature, reaching values larger than those reported for CuInTe 2 .

First-principles study of thermoelectric properties of CuI

Materials Research Express, 2014

Theoretical investigations of the thermoelectric properties of CuI have been carried out employing first-principles calculations followed by the calculations of transport coefficients based on Boltzmann transport theory. Among the three different phases of CuI, viz. zinc-blende, wurtzite and rock salt, the thermoelectric power factor is found to be the maximum for the rock salt phase. We have analysed the variations of Seebeck coefficients and thermoelectric power factors on the basis of calculated electronic structures near the valence band maxima of these phases.

Ab Initio Investigation on the Thermoelectric Properties of γ-CuI for Thermoelectric Device Applications

Semi-classical transport thermoelectric properties of γ-CuI are investigated using density functional theory (DFT) calculation containing Boltzmann transport equations. The Tran-Blaha modified Becke-Johnson potential (Tb-mBJ) approximation is used as the exchange correlation potential. Thermoelectric properties such as, Seebeck coefficient , electrical conductivity, thermal conductivity, power factor, figure of merit, thermoelectric voltage and thermoelectric conversion efficiency are discussed with constant relaxation time as a function of chemical potential. This is because the chemical potential is directly related with the carrier concentration and temperature. These parameters are strongly dependent on the doping level and temperature. The maximum range of figure of merit (0.8-1.0) and conversion efficiency (93%) is found to be in the range of chemical potential.0.032-0.036 Ry. The active thermoelectric region of γ-CuI is observed in the range of temperature from 300 K to 450 K. Hence, γ-CuIbehaves excellent thermoelectric material for heat generation and extraction applications.

Thermoelectric properties of Cu 3 SbSe 3 with intrinsically ultralow lattice thermal conductivity

J. Mater. Chem. A, 2014

We report the synthesis, characterization and evaluation of the thermoelectric properties of Cu 3 SbSe 3 with a view to explore its utility as an useful thermoelectric material due to its intrinsically low thermal conductivity. Cu 3 SbSe 3 was synthesized employing a solid state reaction process followed by spark plasma sintering, and the synthesized material was extensively characterized for its phase, composition and structure, which suggested formation of a single-phase. The measured electrical transport properties of Cu 3 SbSe 3 indicated p-type conduction in this material. The electrical transport behavior agrees well with that predicted theoretically using first-principle density-functional theory calculations, employing generalized gradient approximation. The measured thermal conductivity was found to be 0.26 W m À1 K À1 at 550 K, which is the lowest reported thus far for Cu 3 SbSe 3 and is among the lowest for state-of-the-art thermoelectric materials. Despite its ultralow thermal conductivity coupled with a moderate Seebeck coefficient, the calculated value of its thermoelectric figure-of-merit was found to be exceptionally low (<0.1), which was primarily attributed to its low electrical conductivity. Nevertheless, it is argued that Cu 3 SbSe 3 , due its environmentally-friendly constituent elements, ultralow thermal conductivity and moderate thermopower, could be a potentially useful thermoelectric material as the power factor can be favorably tailored by tuning the carrier concentration using suitable metallic dopants.

Investigations on Bi Doped Cu2Se Prepared by Solid State Reaction Technique for Thermoelectric Applications

Energies

The influence of Bi doping on the structural and thermoelectric properties of Cu2Se is presented in this work. Cu2−xBixSe (x = 0.00, 0.004, 0.008, 0.012) samples were prepared using conventional solid-state reaction techniques. According to room temperature XRD results, Cu2−xBixSe samples have a monoclinic crystal structure. Doping Bi to the Cu site acts as a donor, lowering the hole concentration, except for the sample with x = 0.004. The resistivity of the Cu2−xBixSe sample increases with an increase in Bi content. Seebeck coefficient data confirm that the holes are the charge carriers in Cu2−xBixSe samples. At 700 K, the Cu1.988Bi0.012Se sample has the highest power factor of 1474 μWm−1K−2, showing great potential in developing high-performance Cu2Se based thermoelectric materials.

Electronic structures and thermoelectric properties of solid solutions CuGa1−xInxTe2: A first-principles study

Chinese Physics B, 2014

Thermoelectric properties of La or Ce-doped Bi 2 Te 3 alloys were systematically investigated by ab initio calculations of electronic structures and Boltzmann transport equations. The Seebeck coefficient of p-type LaBi 7 Te 12 and La 2 Bi 6 Te 12 was larger than that of Bi 2 Te 3 , because La doping increased the effective mass of carriers. On the other hand, the electrical conductivity of LaBi 7 Te 12 and La 2 Bi 6 Te 12 decreased, which caused a reduction of power factor of these La-doped Bi 2 Te 3 alloys in comparison with Bi 2 Te 3. The influence of Ce doping on the band structure and thermoelectric properties of Bi 2 Te 3 was similar to that of La doping. The theoretical calculation provided an insight into the transport properties of La or Cedoped Bi 2 Te 3-based thermoelectric materials.

Thermoelectric properties of CuCrSe[sub 2]

2013

The efficient conversion of heat into electricity using a thermoelectric approach requires high performance materials with the thermoelectric figure of merit ZT $ 1. Here we report on bulk CuCrSe 2 , which exhibits a very high ZT $ 1 at 773 K. The titled compound exhibits an electrical resistivity of 2.8mUcm,aSeebeckcoefficientof2.8 mU cm, a Seebeck coefficient of 2.8mUcm,aSeebeckcoefficientof160 mV K À1 , together with very low thermal conductivity $7 mW cm À1 K À1 at 773 K. The very low thermal conductivity of bulk CuCrSe 2 is attributed to phonon scattering by various sources such as (i) superionic Cu ions between the CrSe 2 layers, (ii) nanoscale precipitates in the bulk and (iii) natural grain boundaries due to the layered structure of the material. This unusual combination of thermoelectric properties for CuCrSe 2 suggests that it is an ideal example of the phonon glass and electron crystal approach.

Thermoelectric properties of Cu-doped n-type (Bi2Te3)0.9–(Bi2−xCuxSe3)0.1(x=0–0.2) alloys

Journal of Solid State Chemistry, 2007

N-type Bi 2 Te 2.85 Se 0.15 thermoelectric materials were prepared by liquid phase growth (LPG) using a sliding boat, a simple and short fabrication process for Bi 2 Te 3-related materials. Cu was selected as a donor dopant, and its effect on thermoelectric properties was investigated. Thick sheets and bars of Cu x Bi 2 Te 2.85 Se 0.15 (x = 0-0.25) of 1-2 mm in thickness were obtained using the process. X-ray diffraction patterns and scanning electron micrographs showed that the in-plane direction tended to correspond to the hexagonal c-plane, which is the preferred direction for thermoelectric conversion. Cu-doping was effective in controlling conduction type and carrier (electron) concentration. The conduction type was p-type for undoped Bi 2 Te 2.85 Se 0.15 and became n-type after Cu-doping. The Hall carrier concentration was increased by Cu-doping. Small resistivity was achieved in Cu 0.02 Bi 2 Te 2.85 Se 0.15 owing to an optimized amount of Cu-doping and high crystal orientation. As a result, the maximum power factor near 310 K for Cu 0.02 Bi 2 Te 2.85 Se 0.15 was approximately 4 9 10 À3 W/K 2 m and had good reproducibility. Furthermore, the thermal stability of Cu 0.02 Bi 2 Te 2.85 Se 0.15 was also confirmed by thermal cycling measurements of electrical resistivity. Thus, n-type Bi 2 Te 2.85 Se 0.15 with a large power factor was prepared using the present LPG process.

Thermoelectric properties of Cu2S obtained by high temperature synthesis and sintered by IHP method

Ceramics International, 2020

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Ab initio study of thermoelectric transport properties of pure and doped quaternary compounds

Physical Review B, 2010

Recent experiments on thermoelectric characterization of doped quaternary compounds of sattanite or kesterite-type Cu 2 ZnSnSe 4 , Cu 2 ZnSnS 4 , and Cu 2 CdSnSe 4 , show promise for their use as bulk thermoelectrics. In this paper we present and discuss the energetic, electronic, and transport properties of several tetrahedrally bonded quaternary compounds Cu 2 QSnX 4 , where Q = Zn, Cd; X =S,Se,Te and their alloyed/doped structures, Cu doped at Q sites and M doped ͑M =Al,Ga,In͒ at Sn sites, for elucidating their thermoelectric performance. In our calculations, using density-functional theory and Boltzmann transport equations, we determine Seebeck coefficients, conductivities, power factors, a simple measure "maximum" ZT for each compound at experimentally amenable doping levels. Based on the electronic-structure and transport property calculations, we conclude that the base compounds and several doped compounds show similar potential as thermoelectric materials to the experimentally characterized one.