Investigation of the thermoelectric properties of the PbTe-SrTe system

2010 ◽  
Vol 1267 ◽  
Author(s):  
Kanishka Biswas ◽  
Jiaqing He ◽  
Qichun Zhang ◽  
Guoyu Wang ◽  
Ctirad Uher ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Secondary Phase ◽  
Positive Sign ◽  
X Ray Diffraction ◽  
Rock Salt Structure ◽  
High Power Factor ◽  
Salt Structure ◽  
Diffraction Patterns ◽  
P Type ◽  
Type Conduction

AbstractPbTe-based materials are promising for efficient heat energy to electricity conversion. We present studies of the thermoelectric properties of the PbTe-SrTe system. X-ray diffraction patterns reveal that all the samples crystallize in the rock salt structure without noticeable secondary phase. Na2Te doping of the PbTe-SrTe materials resulting in a positive sign Hall coefficient indicating p-type conduction. Lattice thermal conductivity is significantly decreased with the insertion of SrTe in PbTe lattice. The ZT ∼ 1.3 of these materials is derived from their very low thermal conductivities and reasonably high power factor at 800 K.

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

Influence of GeP precipitates on the thermoelectric properties of P-type GeTe and Ge0.9−xPxSb0.1Te compounds

CrystEngComm ◽  
2018 ◽  
Vol 20 (41) ◽  
pp. 6449-6457 ◽  
Author(s):  
J. Rajeev Gandhi ◽  
Raja Nehru ◽  
Sheng-Ming Chen ◽  
Raman Sankar ◽  
Khasim Saheb Bayikadi ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Point Defects ◽  
Secondary Phase ◽  
Rich Phase ◽  
System P ◽  
Scattering Effects ◽  
P Type

The incorporation of P in GST forms the secondary GeP rich phase. The presence of secondary phase and point defects (Sb and P) enhanced the additional scattering effects in the system.

Annealing Effect on the Thermoelectric Properties of Undoped CoSb3

2006 ◽  
Vol 118 ◽  
pp. 565-570 ◽  
Author(s):  
Il Ho Kim ◽  
Jung Il Lee ◽  
Soon Chul Ur ◽  
Kyung Wook Jang ◽  
Good Sun Choi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Annealing Effect ◽  
Metallic Behavior ◽  
Arc Melting ◽  
P Type ◽  
Type Conduction

Binary skutterudite CoSb3 compounds were prepared by the arc melting and hot pressing processes and their thermoelectric properties were investigated at 300K-600K. Annealing effect was examined and it was correlated to phase transformation and homogenization. Thermoelectric properties of the arc-melted and hot-pressed CoSb3 were discussed and compared. Undoped CoSb3 prepared by the arc melting showed p-type conduction and metallic behavior at all temperatures examined. However, hot pressed specimens showed n-type conduction, possibly due to Sb evaporation. Thermoelectric properties were remarkably improved by annealing in vacuum and they were closely related to phase transitions.

Delafossite-CuAlO2 Thin Films Prepared by Thermal Annealing

2011 ◽  
Vol 13 ◽  
pp. 81-86 ◽  
Author(s):  
Hong Ying Chen ◽  
Ming Wei Tsai
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Transparent Conducting ◽  
Long Time ◽  
Hot Probe ◽  
Diffraction Patterns ◽  
P Type ◽  
Deposited Films ◽  
Partial Oxygen

Transparent conducting oxides (TCOs) are well known and have been widely used for a long time in optoelectronics industries. The most popular TCOs have n-type characteristics. However p-type material is not well established and examined. The delafossite-CuAlO2 is one of the p-type TCOs. In this paper, amorphous Cu-Al-O films were deposited onto (100) p-type silicon substrate by magnetron sputtering. After that, the films were annealed at 800°C for 2 h in different partial oxygen levels ranging from 5*10-5 to 1 atm with N2, air, and O2. X-ray diffraction patterns showed that as-deposited films were amorphous. In addition, delafossite-CuAlO2 (R m and P63/mmc phase) appeared at 800°C in N2, but monoclinic-CuO and spinel-CuAl2O4 phases existed in air and O2. The formation of delafossite-CuAlO2 phase can be explained with thermodynamics. The optoelectronic properties of delafossite-CuAlO2 films were also measured. The direct optical bandgap was around at 3.3 eV, which is comparable with literature data. The electrical conductivity was obtained to be 6.8*10-3 S/cm. The hot-probe method employed to measure the electrical property of the films, which indicates that delafossite-CuAlO2 films have p-type characteristics.

Study on Phases and Thermoelectric Properties of Bulk FexCo4-xSb12 Sintered by MM-SPS

2011 ◽  
Vol 179-180 ◽  
pp. 294-297
Author(s):  
Ke Gao Liu ◽  
Shi Lei
Keyword(s):  
Thermoelectric Properties ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Electrical Resistivities ◽  
Spark Plasma ◽  
P Type

Bulk FexCo4-xSb12 with x varies from 0.1 to 2.0 were prepared by mechanical milling (MM) and spark plasma sintering (SPS). The phases of the products were characterized by X-ray diffraction (XRD) and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk FexCo4-xSb12 are skutterudite. The electrical resistivities of the products increase first and then decrease. The Seebeck coefficients ( ) are negative when x=0.1 at 100 °C and 200 °C while positive at 300~500 °C. The products with x=0.5~2.0 at 100~500 °C are P type semiconducting materials due to their positive values. The thermal conductivities of most samples increase first and then decrease with x increasing and the maximum is up to 0.39 Wm-1K-1 when x=1.0. The ZT values at 200~500 °C increase first and then decrease with x increasing when x=0.1~1.0 and x=1.0~2.0 respectively and the maximum ZT value is 0.196 when x=1.5 at 400 °C.

scholarly journals Characterization of Ag-Doped p-Type SnO Thin Films Prepared by DC Magnetron Sputtering

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hoai Phuong Pham ◽  
Thanh Giang Le Thuy ◽  
Quang Trung Tran ◽  
Hoang Hung Nguyen ◽  
Huynh Tran My Hoa ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Carrier Scattering ◽  
Semiconductor Behavior ◽  
Type Semiconductor ◽  
Diffraction Patterns ◽  
P Type ◽  
Tin Monoxide

Crystalline structure and optoelectrical properties of silver-doped tin monoxide thin films with different dopant concentrations prepared by DC magnetron sputtering are investigated. The X-ray diffraction patterns reveal that the tetragonal SnO phase exhibits preferred orientations along (101) and (110) planes. Our results indicate that replacing Sn2+ in the SnO lattice with Ag+ ions produces smaller-sized crystallites, which may lead to enhanced carrier scattering at grain boundaries. This causes a deterioration in the carrier mobility, even though the carrier concentration improves by two orders of magnitude due to doping. In addition, the Ag-doped SnO thin films show a p-type semiconductor behavior, with a direct optical gap and decreasing transmittance with increasing Ag dopant concentration.

Microstructure and Thermoelectric Properties of p-Type Bi0.5Sb1.5Te3 and n-Type Bi2Te2.7Se0.3 Films Deposited by Pulsed Laser Ablation

2001 ◽  
Vol 691 ◽  
Author(s):  
Raghuveer S. Makala ◽  
K. Jagannadham ◽  
B.C. Sales ◽  
Hsin Wang
Keyword(s):  
Laser Ablation ◽  
Thermoelectric Properties ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Uniform Thickness ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
X Ray ◽  
Crystal Perfection ◽  
P Type

ABSTRACTThin films of p-type Bi0.5Sb1.5Te3, n-type Bi2Te2.7Se0.3 and n-type with SbI3 doping were deposited on mica substrates using Nd-YAG pulsed laser ablation at temperatures ranging from 300°C to 500°C. These films were characterized using X-ray diffraction, SEM and TEM. X-ray mapping and EDS were used to determine the composition. The films showed uniform thickness and high crystalline quality with a preferred (00n) alignment with the substrates. The film quality in terms of composition and crystal perfection is studied as a function of growth temperature. It was found that films deposited at 350°C gave improved crystallinity and thermoelectric characteristics. The Seebeck coefficient, electrical resistivity and Hall mobility were measured as a function of temperature and compared with the measurements on the bulk. Correlation of thermoelectric properties with microstructure is discussed.

scholarly journals Structures of AlN/VN Superlattices with Different AlN Layer Thicknesses

2002 ◽  
Vol 17 (5) ◽  
pp. 1224-1231 ◽  
Author(s):  
Quan Li ◽  
I. W. Kim ◽  
S. A. Barnett ◽  
L. D. Marks
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Structural Model ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
Rock Salt Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Salt Structure

AlN/VN superlattices with different periods were studied using x-ray diffraction and transmission electron microscopy (TEM). A phase transformation of the AlN from an epitaxially stabilized rock-salt structure to a hexagonal wurtzite structure was observed for an AlN layer thickness greater than 4 nm. A structural model is proposed on the basis of TEM results for the orientation of the transformed phase. The VN layer grown on top of the hexagonal AlN was observed to be reoriented compared to that in the stabilized B1-AlN/VN. The VN nucleated by taking the w-AlN(002) plane as its (111) plane instead of the (002) plane.

ELECTRICAL CONDUCTING AND THERMOELECTRIC PROPERTIES OF Ba4Na2Nb10O30−Ba3NaLaNb10O30 SYSTEM

1990 ◽  
Vol 04 (10) ◽  
pp. 681-688
Author(s):  
MASAYUKI TSUKIOKA ◽  
YASUO TANOKURA ◽  
MASAZI SHIMAZU ◽  
SHINICHIRO KUROIWA ◽  
SADAO TSUTSUMI
Keyword(s):  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Solid Solutions ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Electrical Conducting ◽  
P Type

Ceramic samples of BNN-BNLN ( Ba 4 Na 2 Nb 10 O 30− Ba 3 NaLaNb 10 O 30) system were prepared in flowing N 2 gas at about 1410°C, which has been confirmed to have continuous solid solutions over the whole range of BNN-BNLN system by X-ray diffraction measurement. Electrical resistivity and Seebeck coefficient measurements were carried out at temperatures from 77 K to 773 K and from 60 K to 200 K, respectively for the samples of different composition belonging to the BNN-BNLN system. These experiments revealed that all these materials were extrinsic semiconductors and change from p-type semiconductors to n-type during the process of rising temperature.

scholarly journals Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi2Te3 matrix

2019 ◽  
Vol 10 ◽  
pp. 634-643 ◽  
Author(s):  
Srashti Gupta ◽  
Dinesh Chandra Agarwal ◽  
Bathula Sivaiah ◽  
Sankarakumar Amrithpandian ◽  
Kandasami Asokan ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Transmission Electron ◽  
High Power Factor ◽  
Different Temperatures ◽  
High Figure ◽  
Filtering Effect ◽  
P Type ◽  
20 Nm

The present study aims to see the enhancement in thermoelectric properties of bismuth telluride (Bi2Te3) annealed at different temperatures (573 and 773 K) through silver (Ag) nano-inclusions (0, 2, 5, 10, 15 and 20 wt %). Transmission electron microscopy (TEM) images of Ag incorporated in Bi2Te3 annealed at 573 K shows tubular, pentagonal, trigonal, circular and hexagonal nanoparticles with sizes of 6–25 nm (for 5 wt % Ag ) and 7–30 nm (for 20 wt % Ag). Ag incorporated in Bi2Te3 annealed at 773 K shows mainly hexagonally shaped structures with particle sizes of 2–20 nm and 40–80 nm (for 5 wt % Ag) and 10–60 nm (for 20 wt % Ag). Interestingly, the samples annealed at 573 K show the highest Seebeck coefficient (S, also called thermopower) at room temperature (p-type behavior) for 5% Ag which is increased ca. five-fold in comparison to Ag-free Bi2Te3, whereas for samples with the same content (5% Ag) annealed at 773 K the increment in thermopower is only about three-fold with a 6.9-fold enhancement of the power factor (S 2σ). The effect of size and shape of the nanoparticles on thermoelectric properties can be understood on the basis of a carrier-filtering effect that results in an increase in thermopower along with a control over the reduction in electrical conductivity to maintain a high power factor yielding a high figure of merit.

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