P-Type Transparent Conductivity of Cu1-xAlS2 (x = 0 ~ 0.08)

2008 ◽  
Vol 368-372 ◽  
pp. 666-668 ◽  
Author(s):  
Min Ling Liu ◽  
Fu Qiang Huang ◽  
Li Dong Chen
Keyword(s):  
Optical Properties ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Hall Mobility ◽  
Room Temperature ◽  
Electrical And Optical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

A series of Cu1-xAlS2 (x = 0 ~ 0.08) bulk samples were synthesized by spark plasma sintering. The electrical and optical properties were investigated. P-type conductions for all samples were confirmed by both positive Seebeck coefficient and Hall coefficient. Bulk undoped CuAlS2 had a high conductivity of about 0.9 S/cm with a large band gap of 3.4 eV at room temperature. For vacancy-doped in Cu site, the carrier concentration was highly enhanced, reaching 1.7 × 1019 cm-3 for 8 mol% doped sample, and without decreasing the bang gap. The introduction of vacancies destroys the continuity of Cu-S network, which decreases the Hall mobility.

scholarly journals Optical and Transport Properties of p-Type GaAs

2012 ◽  
Vol 36 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Mehnaz Sharmin ◽  
Shamima Choudhury ◽  
Nasrin Akhtar ◽  
Tahmina Begum
Keyword(s):  
Light Intensity ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Hall Mobility ◽  
Room Temperature ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
Band Gap Energy ◽  
Hall Effect Measurements ◽  
P Type

Electrical properties such as electrical resistivity, Hall coefficient, Hall mobility, carrier concentration of p-type GaAs samples were studied at room temperature (300 K). Resistivity was  found to be of the order of 5.6 × 10-3?-cm. The Hall coefficient (RH) was calculated to be 7.69 × 10-1cm3/C and Hall mobility (?H) was found to be 131cm2/V-s at room temperature from Hall effect   measurements. Carrier concentration was estimated to be 8.12 × 1018/cm3 and the Fermi level was calculated directly from carrier density data which was 0.33 eV. Photoconductivity measurements  were carried on by varying sample current, light intensity and temperature at constant chopping     frequency 45.60 Hz in all the cases mentioned above. It was observed that within the range of sample current 0.1 - 0.25mA photoconductivity remains almost constant at room temperature 300K and it was found to be varying non-linearly with light intensity within the range 37 - 12780 lux. Photoconductivity was observed to be increasing linearly with temperature between 308 and 428 K. Absorption coefficient (?) of the samples has been studied with variation of wavelength (300 -  2500 nm). The value of optical band gap energy was calculated between 1.34 and 1.41eV for the material from the graph of (?h?)2 plotted against photon energy. The value of lattice parameter (a) was found to be 5.651 by implying X-ray diffraction method (XRD).DOI: http://dx.doi.org/10.3329/jbas.v36i1.10926Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 97-107, 2012 

Dependence of structural, electrical, and optical properties of ZnO:Al films on substrate temperature

2001 ◽  
Vol 16 (7) ◽  
pp. 2118-2123 ◽  
Author(s):  
M. Chen ◽  
Z. L. Pei ◽  
X. Wang ◽  
C. Sun ◽  
L. S. Wen
Keyword(s):  
Optical Properties ◽  
Carrier Concentration ◽  
Hall Mobility ◽  
Room Temperature ◽  
Fused Silica ◽  
Electrical And Optical Properties ◽  
Al Content ◽  
Visible Transmittance ◽  
Dc Magnetron Reactive Sputtering ◽  
Increasing Temperature

ZnO:Al (ZAO) films were deposited on fused silica substrates heated to 350 °C by dc magnetron reactive sputtering from a Zn target mixed with 1.5 wt% Al. Films deposited on a substrate heated to a temperature between room temperature and 300 °C were (001)-oriented crystals, but those grown at 350 °C consisted of crystallites with (001) and (101) orientations. The dependence of electrical properties such as resistivity, carrier concentration, and Hall mobility on temperature was measured. The results indicate that the carrier concentration and Hall mobility increase with increasing temperature up to 250 °C, though the Al content remains unchanged in this temperature range. The probable mechanisms are discussed. The minimum resistivity of ZAO films is 4.23 × 10−4 Ω cm, with a carrier concentration of 9.21 × 1020 cm−3 and a Hall mobility of 16.0 cm2 v−1 s−1. The films show a visible transmittance of above 80%.

THERMOELECTRIC PROPERTIES OF p-TYPE SKUTTERUDITES (Pr0.25Nd0.75)xFe3CoSb12 BY LEVITATION MELTING AND SPARK PLASMA SINTERING

2013 ◽  
Vol 06 (05) ◽  
pp. 1340006 ◽  
Author(s):  
JINGSHU XU ◽  
CHENGUANG FU ◽  
JIAN XIE ◽  
XINBING ZHAO ◽  
TIEJUN ZHU
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Levitation Melting ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

The p-type skutterudite compounds of ( Pr 0.25 Nd 0.75)x Fe 3 CoSb 12 (x = 0.67–0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr 0.25 Nd 0.75. The maximum ZT value of ~ 0.83 for ( Pr 0.25 Nd 0.75)0.76 Fe 3 CoSb 12 was obtained at 700 K.

Lattice Deformation-Induced Enhancement in Thermoelectric Properties of p-Type Bismuth Telluride-Based Alloys

2021 ◽  
Vol 13 (7) ◽  
pp. 1358-1363
Author(s):  
Min Soo Park ◽  
Gook-Hyun Ha ◽  
Yong Ho Park ◽  
Hye Young Koo
Keyword(s):  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Thermoelectric Device ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Thermal And Electrical Properties ◽  
P Type ◽  
Short Time ◽  
Sintering Method

ABSTRACTThe properties of a thermoelectric device depend on the thermoelectric material. Bi-Te-based thermoelectric materials consist of p-type and n-type semiconductors are characterized by an excellent dimensionless figure of merit (ZT). In this study, we investigated the effect of the Bi/Sb compositional ratio on the thermoelectric properties in p-type Bi–Sb–Te alloys. Bi–Sb–Te powders were prepared by melting-grinding process. The sintered bodies were fabricated by the spark plasma sintering method, which allows short time sintering for controlling the growth of particles. By controlling the Bi/Sb ratio, the carrier concentration could be optimized. An increase in the Bi concentration led to a decrease in the carrier concentration and thermal conductivity, whereas the See-beck coefficient and specific resistance were increased due to phonon scattering. The thermoelectric ZT value was found to be dependent on changes in the thermal and electrical properties. The best carrier concentration value (2.46 x 1019/cm2) and the highest ZT value (1.3) were achieved for x = 0.4 in BixSb2−xTe3.

Thermoelectric Properties of Zn4-xSb3 with x=0~0.5

2007 ◽  
Vol 124-126 ◽  
pp. 1019-1022 ◽  
Author(s):  
K.W. Jang ◽  
Il Ho Kim ◽  
Jung Il Lee ◽  
Good Sun Choi
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Hall Mobility ◽  
Room Temperature ◽  
Vacuum Melting ◽  
Increasing Temperature

Non-stoichiometric Zn4-xSb3 compounds with x=0~0.5 were prepared by vacuum melting at 1173K and annealing solidified ingots at 623K. Electrical resistivity and Seebeck coefficient at 450K increased from 1.8cm and 145K-1 for Zn4Sb3(x=0) to 56.2cm 350K-1 for Zn3.5Sb3(x=0.5) due to the decrease of the carrier concentration. Hall mobility and carrier concentration was 31.5cm2V-1s-1 and 1.32X1020cm-3 for Zn4Sb3 and 70cm2V-1s-1 and 2.80X1018cm-3 for Zn3.5Sb3. Electrical resistivity of Zn4-xSb3 with x=0~0.2 showed linearly increasing temperature dependence, whereas those of Zn4-xSb3 with x=0.3~0.5 above 450 K tended to decrease. Thermal conductivity of Zn4Sb3 was 8.5mWcm-1K-1 at room temperature and that of Zn4-xSb3 with x≥0.3 was around 11mWcm-1K-1. Maximum ZT of Zn4Sb3 was obtained around 1.3 at 600K. Zn4Sb3 with x=0.3~0.5 showed very small value of ZT=0.2~0.3.

SEEBECK COEFFICIENTS OF Mn-Si MATERIALS PREPARED BY SPARK PLASMA SINTERING

2004 ◽  
Vol 18 (16) ◽  
pp. 2279-2286 ◽  
Author(s):  
ZHI MIN WANG ◽  
YI DONG WU ◽  
YUAN JIN HE
Keyword(s):  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Pure Phase ◽  
Spark Plasma ◽  
P Type

MnSi 1.73 and MnSi samples were grown by spark plasma sintering (SPS) from different Si / Mn ratio powders, at different sintering temperatures, and for different sintering times. X-ray diffraction (XRD) measurements showed samples containing MnSi and MnSi 1.73 and Si phases, depending on the initial stoichiometries. Measurements of the Seebeck coefficient revealed p-type conductance for all samples. The Seebeck coefficients of the samples with MnSi pure phase were very low (about 10 μ V/K) and changed little at the temperature range measured. The Seebeck coefficients of the samples with MnSi 1.73, MnSi and Si phases were similar to that of the sample with near-pure MnSi 1.73 phase, which were larger than those of the samples with MnSi 1.73 and MnSi phases, but a little smaller than those of the samples with MnSi 1.73 and Si phases. It seems that, for the samples with the same phases, larger ratio of the strongest intensity peak of MnSi 1.73 to [Formula: see text], MnSi 1.73 to [Formula: see text] or both lead to larger Seebeck coeffiecients.

Electrical Properties of P-Type Thermoelectric AgxBi0.5Sb1.5-xTe3 (x=0.05~0.4) Alloys Prepared by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 868-870
Author(s):  
J.L. Cui ◽  
Y.L. Yuan ◽  
B. Hu ◽  
W. Yang
Keyword(s):  
Electrical Properties ◽  
General Formula ◽  
Spark Plasma Sintering ◽  
Binary Alloy ◽  
Power Factor ◽  
Room Temperature ◽  
Plasma Sintering ◽  
Electrical Conductivities ◽  
Spark Plasma ◽  
P Type

Thermoelectric Ag-Bi-Sb-Te alloys with the general formula AgxBi0.5Sb1.5-xTe3 (x =0.05∼0.4) were prepared by spark plasma sintering and their electrical properties were examined. The alloys exhibit large electrical conductivities in the whole temperature range, which are approximate 11.0 and 3.5 times those of pseudo-binary Bi0.5Sb1.5Te3 alloy at room temperature and 558K, respectively. The highest power factor value of 1.80×10-3 (W.K-2.m-1) is obtained for the material (x = 0.1) at the temperature of 412K, being about 2.4 times that of pseudo-binary alloy Bi0.5Sb1.5Te3 at the corresponding temperature.

Microstructure and Thermoelectric Properties of P-Type Bi0.5Sb1.5Te3 Compounds Prepared by Spark Plasma Sintering

2006 ◽  
Vol 510-511 ◽  
pp. 1122-1125
Author(s):  
Won Seung Cho ◽  
Dong Choul Cho ◽  
Cheol Ho Lim ◽  
C.H. Lee ◽  
Woon Suk Hwang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Hydrogen Reduction ◽  
Sintering Temperature ◽  
Reduction Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

The microstructure and thermoelectrical properties of the 4wt% Te doped p-type Bi0.5Sb1.5Te3 compounds, fabricated by using spark plasma sintering in the temperature ranging from 250°C to 350°C, were characterized. The density of the sintered compounds was increased to 99.2% of theoretical density by carrying out the consolidation at 350oC for 2 min. The Seebeck coefficient, thermal conductivity and electrical resistivity were dependent on hydrogen reduction process and sintering temperature. The Seebeck coefficient increased with reduction process while the electrical resisitivity significantly decreased. Also, the electrical resistivity decreased and thermal conductivity increased with sintering temperature. The results suggest that the carrier density and mobility vary with reduction process and sintering temperature. The highest figure of merit of 3.5×10-3/K was obtained for the compounds spark plasma sintered at 350°C for 2 min by using the hydrogen-reduced powders.

Bi2Te3 and Bi2Te3/Nano-SiC Prepared by Mechanical Alloying and Spark Plasma Sintering

2007 ◽  
Vol 280-283 ◽  
pp. 397-400 ◽  
Author(s):  
Jing Liu ◽  
Jing Feng Li
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Mechanical Alloying ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Materials ◽  
Room Temperature ◽  
Mechanically Alloyed ◽  
Plasma Sintering ◽  
Spark Plasma

Bi2Te3-based alloys are currently best-known, technological thermoelectric materials near room temperature. In this paper, Bi2Te3 and nano-SiC dispersed Bi2Te3 were prepared by mechanical alloying followed by spark plasma sintering (SPS). Raw powders of Bi, Te and SiC were mixed and mechanically alloyed in an argon atmosphere using a planetary ball mill. The SPS temperature was 623K, and the holding time was 5 minutes. The samples were characterized by X-ray Diffraction (XRD) and Scanning electron Microscope (SEM). The thermoelectric properties: i.e. Seebeck coefficient, electrical resistivity and thermal conductivity were measured at temperatures from room temperature to 573K, followed by the evaluation of figure of merit. The results revealed that the SiC dispersion in the Bi2Te3 matrix increased Seebeck coefficient. Although the electrical resistivity was increased somewhat, the thermal conductivity was reduced by the SiC dispersion, indicating that promising thermoelectric materials with enhanced mechanical properties may be obtained in the nano-SiC dispersed Bi2Te3 composites with optimal compositions.

High Thermoelectric Performance of p-Type Bi0.5Sb1.5Te3+xTe Crystals Prepared via Gradient Freezing

2012 ◽  
Vol 621 ◽  
pp. 167-171
Author(s):  
Tao Hua Liang ◽  
Shi Qing Yang ◽  
Zhi Chen ◽  
Qing Xue Yang
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Performance ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
P Type

p-type Bi0.5Sb1.5Te3+xTe thermoelectric crystals with various percentages of Te (x = 0.00 wt.%–3.00 wt.%) excess were prepared by the gradient freeze method. By doping with different Te contents, anti-site defects, Te vacancies and hole carrier concentrations were controlled. The Seebeck coefficient, resistivity, thermal conductivity, carrier concentration, and mobility were measured. The relationships between the Te content and thermoelectric properties were investigated in detail. The results suggested that the thermoelectric figure of merit ZT of the Bi0.5Sb1.5Te3+0.09wt.% crystals was 1.36 near room temperature, the optimum carrier concentration was 1.25 × 1019 cm-3, and the mobility was 1480 cm2 V-1 S-1, respectively.

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