Electrical conductivity and carrier concentration control in β-Ga2O3 by Si doping

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but decreases by increasing Cu concentration.

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Carrier Concentration Saturation of Double Si Doping Layers in GaAs

Japanese Journal of Applied Physics ◽

10.1143/jjap.35.l1151 ◽

1996 ◽

Vol 35 (Part 2, No. 9B) ◽

pp. L1151-L1154 ◽

Cited By ~ 2

Author(s):

Zhongling Peng ◽

Yoshiji Horikoshi

Keyword(s):

Carrier Concentration ◽

Si Doping

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Thermoelectric Properties of n-type (Bi2Se3)x(Bi2Te3)1-x Crystals Prepared by Zone Melting

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.547 ◽

2008 ◽

Vol 368-372 ◽

pp. 547-549

Author(s):

Jun Jiang ◽

Ya Li Li ◽

Gao Jie Xu ◽

Ping Cui ◽

Li Dong Chen

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Zone Melting ◽

Chemical Compositions ◽

Melting Method ◽

Temperature Range

In the present study, n-type (Bi2Se3)x(Bi2Te3)1-x crystals with various chemical compositions were fabricated by the zone melting method. Thermoelectric properties, including Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ), were measured in the temperature range of 300-500 K. The influence of the variations of Bi2Te3 and Bi2Se3 content on thermoelectric properties was studied. The increase of Bi2Se3 content (x) caused an increase in carrier concentration and thus an increase of σ and a decrease of α. The maximum figure of merit (ZT = α2σT/κ) of 0.87 was obtained at about 325 K for the composition of 93%Bi2Te3-7%Bi2Se3 with doping TeI4.

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Influence of Carbon Concentration as Coating on Electrical Conductivity of LiFeSi0.03P0.97O4/C

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1028.185 ◽

2021 ◽

Vol 1028 ◽

pp. 185-190

Author(s):

Hafizhah Ellora Della ◽

Mochamad Zainuri ◽

Pelangi Az Zahra ◽

Puri Olyvia Swastika ◽

Triwikantoro

Keyword(s):

Electrical Conductivity ◽

Carbon Concentration ◽

Research Study ◽

Raw Materials ◽

Carbon Sources ◽

Xrd Analysis ◽

Si Doping ◽

Diffraction Peaks ◽

Materials Used ◽

Carbon Concentrations

This research study about the influence of carbon concenttration as coating on electrical conductivity of LiFeSi0.03P0.97O4/C. Synthesis of LiFeSi0.03P0.97O4/C was carried out different carbon concentrations of 7, 9, and 11 wt%. The raw materials used are Fe2O3, Li2CO3, (NH4)2HPO4, SiO2 as ion Si doping, and glucose as carbon sources. The XRD analysis results showed that all the diffraction peaks in samples were the olivine LiFePO4 phase. From the EIS result, Samples with the addition carbon concentration of 9 wt% produce the highest electrical conductivity values of 4.18 x 10-7 S/cm.

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Electrical Transport and Thermoelectric Properties of SnSe–SnTe Solid Solution

Materials ◽

10.3390/ma12233854 ◽

2019 ◽

Vol 12 (23) ◽

pp. 3854 ◽

Cited By ~ 4

Author(s):

Jun-Young Cho ◽

Muhammad Siyar ◽

Woo Chan Jin ◽

Euyheon Hwang ◽

Seung-Hwan Bae ◽

...

Keyword(s):

Thermal Conductivity ◽

Solid Solution ◽

Electrical Conductivity ◽

Single Crystal ◽

Carrier Concentration ◽

Electrical Transport ◽

Lattice Thermal Conductivity ◽

Phonon Scattering ◽

Practical Applications ◽

Defect Sites

SnSe is considered as a promising thermoelectric (TE) material since the discovery of the record figure of merit (ZT) of 2.6 at 926 K in single crystal SnSe. It is, however, difficult to use single crystal SnSe for practical applications due to the poor mechanical properties and the difficulty and cost of fabricating a single crystal. It is highly desirable to improve the properties of polycrystalline SnSe whose TE properties are still not near to that of single crystal SnSe. In this study, in order to control the TE properties of polycrystalline SnSe, polycrystalline SnSe–SnTe solid solutions were fabricated, and the effect of the solid solution on the electrical transport and TE properties was investigated. The SnSe1−xTex samples were fabricated using mechanical alloying and spark plasma sintering. X-ray diffraction (XRD) analyses revealed that the solubility limit of Te in SnSe1−xTex is somewhere between x = 0.3 and 0.5. With increasing Te content, the electrical conductivity was increased due to the increase of carrier concentration, while the lattice thermal conductivity was suppressed by the increased amount of phonon scattering. The change of carrier concentration and electrical conductivity is explained using the measured band gap energy and the calculated band structure. The change of thermal conductivity is explained using the change of lattice thermal conductivity from the increased amount of phonon scattering at the point defect sites. A ZT of ~0.78 was obtained at 823 K from SnSe0.7Te0.3, which is an ~11% improvement compared to that of SnSe.

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Electrical Properties of Cubic InN And GaN Epitaxial Layers as a Function of Temperature

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300004300 ◽

2000 ◽

Vol 5 (S1) ◽

pp. 216-222

Author(s):

J.R.L. Fernandez ◽

V.A. Chitta ◽

E. Abramof ◽

A. Ferreira da Silva ◽

J.R. Leite ◽

...

Keyword(s):

Activation Energy ◽

Electrical Properties ◽

Carrier Concentration ◽

Doping Level ◽

Type Conductivity ◽

Si Doping ◽

Donor And Acceptor ◽

Cubic Gan ◽

Si Doped ◽

P Type

Carrier concentration and mobility were measured for intrinsic cubic InN and GaN, and for Si-doped cubic GaN as a function of temperature. Metallic n-type conductivity was found for the InN, while background p-type conductivity was observed for the intrinsic GaN layer. Doping the cubic GaN with Si two regimes were observed. For low Si-doping concentrations, the samples remain p-type. Increasing the Si-doping level, the background acceptors are compensated and the samples became highly degenerated n-type. From the carrier concentration dependence on temperature, the activation energy of the donor and acceptor levels was determined. Attempts were made to determine the scattering mechanisms responsible for the behavior of the mobility as a function of temperature.

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Thermoelectric properties of polycrystalline Bi2Se3−x by powder compaction sintering

Modern Physics Letters B ◽

10.1142/s0217984920502061 ◽

2020 ◽

Vol 34 (18) ◽

pp. 2050206

Author(s):

Ying Zhou ◽

Zhenhua Ge ◽

Jun Guo ◽

Jing Feng

Keyword(s):

Electrical Conductivity ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Electrical Transport ◽

Bulk Material ◽

Powder Compaction ◽

Electrical Transport Properties ◽

X Ray

[Formula: see text] is a [Formula: see text] compound (where Pn = Bi and Sb, Ch = Te, Se, and S), which has attracted increasing attention as a candidate for use in thermoelectric applications. Previous studies demonstrated the advantage of [Formula: see text] thermoelectric materials, despite an inferior thermoelectric performance. Herein, a series of [Formula: see text] ([Formula: see text], 0.10, 0.15, 0.20, and 0.25) thermoelectric materials were prepared by powder compaction sintering. The effects of phase structures and microstructure of the [Formula: see text] bulk material were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The thermoelectric properties, including Seebeck coefficient, electrical conductivity, and thermal conductivity, were measured systematically. The results show that carrier concentration increased with decreasing Se content, which in turn affected the electrical transport properties. Low Se contents gave larger power factor (PF) values than the pristine [Formula: see text] sample, the maximum PF value being [Formula: see text] at 320 K for [Formula: see text]. The variation in PF was attributed to the variations in electrical conductivity [Formula: see text] and Seebeck coefficient [Formula: see text] upon optimizing Se content. The [Formula: see text] samples showed an enhanced thermoelectric figure of merit (ZT) with increasing measurement temperature, due to the increased [Formula: see text] value, [Formula: see text], and decreased [Formula: see text]. The [Formula: see text] sample exhibited the highest ZT (0.28) at 575 K, while [Formula: see text] exhibited the lowest ZT (0.14) at 325 K. This indicated that tuning Se content was an effective way to enhance carrier concentration.

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Electrical Conduction Mechanism of Highly Transparent and Conductive ZnO Thin Films

MRS Proceedings ◽

10.1557/proc-666-f1.3 ◽

2001 ◽

Vol 666 ◽

Cited By ~ 42

Author(s):

Tadatsugu Minami ◽

Shingo Suzuki ◽

Toshihiro Miyata

Keyword(s):

Electrical Conductivity ◽

Carrier Concentration ◽

Conduction Band ◽

Conduction Mechanism ◽

Impurity Scattering ◽

Zno Thin Films ◽

Zno Films ◽

Boundary Scattering ◽

Ionized Impurity Scattering ◽

Transparent Conducting

ABSTRACTIn this paper, we describe the underlying theory along with experiments concerning the electrical conductivity of transparent conducting ZnO films with a carrier concentration of 1019-1021 cm−3. The experimentally determined mobility as a function of carrier concentration in the range of 1019-1021 cm−3 could be quantitatively referenced to a theoretically calculated mobility that is dominated by not only grain boundary scattering but also ionized impurity scattering using the Brooks-Herring-Dingle theory with both degeneracy and nonparabolicity of the conduction band taken into account. Concerning nonparabolicity, the conduction band effective mass as a function of carrier concentration was theoretically analyzed and experimentally determined.

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Efficient interlayer charge release for high-performance layered thermoelectrics

National Science Review ◽

10.1093/nsr/nwaa085 ◽

2020 ◽

Cited By ~ 3

Author(s):

Hao Zhu ◽

Zhou Li ◽

Chenxi Zhao ◽

Xingxing Li ◽

Jinlong Yang ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

High Performance ◽

Lattice Thermal Conductivity ◽

Transport Barrier ◽

High Seebeck Coefficient ◽

Valence Bands ◽

Increase Carrier Concentration

Abstract Many layered superlattice materials intrinsically possess large Seebeck coefficient and low lattice thermal conductivity, but poor electrical conductivity because of the interlayer transport barrier for charges, which has become a stumbling block for achieving high thermoelectric performance. Herein, taking BiCuSeO superlattice as an example, it is demonstrated that efficient interlayer charge release can increase carrier concentration, thereby activating multiple Fermi pockets through Bi/Cu dual vacancies and Pb codoping. Experimental results reveal that the extrinsic charges, which are introduced by Pb and initially trapped in the charge-reservoir [Bi2O2]2+ sublayers, are effectively released into [Cu2Se2]2− sublayers via the channels bridged by Bi/Cu dual vacancies. This efficient interlayer charge release endows dual-vacancy- and Pb-codoped BiCuSeO with increased carrier concentration and electrical conductivity. Moreover, with increasing carrier concentration, the Fermi level is pushed down, activating multiple converged valence bands, which helps to maintain a relatively high Seebeck coefficient and yield an enhanced power factor. As a result, a high ZT value of ∼1.4 is achieved at 823 K in codoped Bi0.90Pb0.06Cu0.96SeO, which is superior to that of pristine BiCuSeO and solely doped samples. The present findings provide prospective insights into the exploration of high-performance thermoelectric materials and the underlying transport physics.

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