Carrier Modulation in Bi2Te3-Based Alloys via Interfacial Doping with Atomic Layer Deposition

The carrier concentration in Bi2Te3-based alloys is a decisive factor in determining their thermoelectric performance. Herein, we propose a novel approach to modulate the carrier concentration via the encapsulation of the alloy precursor powders. Atomic layer deposition (ALD) of ZnO and SnO2 was performed over the Bi2Te2.7Se0.3 powders. After spark plasma sintering at 500 °C for 20 min, the carrier concentration in the ZnO-coated samples decreased, while the carrier concentration in the SnO2-coated samples increased. This trend was more pronounced as the number of ALD cycles increased. This was attributed to the intermixing of the metal ions at the interface. Zn2+ substituted for Bi3+ at the interface acted as an acceptor, while Sn4+ substituted for Bi3+ acted as a donor. This indicates that the carrier concentration can be adjusted depending on the materials deposited with ALD. The use of fine powders changes the carrier concentration more strongly, because the quantity of material deposited increases with the effective surface area. Therefore, the proposed approach would provide opportunities to precisely optimize the carrier concentration for high thermoelectric performance.

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Effect of Oxygen Source on the Various Properties of SnO2 Thin Films Deposited by Plasma-Enhanced Atomic Layer Deposition

Coatings ◽

10.3390/coatings10070692 ◽

2020 ◽

Vol 10 (7) ◽

pp. 692

Author(s):

Jong Hyeon Won ◽

Seong Ho Han ◽

Bo Keun Park ◽

Taek-Mo Chung ◽

Jeong Hwan Han

Keyword(s):

Electrical Properties ◽

Atomic Layer Deposition ◽

Carrier Concentration ◽

High Mobility ◽

Impurity Scattering ◽

Atomic Layer ◽

Growth Behavior ◽

Layer Deposition ◽

Growth Feature ◽

O2 Plasma

Herein, we performed a comparative study of plasma-enhanced atomic layer deposition (PEALD) of SnO2 films using Sn(dmamp)2 as the Sn source and either H2O plasma or O2 plasma as the oxygen source in a wide temperature range of 100–300 °C. Since the type of oxygen source employed in PEALD determines the growth behavior and resultant film properties, we investigated the growth feature of both SnO2 PEALD processes and the various chemical, structural, morphological, optical, and electrical properties of SnO2 films, depending on the oxygen source. SnO2 films from Sn(dmamp)2/H2O plasma (SH-SnO2) and Sn(dmamp)2/O2 plasma (SO-SnO2) showed self-limiting atomic layer deposition (ALD) growth behavior with growth rates of ~0.21 and 0.07–0.13 nm/cycle, respectively. SO-SnO2 films showed relatively larger grain structures than SH-SnO2 films at all temperatures. Interestingly, SH-SnO2 films grown at high temperatures of 250 and 300 °C presented porous rod-shaped surface morphology. SO-SnO2 films showed good electrical properties, such as high mobility up to 27 cm2 V−1·s−1 and high carrier concentration of ~1019 cm−3, whereas SH-SnO2 films exhibited poor Hall mobility of 0.3–1.4 cm2 V−1·s−1 and moderate carrier concentration of 1 × 1017–30 × 1017 cm−3. This may be attributed to the significant grain boundary and hydrogen impurity scattering.

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Effect of ZnO and SnO2 Nanolayers at Grain Boundaries on Thermoelectric Properties of Polycrystalline Skutterudites

Nanomaterials ◽

10.3390/nano10112270 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2270

Author(s):

Sang-il Kim ◽

Jiwoo An ◽

Woo-Jae Lee ◽

Se Kwon ◽

Woo Nam ◽

...

Keyword(s):

Thermal Conductivity ◽

Atomic Layer Deposition ◽

Grain Boundaries ◽

Thermoelectric Properties ◽

Phonon Scattering ◽

Atomic Layer ◽

Deposition Method ◽

Plasma Sintering ◽

Layer Deposition ◽

Atomic Layer Deposition Method

Nanostructuring is considered one of the key approaches to achieve highly efficient thermoelectric alloys by reducing thermal conductivity. In this study, we investigated the effect of oxide (ZnO and SnO2) nanolayers at the grain boundaries of polycrystalline In0.2Yb0.1Co4Sb12 skutterudites on their electrical and thermal transport properties. Skutterudite powders with oxide nanolayers were prepared by atomic layer deposition method, and the number of deposition cycles was varied to control the coating thickness. The coated powders were consolidated by spark plasma sintering. With increasing number of deposition cycle, the electrical conductivity gradually decreased, while the Seebeck coefficient changed insignificantly; this indicates that the carrier mobility decreased due to the oxide nanolayers. In contrast, the lattice thermal conductivity increased with an increase in the number of deposition cycles, demonstrating the reduction in phonon scattering by grain boundaries owing to the oxide nanolayers. Thus, we could easily control the thermoelectric properties of skutterudite materials through adjusting the oxide nanolayer by atomic layer deposition method.

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A novel approach for fabrication of bismuth-silicon dioxide core-shell structures by atomic layer deposition

Journal of Materials Chemistry ◽

10.1039/b908615c ◽

2009 ◽

Vol 19 (38) ◽

pp. 7050 ◽

Cited By ~ 22

Author(s):

Jongmin Lee ◽

Shadyar Farhangfar ◽

Renbin Yang ◽

Roland Scholz ◽

Marin Alexe ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Silicon Dioxide ◽

Atomic Layer ◽

Shell Structures ◽

Core Shell ◽

Novel Approach ◽

Layer Deposition

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Tuning the Band Gap and Carrier Concentration of Titania Films Grown by Spatial Atomic Layer Deposition: A Precursor Comparison

Nanoscale Advances ◽

10.1039/d1na00563d ◽

2021 ◽

Author(s):

Claire Armstrong ◽

Louis-Vincent Delumeau ◽

David Muñoz-Rojas ◽

Ahmed Kursumovic ◽

Judith MacManus-Driscoll ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Band Gap ◽

Carrier Concentration ◽

Atomic Layer ◽

Deposition Rates ◽

Layer Deposition ◽

Excellent Control ◽

Titania Films ◽

Free Films

Spatial atomic layer deposition retains the advantages of conventional atomic layer deposition: conformal, pinhole-free films and excellent control over thickness. Additionally, it allows higher deposition rates and is well-adapted to...

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A novel approach to black titania fabrication via atomic layer deposition for energy storage

2018 IEEE Micro Electro Mechanical Systems (MEMS) ◽

10.1109/memsys.2018.8346604 ◽

2018 ◽

Author(s):

Emmeline Kao ◽

Hyun Sung Park ◽

Xining Zang ◽

Liwei Lin

Keyword(s):

Energy Storage ◽

Atomic Layer Deposition ◽

Atomic Layer ◽

Novel Approach ◽

Layer Deposition

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Improvements of Superconducting Properties on Bi-2212 Bulks by Element Doping

Materials Science Forum ◽

10.4028/www.scientific.net/msf.787.448 ◽

2014 ◽

Vol 787 ◽

pp. 448-453 ◽

Cited By ~ 2

Author(s):

Sheng Nan Zhang ◽

Cheng Shan Li ◽

Qing Bin Hao ◽

Tian Ni Lu ◽

Ping Xiang Zhang

Keyword(s):

Carrier Concentration ◽

Precipitation Process ◽

Sintering Process ◽

Al Content ◽

Plasma Sintering ◽

Element Doping ◽

Spark Plasma ◽

Co Precipitation ◽

Precursor Powders ◽

Pinning Properties

Bi-2212 bulks have been fabricated by spark plasma sintering technique with the Bi-2212 precursor powders synthesized by co-precipitation process. The Al2O3dopants were added into the precursor powders during the sintering process. The lattice parameters of Bi-2212 increased with Al content, suggesting that Al3+ions entering into the lattice as interstitial ions due to the small ion radii. The carrier concentration has been calculated with measured room temperature thermopower values. The change of carrier concentration can be attributed to the changes of both Al and oxygen contents in the lattice. Therefore, by Al doping the samples have been tuned into optimal doping region with maximum critical temperature of 86K. The appearance of Al interstitial ions in the lattice caused certain amount of point defects, which acted as pinning centers. Therefore the flux pinning properties have been enhanced in the bulks, and obvious improvements of critical current density for over 55% have been obtained at 4.2K self-field.

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Ligand-induced reduction concerted with coating by atomic layer deposition on the example of TiO2-coated magnetite nanoparticles

Chemical Science ◽

10.1039/c8sc04474k ◽

2019 ◽

Vol 10 (7) ◽

pp. 2171-2178 ◽

Cited By ~ 5

Author(s):

Sarai García-García ◽

Alberto López-Ortega ◽

Yongping Zheng ◽

Yifan Nie ◽

Kyeongjae Cho ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Magnetite Nanoparticles ◽

Atomic Layer ◽

Core Shell ◽

Shell Nanoparticles ◽

Metal Source ◽

Novel Approach ◽

Layer Deposition ◽

Core Shell Nanoparticles

An appropriate atomic layer deposition precursor, as a function of the ligand of the metal source, can unveil a novel approach to concertedly coat and reduce γ-Fe2O3 nanoparticles to form Fe3O4/TiO2 core/shell nanoparticles.

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Investigation of the effects of interface carrier concentration on ZnO thin film transistors fabricated by atomic layer deposition

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/42/23/235102 ◽

2009 ◽

Vol 42 (23) ◽

pp. 235102 ◽

Cited By ~ 37

Author(s):

Seokhwan Bang ◽

Seungjun Lee ◽

Joohyun Park ◽

Soyeon Park ◽

Wooho Jeong ◽

...

Keyword(s):

Thin Film ◽

Atomic Layer Deposition ◽

Carrier Concentration ◽

Thin Film Transistors ◽

Atomic Layer ◽

Zno Thin Film ◽

Layer Deposition

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Titania Nanotubes/Hydroxyapatite Nanocomposites Produced with the Use of the Atomic Layer Deposition Technique: Estimation of Bioactivity and Nanomechanical Properties

Nanomaterials ◽

10.3390/nano9010123 ◽

2019 ◽

Vol 9 (1) ◽

pp. 123 ◽

Cited By ~ 9

Author(s):

Aleksandra Radtke ◽

Michalina Ehlert ◽

Tomasz Jędrzejewski ◽

Beata Sadowska ◽

Marzena Więckowska-Szakiel ◽

...

Keyword(s):

Titanium Alloy ◽

Atomic Layer Deposition ◽

Bacterial Colonization ◽

Atomic Layer ◽

Biomechanical Properties ◽

Titania Nanotubes ◽

Implant Surface ◽

Novel Approach ◽

Layer Deposition ◽

Number Of Cycles

Titanium dioxide nanotubes/hydroxyapatite nanocomposites were produced on a titanium alloy (Ti6Al4V/TNT/HA) and studied as a biocompatible coating for an implant surface modification. As a novel approach for this type of nanocomposite fabrication, the atomic layer deposition (ALD) method with an extremely low number of cycles was used to enrich titania nanotubes (TNT) with a very thin hydroxyapatite coating. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for determination of the structure and the surface morphology of the fabricated nanocoatings. The biointegration activity of the layers was estimated based on fibroblasts’ proliferation on the TNT/HA surface. The antibacterial activity was determined by analyzing the ability of the layers to inhibit bacterial colonization and biofilm formation. Mechanical properties of the Ti6Al4V/TNT/HA samples were estimated by measuring the hardness, Young’s module, and susceptibility to scratching. The results revealed that the nanoporous titanium alloy coatings enriched with a very thin hydroxyapatite layer may be a promising way to achieve the desired balance between biofunctional and biomechanical properties of modern implants.

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