scholarly journals Growth without Postannealing of Monoclinic VO2 Thin Film by Atomic Layer Deposition Using VCl4 as Precursor

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 431 ◽  
Author(s):  
Wen-Jen Lee ◽  
Yong-Han Chang
Keyword(s):  
Vanadium Dioxide ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Temperature Dependent ◽  
Vanadium Compounds ◽  
Multifunctional Material ◽  
Layer Deposition ◽  
Vanadium Tetrachloride ◽  
First Time ◽  
Deposited Films

Vanadium dioxide (VO2) is a multifunctional material with semiconductor-to-metal transition (SMT) property. Organic vanadium compounds are usually employed as ALD precursors to grow VO2 films. However, the as-deposited films are reported to have amorphous structure with no significant SMT property, therefore a postannealing process is necessary for converting the amorphous VO2 to crystalline VO2. In this study, an inorganic vanadium tetrachloride (VCl4) is used as an ALD precursor for the first time to grow VO2 films. The VO2 film is directly crystallized and grown on the substrate without any postannealing process. The VO2 film displays significant SMT behavior, which is verified by temperature-dependent Raman spectrometer and four-point-probing system. The results demonstrate that the VCl4 is suitably employed as a new ALD precursor to grow crystallized VO2 films. It can be reasonably imagined that the VCl4 can also be used to grow various directly crystallized vanadium oxides by controlling the ALD-process parameters.

scholarly journals Properties and Mechanism of PEALD-In2O3 Thin Films Prepared by Different Precursor Reaction Energy

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 978
Author(s):  
Ming-Jie Zhao ◽  
Zhi-Xuan Zhang ◽  
Chia-Hsun Hsu ◽  
Xiao-Ying Zhang ◽  
Wan-Yu Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Film Growth ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Reaction Energy ◽  
Film Growth Rate ◽  
In2o3 Film ◽  
Intermediate Temperature Range ◽  
Layer Deposition

Indium oxide (In2O3) film has excellent optical and electrical properties, which makes it useful for a multitude of applications. The preparation of In2O3 film via atomic layer deposition (ALD) method remains an issue as most of the available In-precursors are inactive and thermally unstable. In this work, In2O3 film was prepared by ALD using a remote O2 plasma as oxidant, which provides highly reactive oxygen radicals, and hence significantly enhancing the film growth. The substrate temperature that determines the adsorption state on the substrate and reaction energy of the precursor was investigated. At low substrate temperature (100–150 °C), the ratio of chemically adsorbed precursors is low, leading to a low growth rate and amorphous structure of the films. An amorphous-to-crystalline transition was observed at 150–200 °C. An ALD window with self-limiting reaction and a reasonable film growth rate was observed in the intermediate temperature range of 225–275 °C. At high substrate temperature (300–350 °C), the film growth rate further increases due to the decomposition of the precursors. The resulting film exhibits a rough surface which consists of coarse grains and obvious grain boundaries. The growth mode and properties of the In2O3 films prepared by plasma-enhanced ALD can be efficiently tuned by varying the substrate temperature.

scholarly journals Low Resistance TiO2/p-Si Heterojunction for Tandem Solar Cells

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2857
Author(s):  
Steponas Ašmontas ◽  
Maksimas Anbinderis ◽  
Jonas Gradauskas ◽  
Remigijus Juškėnas ◽  
Konstantinas Leinartas ◽  
...  
Keyword(s):  
Atomic Layer ◽  
Tandem Solar Cells ◽  
Si Substrates ◽  
Layer Deposition ◽  
Current Voltage ◽  
Niobium Doped ◽  
Specific Contact ◽  
Carrier Tunneling ◽  
P Type ◽  
Deposited Films

Niobium-doped titanium dioxide (Ti1−xNbxO2) films were grown on p-type Si substrates at low temperature (170 °C) using an atomic layer deposition technique. The as-deposited films were amorphous and showed low electrical conductivity. The films became electrically well-conducting and crystallized into the an anatase structure upon reductive post-deposition annealing at 600 °C in an H2 atmosphere for 30 min. It was shown that the Ti0.72Nb0.28O2/p+-Si heterojunction fabricated on low resistivity silicon (10−3 Ω cm) had linear current–voltage characteristic with a specific contact resistivity as low as 23 mΩ·cm2. As the resistance dependence on temperature revealed, the current across the Ti0.72Nb0.28O2/p+-Si heterojunction was mainly determined by the band-to-band charge carrier tunneling through the junction.

Temperature-Dependent Subsurface Growth during Atomic Layer Deposition on Polypropylene and Cellulose Fibers

Langmuir ◽  
2010 ◽  
Vol 26 (11) ◽  
pp. 8239-8244 ◽  
Author(s):  
Jesse S. Jur ◽  
Joseph C. Spagnola ◽  
Kyoungmi Lee ◽  
Bo Gong ◽  
Qing Peng ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Cellulose Fibers ◽  
Temperature Dependent ◽  
Layer Deposition

Characteristics of ZrO2/Al2O3 Bilayer Film for Gate Dielectric Applications Deposited by Atomic Layer Deposition Method

2004 ◽  
Vol 449-452 ◽  
pp. 497-500 ◽  
Author(s):  
Yang Do Kim ◽  
Jang Hee Lee ◽  
Jae Hyoung Koo ◽  
Ho Jung Chang ◽  
Hyeong Tag Jeon
Keyword(s):  
Gate Dielectric ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Flat Band ◽  
Bilayer Film ◽  
Carbon Impurities ◽  
Layer Deposition ◽  
Atomic Layer Deposition Method ◽  
Oriented Polycrystalline ◽  
The Individual

ZrO2/Al2O3 bilayer structure was investigated as one of potential replacements for SiO2 gate dielectric. Al2O3 and ZrO2 films were also examined and showed stoichiometric characteristics with negligible chlorine and carbon impurities. Al2O3 film exhibited an amorphous structure without interlayer formation while ZrO2 film showed a randomly oriented polycrystalline structure with amorphous phase of interlayer. ZrO2/Al2O3bilayer film exhibited no interfacial layer between Si substrate and Al2O3 layers. The flat band voltage and hysteresis of ZrO2/Al2O3bilayer film were 0.8 V and 150 mV, respectively, with fully reversible hysteresis. The measured leakage current of ZrO2/Al2O3bilayer film was 1.2E-6 A/cm2 with EOT value of 1.4 nm. ZrO2/Al2O3 bilayer film showed significantly enhanced gate oxide properties compared to those of the individual Al2O3 and ZrO2 films.

scholarly journals Atomic layer deposited films of Al2O3 on fluorine-doped tin oxide electrodes: stability and barrier properties

2021 ◽  
Vol 12 ◽  
pp. 24-34
Author(s):  
Hana Krýsová ◽  
Michael Neumann-Spallart ◽  
Hana Tarábková ◽  
Pavel Janda ◽  
Ladislav Kavan ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Direct Reduction ◽  
Aqueous Media ◽  
Atomic Layer ◽  
Barrier Properties ◽  
Glass Substrates ◽  
Oxide Electrodes ◽  
Redox Couples ◽  
Layer Deposition ◽  
Deposited Films

Al2O3 layers were deposited onto electrodes by atomic layer deposition. Solubility and electron-transport blocking were tested. Films deposited onto fluorine-doped tin oxide (FTO, F:SnO2/glass) substrates blocked electron transfer to redox couples (ferricyanide/ferrocyanide) in aqueous media. However, these films were rapidly dissolved in 1 M NaOH (≈100 nm/h). The dissolution was slower in 1 M H2SO4 (1 nm/h) but after 24 h the blocking behaviour was entirely lost. The optimal stability was reached at pH 7.2 where no changes were found up to 24 h and even after 168 h of exposure the changes in the blocking behaviour were still minimal. This behaviour was also observed for protection against direct reduction of FTO.

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