Preliminary comparison of three processes of AlN oxidation: dry, wet and mixed ones

Korbutowicz, R.; Zakrzewski, A.

doi:10.1515/msp-2016-0010

Cited by 4 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The origin of the air stability can begin to be understood by considering if the n ‐type doped states will participate in the reduction of water or the oxidation of wet oxygen 36,55,56. If the pH of the surrounding environment is 7 with negligible over potentials, the doped n ‐type organic material is stable toward reduction of water when the work function is located between 3.7 and 5.0 eV.…”

Section: Resultsmentioning

confidence: 99%

“…The origin of the air stability can begin to be understood by considering if the n-type doped states will participate in the reduction of water or the oxidation of wet oxygen. [36,55,56] If the pH of the surrounding environment is 7 with negligible over potentials, the doped n-type organic material is stable toward reduction of water when the work function is located between 3.7 and 5.0 eV. When the work function is located deeper than 5.0 eV, doped n-type organic materials will be further reduced by water with oxygen, but this should not be a problem since it corresponds to further electron doping.…”

Section: Air Stabilitymentioning

confidence: 99%

See 1 more Smart Citation

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])

Hwang

Potscavage

Kim

et al. 2020

Adv Elect Materials

View full text Add to dashboard Cite

Recent progress in organic thermoelectric generators has resulted in high performance through chemical control of the redox levels of organic semiconductors, but the scarcity of good candidates for soluble organic n‐type materials limits the use of π‐leg structures consisting of complementary elements of p‐ and n‐type materials because of unbalanced transport coefficients that lead to power losses. A sol–gel technique with oxidation is demonstrated to be effective for the fabrication of smooth films of poly(nickel 1,1,2,2‐ethenetetrathiolate), P(MX[Niett]), which is known as an insoluble material. By controlling the annealing temperature, a maximum n‐type power factor of 10.1 μW m−1 K−2 at 100 °C (Seebeck coefficient of −35.4 μV K−1 and electrical conductivity of 80.3 S cm−1) is demonstrated. Chemical and electronic structures of P(MX[Niett]) thin films are explored based on changes in optical absorption, ultraviolet, and X‐ray photoelectron spectroscopies to understand the origin of the high atmospheric stability. Analysis indicates that the stability arises from electronic states of the doped state that satisfy a balance with the redox potential of the air components and that stability under repeated redox reactions is an important factor for obtaining the n‐type organic thermoelectric materials that are highly stable in air.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Air Stabilitymentioning

confidence: 99%

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])

Hwang

Potscavage

Kim

et al. 2020

Adv Elect Materials

View full text Add to dashboard Cite

show abstract

“…Aluminum nitride coating, deposited by chemical vapor deposition at 1373 K was selected for its high thermal conductivity, low thermal expansion coefficient, high temperature stability and its ability to develop stable alumina scales at high temperature [11]. Al2O3 layer which is formed during high temperature air exposure can modify underlying substrate properties [12][13][14][15] [11,[16][17]. Along with low fabrication costs, these coatings also present self-healing effects if the protective surface oxide layer fails [18].…”

Section: Introductionmentioning

confidence: 99%

High temperature properties of AlN coatings deposited by chemical vapor deposition for solar central receivers

Chen

Colas

Mercier

et al. 2019

Surface and Coatings Technology

View full text Add to dashboard Cite

There is an increasing interest for tower concentrated solar power (CSP) systems which can work at temperatures higher than 1073 K to optimize the efficiency. One of the challenges is to design the receiver that will be heated at high temperatures. On the contrary to coatings in gas turbine engine, the coating/substrate system must have a high thermal conductivity to ensure a good heat transfer to the fluid. Aluminum nitride (AlN) coating, deposited by chemical vapor deposition at 1373 K at a growth rate of 10-50 µm h-1 , was selected for its high thermal conductivity, low thermal expansion coefficient, high temperature stability and its ability to develop stable alumina scales above 1273 K. Cast and ODS (Oxide Dispersion Strengthened) FeCrAl alloys, also alumina-formers, were chosen as model substrates to reduce the influencing parameters in real-life receivers and to study the potential of these coatings. Accelerated cyclic oxidation tests and emissivity measurements allowed the evaluation of AlN coatings as materials for high temperature CSP receivers. The multilayered systems showed low degradation after hundreds of thermal cycles at 1073 K in air and can support higher temperatures (1373 K) for 100 to 500 h depending on the coating thickness. Nevertheless the fast cyclic oxidations in solar furnace generated cracks through the coatings. The measurement of the optical properties also revealed a decrease of the absorptivity after oxidation.

show abstract

“…Therefore, the oxidation of AlN ceramics remains the major challenges for its practical applications. Numerous efforts have been made to investigate the oxidation of AlN with aid of a series of experimental observations. − The oxidation of AlN ceramics under two different oxidizing atmospheres was studied by Hou et al, which indicates that the oxidation rate of AlN strongly depends on temperature and oxygen partial pressure. It is widely believed that the main oxidation products of AlN are Al 2 O 3 and N 2 . , The formation and escape of N 2 lead to produce a porous oxide layer on the surface of AlN, which promotes the infiltration of oxygen molecules.…”

Section: Introductionmentioning

confidence: 99%

Wurtzite AlN(0001) Surface Oxidation: Hints from Ab Initio Calculations

Zhi¹,

Wang²,

Chen³

et al. 2018

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

With superior electrical and thermal properties, aluminum nitride (AlN) exhibits wide application. However, AlN is rather oxygen-sensitive and tends to be oxidized at high temperature. The surface oxidation of AlN remains a major challenge, while the underlying physics of AlN surface oxidation is still elusive. Here, First-principles calculations were performed to study wurtzite AlN(0001) surface oxidation process. The adsorption energy of oxygen was calculated to be site-dependent on the surface with varying O coverage. Calculation indicates that oxygen atoms are preferentially adsorbed at the hollow site (H3) of the AlN(0001) surface regardless of the O coverage. N is determined as the dominant gas product. The procedure of N removal and the formation of N vacancies (V) take place step by step. V plays an accelerating role in the oxidation of AlN, and O prefers to occupy the site of V via consuming the Al p lone-pair electrons and passivating the dangling bond states of Al. An O-Al-O layer is formed when the first Al-N bilayer is fully oxidized, which could be regarded as a precursor of γ-AlO. On the basis of our atomic-level simulation, a possible phase transformation mechanism from γ-AlO to α-AlO was further proposed.

show abstract

Preliminary comparison of three processes of AlN oxidation: dry, wet and mixed ones

Cited by 4 publications

References 11 publications

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])

High temperature properties of AlN coatings deposited by chemical vapor deposition for solar central receivers

Wurtzite AlN(0001) Surface Oxidation: Hints from Ab Initio Calculations

Contact Info

Product

Resources

About

Preliminary comparison of three processes of AlN oxidation: dry, wet and mixed ones

Cited by 4 publications

References 11 publications

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(NaX[Niett])

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(NaX[Niett])

High temperature properties of AlN coatings deposited by chemical vapor deposition for solar central receivers

Wurtzite AlN(0001) Surface Oxidation: Hints from Ab Initio Calculations

Contact Info

Product

Resources

About

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])

Interplay Among Thermoelectric Properties, Atmospheric Stability, and Electronic Structures in Solution‐Deposited Thin Films of P(Na_X[Niett])