Spectral assignments in the infrared absorption region and anomalous thermal hysteresis in the interband electronic transition of vanadium dioxide films

2016 ◽  
Vol 18 (8) ◽  
pp. 6239-6246 ◽  
Author(s):  
Peng Zhang ◽  
Mengjiao Li ◽  
Qinglin Deng ◽  
Jinzhong Zhang ◽  
Jiada Wu ◽  
...  
Keyword(s):  
Infrared Absorption ◽  
Vanadium Dioxide ◽  
Electronic Transition ◽  
Thermal Hysteresis ◽  
Absorption Region

The spectral slopes of transmittance and reflectance in the infrared absorption region and the interband electronic transition for VO2 have been investigated.

scholarly journals Фазовый переход полупроводник-металл и "тристабильное" электрическое переключение в нанокристаллических пленках оксида ванадия на кремнии

2019 ◽  
Vol 45 (12) ◽  
pp. 3
Author(s):  
Е.А. Тутов ◽  
Д.Л. Голощапов ◽  
В.П. Зломанов
Keyword(s):  
Phase Transition ◽  
Direct Current ◽  
Vanadium Dioxide ◽  
Complex Shape ◽  
Thermal Hysteresis ◽  
Charge Carriers ◽  
Electrical Switching ◽  
Metal Phase Transition ◽  
Consecutive Phase ◽  
First Time

Abstract. It has been found at measurements on alternating current that the loop of a thermal hysteresis of semiconductor–metal phase transition in vanadium dioxide VO2 has the asymmetrical multistage form. On a direct current the complex shape of a hysteresis loop wasn't shown. Such behavior for VO2 films can be defined by heterophase nanocrystal structure of vanadium oxide and different type of charge carriers in grains volume and surfaces. The phenomenon is connected with consecutive phase transition in groups of nanocrystallites of the close size. In such films electrical switching with the "tristate" mode for the first time is revealed.

Effects of He-irradiation on the Metal-to-insulator Transition of Vanadium Dioxide Nanoclusters

2010 ◽  
Vol 1256 ◽  
Author(s):  
Helmut Karl ◽  
Jing Peng ◽  
Bernd Stritzker
Keyword(s):  
Long Range ◽  
Vanadium Dioxide ◽  
Thermal Hysteresis ◽  
Low Frequency ◽  
Structural Disorder ◽  
Insulator Transition ◽  
Spectral Ellipsometry ◽  
Projected Range ◽  
Metal To Insulator Transition ◽  
Electronic Doping

AbstractIn this work nanoclusters of vanadium dioxide (VO2) buried in 200 nm thick SiO2 on silicon have been irradiated with increasing fluences of He ions. The projected range of He was chosen to be 650 nm in order to avoid residual He in the VO2 nanoclusters and the surrounding SiO2. The VO2 nanoclusters have been synthesized by sequential ion implantation of the elements vanadium and oxygen followed by a rapid thermal annealing step. Irradiation with He ions leads to the generation of reversible lattice point defects in the nanocrystalline VO2 precipitates. Simultaneously there is no electronic doping by He incorporation. The effect of the local- and long-range structural disorder on the metal-to-insulator phase transition has been investigated as a function of He fluence by μ-Raman spectroscopy and temperature dependent spectral ellipsometry. The disappearance of a low-frequency Raman mode indicates increasing disorder in the long-range crystal structure due to He irradiation. At the same time the thermal hysteresis of the metal-to-insulator transition narrows.

scholarly journals "The Effects of Additive TiO2 Nanoparticles on the Optical properties of DCM Doped with PVC Thin Films "

2018 ◽  
Vol 5 (1) ◽  
pp. 27-35
Author(s):  
Shymaa K. Hussian ◽  
Thill A. Kadhum Al-musaw ◽  
Shatha Raheem Helal Al himidi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Tio2 Nanoparticles ◽  
Electronic Transition ◽  
Transition Energy ◽  
Energy Gap ◽  
Sol Gel ◽  
Titania Nanoparticles ◽  
Absorption Region ◽  
Electronic Transition Energy

"In this work thin films containing laser dye (DCM) doped with (PVC) were prepared using casting method. Titania (TiO2) nanoparticles also were synthesized using sol-gel technique. Different titania nanoparticle densities (0.882×1020, 1.765×1020, 2.648×1020 and 3.530×1020 cm-3) were co-doping with dye doped polymer to study the effect of this addition on the optical properties and electronic transition energy gaps in cases of both direct and indirect transitions, Absorbance spectra were measured using Spectrophotometer. Absorption and extinction coefficients as well as the refractive indices have been obtained the spectra of absorbance at the strong absorption region. It was observed from results that the allowed direct electronic transitions energy gap was decreasing from 2.22 to 2.175e.V with the increasing of titania nanoparticles density and the allowed indirect electronic transition energy gap decreasing from 2.19 to 2.13e.V.

scholarly journals Диэлектрическая спектроскопия и особенности механизма фазового перехода полупроводник-металл в пленках VO-=SUB=-2-=/SUB=-

2020 ◽  
Vol 54 (2) ◽  
pp. 153
Author(s):  
А.В. Ильинский ◽  
Р.А. Кастро ◽  
М.Э. Пашкевич ◽  
Е.Б. Шадрин
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Vanadium Dioxide ◽  
Thermal Hysteresis ◽  
Hysteresis Loops ◽  
Electrical Circuit ◽  
Equivalent Electrical Circuit ◽  
Transition Mechanism ◽  
Metal Phase Transition ◽  
Frequency Dependences

Abstract In the range of 0.1–10^6 Hz, the temperature-induced transformation of the frequency dependences of the dielectric-loss tangent tanδ( f ) as well as the Cole–Cole diagrams for undoped vanadium-dioxide films are investigated. The measurements are carried out in the temperature range T = 273–373 K. It is shown that the shape of the Cole–Cole diagrams for all films depends slightly on the temperature in the specified interval, while the frequencies f _0 corresponding to the peaks of the function tanδ( f ) increase with temperature. The thermal-hysteresis loops of the frequency positions f _0( T ) of the peaks are measured. When interpreting the data of dielectric spectroscopy, a complex equivalent electrical circuit of the sample is used; it makes it possible to detect the presence of two types of grains with different electrical properties in undoped VO_2 films. The presence of two types of grains determines the features of the semiconductor–metal phase-transition mechanism in VO_2 films.

Spatiotemporal Modulation of Thermal Emission from Thermal-Hysteresis Vanadium Dioxide for Multiplexing Thermotronics Functionalities

2021 ◽  
Vol 38 (12) ◽  
pp. 124401
Author(s):  
Guanying Xing ◽  
Weixian Zhao ◽  
Run Hu ◽  
Xiaobing Luo
Keyword(s):  
Vanadium Dioxide ◽  
System Integration ◽  
Thermal Emission ◽  
Thermal Hysteresis ◽  
Emission Characteristics ◽  
Information Carrier ◽  
Practical Applications

Taking heat positively as the information carrier, thermotronics can exempt the long-lasting thermal issue of electronics fundamentally, yet has been faced with the challenging multiplexing integration of diverse functionalities. Here, we demonstrate a spatiotemporal modulation platform to achieve multiplexing thermotronics functionalities based on the thermal-hysteresis vanadium dioxide, including negative-differential thermal emission, thermal diode, thermal memristor, thermal transistor, and beyond. The physics behind the multiplexing thermotronics lies in the thermal hysteresis emission characteristics of the phase-changing vanadium dioxide during the spatiotemporal modulation. The present spatiotemporal modulation is expected to stimulate more exploration on novel functionalities, system integration, and practical applications of thermotronics.

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