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Enhanced time response and temperature sensing behavior of thermistor using Zn-doped CaTiO_3 nanoparticles

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Journal of Advanced Ceramics 2018年第2期7卷 99-108页

作者： Subhanarayan SAHOO Department of electrical Engineering Adani Institute of Infrastructure Engineering

In the present study, Zn-doped CaTiO_3 nanocrystalline was synthesized to study the thermistor behavior with temperature. The X-ray powder diffraction analysis showed the formation of a single-phase orthorhombic structure at room temperature. The electrical resistance of the Zn-doped CaTiO_3 increased with increasing doping concentration and decreased at higher measuring temperature, showing a negative temperature coefficient of resistance(NTCR) behavior. Different thermistor parameters were calculated using Steinhart–Hart equations, whilst time domain analysis confirmed faster response towards applied voltage.

关键词： multiferroic X-ray diffraction (XRD) electrical properties conductivity impedance spectroscopy NTCR thermistor

On the profile of frequency dependent interface states and series resistance in Au/p-InP SBDs prepared with photolithography technique

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Science China(Physics,Mechanics & Astronomy) 2012年第9期55卷 1604-1612页

作者： KORUCU D. TURUT A. TURAN R. ALTINDALS. Department of Material Science and Engineering Faculty of EngineeringHakkari UniversityHakkari 30000Turkey Department of Physics Faculty of Arts and SciencesAtaturk UniversityErzurum 25240Turkey Department of Physics Faculty of Arts and SciencesMiddle East Technical UniversityAnkara 06531Turkey Department of Physics Faculty of Arts and SciencesGazi UniversityAnkara 06500Turkey

The frequency dependent of the forward and reverse bias capacitance-voltage （C-V） and conductance-voltage （G/w-V） charac- teristics of Au/p-InP SBDs have been investigated in the frequency range of 20 kHz-10 MHz and voltage range of-5 - 5 V at room temperature. The effects of surface states （Nss） and series resistance （R0 on C-V and G/w-V characteristics have been in- vestigated in detail. The frequency dependent Nss and Rs profiles were obtained for various applied bias voltages. The experi- mental results show that the main electrical parameters of Au/p-InP SBD such as barrier height （gOB）, the density of acceptor concentration （NA）, Nss and Rs were found strongly frequency and voltage dependent. The values of C and G/w decrease with increasing frequency due to a continuous distribution of Nss localized at the metal/semiconductor （M/S） interface. The effect of Rs on C and G is found considerably high especially at high frequencies. Therefore, the high frequencies of the values of C and G were corrected for the effect of Rs in the whole measured bias range to obtain the real diode capacitance Cc and conductance Gc using the Nicollian and Goetzberger technique. The distribution profile of Rs-V gives a peak depending on the frequency especially at low frequencies and disappears with increasing frequencies due to the existence of Nss at the M/S interface.

关键词： Au/p-lnP SBD electrical properties frequency dependence photolithography surface states series resistance

Characteristic analysis on the physical properties of nanostructured Mg-doped CdO thin films—Doping concentration effect

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Progress in Natural Science:Materials International 2015年第3期25卷 251-257页

作者： K.Usharani A.R.Balu V.S.Nagarethinam M.Suganya PG and Research Department of Physics A.V.V.M Sri Pushpam College

Highly conductive and transparent magnesium-doped cadmium oxide(CdO :Mg) thin films have been deposited on suitably cleaned glass substrates maintained at 375℃ by spray pyrolysis technique using perfume atomizer. The magnesium content in the films is varied from 0 to 8 at%in steps of 2 at%. The effect of Mg doping on the structural, morphological, optical and electrical properties of the CdO thin films has been *** the films exhibited cubic structure with a preferential orientation along the(1 1 1) plane irrespective of the Mg doping level. SEM analysis showed that the film morphology modifies from spherical shaped grains to closely packed cauliflower shaped nanostructures with Mg *** for the film coated with 2 at% Mg dopant, all the other doped films exhibited a blue shift in the optical band gap. electrical studies revealed that the Cd O:Mg film coated with 8 at% Mg dopant had a minimum resistivity of 0.0853*10～1Ω-cm.

关键词： X-ray diffraction Texture coefficient Thin films Optical band gap electrical properties

Selected aspects of dielectric behavior of plasma sprayed titanates

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Journal of Advanced Ceramics 2012年第1期1卷 50-59页

作者： Pavel CTIBOR Josef SEDLACEK Institute of Plasma Physics ASCRv.v.i.Za Slovankou 3PragueCzech Republic Department of Electrotechnology Faculty of Electrical EngineeringCzech Technical UniversityTechnicka 2PragueCzech Republic

XRD measurements were carried out on plasma sprayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last *** were tested as dielectrics and volume resistivities of the materials were also *** microscopy was used for mapping of the dielectric response of selected *** results show differences in the crystal structure between plasma sprayed coatings and feedstock powders in the case of BaTiO_(3)and MgTiO_(3)whereas CaTiO_(3)is crystalograffically identical with its *** reason can be found in larger sensitivity of BaTiO_(3)and MgTiO_(3)to the reductive conditions at plasma spraying whereas CaTiO_(3)seems to be rather inert from this *** CaTiO_(3)exhibits anomalous dielectric losses because of intrinsic conductivity.

关键词： plasma spraying dielectric properties electrical properties BaTiO3 and titanates capacitors

Overview of Graphene as Anode in Lithium-Ion Batteries

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Journal of Electronic Science and Technology 2018年第1期16卷 57-68页

作者： Ri-Peng Luo Wei-Qiang Lyu Ke-Chun Wen Wei-Dong He School of Energy Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731

Graphene, as a fabulously new-emerging carbonaceous material with an ideal two-dimensional rigid honeycomb structure, has drawn extensive attention in the field of material science due to extraordinary properties, including mechanical robustness, large specific surface area, desirable flexibility, and high electronic conductivity. In particular,as an auxiliary material of electrode materials, it has the potential to improve the performance of lithium-ion batteries. However, wide utilization of graphene in lithium-ion batteries is not implemented since tremendous challenges and issues,such as quality,quantity, and cost concerns, hinder its *** remains a debate whether graphene can act as an impetus in the evolution of lithium-ion batteries. In this review, we summarize the desirable properties, several common synthesis methods as well as applications of graphene as the anode in lithium-ion batteries, seeking to provide insightful guidelines for further development of graphene-based lithium-ion batteries.

关键词： Applications electrical properties graphene lithium-ion battery

Dielectric and impedance properties of sintered magnesium aluminum silicate glass-ceramic

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Journal of Advanced Ceramics 2013年第1期2卷 71-78页

作者： Abhijit PRASAD Amitabha BASU Department of Applied Physics Indian School of MinesDhanbad 826004India

Magnesium aluminum silicate(MgO-Al_(2)O_(3)-SiO_(2),MAS)glass-ceramic was prepared via sintering route.X-ray diffraction(XRD)analysis indicates the formation of multiphase compound with magnesium silicate fluoride and cordierite as major *** studies of the compound shows a strong frequency dispersion of permittivity in the low frequency region followed by a nearly frequency-independent behavior in the high frequency *** presence of alkali ions(K+)in MAS glass-ceramic results in higher dielectric constant and higher *** loss(tanδ)seems to be reduced at higher frequencies after reaching the instrumental saturation at 1 *** properties of the material have been studied using a complex impedance spectroscopy(CIS)technique in a wide temperature(30-500℃)and frequency(100 Hz-5 MHz)*** complex impedance plots reveal the contribution of bulk as well as grain boundary effects in *** bulk resistance,evaluated from complex impedance spectrum,has been observed to decrease with the rise in temperature,showing a typical negative temperature coefficient of resistance(NTCR)*** smaller activation energy(Ea)of the compound within moderate temperature range suggests the presence of ions(K^(+)and F^(-))and singly ionized oxygen vacancies in the conduction *** nature of variation of the electrical conductivity,and the values of activation energy of different temperature regions,suggest that the conduction process is of mixed type.

关键词： glass-ceramic conductivity dielectric properties electrical properties

Achievable hole concentration at room temperature as a function of Mg concentration for MOCVD-grown p-GaN after sufficient annealing

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Journal of Semiconductors 2024年第8期45卷 67-73页

作者： Siyi Huang Masao Ikeda Feng Zhang Minglong Zhang Jianjun Zhu Shuming Zhang Jianping Liu School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of SciencesSuzhou 215123China Key Laboratory of Nanodevices and Applications Chinese Academy of SciencesSuzhou 215123China

Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this *** annealing conditions were applied to obtain sufficient activation for p-GaN samples with different Mg doping *** concentration,resistivity and mobility were characterized by room-temperature Hall *** Mg doping concentration and the residual impurities such as H,C,O and Si were measured by secondary ion mass spectroscopy,confirming negligible compensations by the *** hole concentration,resistivity and mobility data are presented as a function of Mg concentration,and are compared with literature *** appropriate curve relating the Mg doping concentration to the hole concentration is derived using a charge neutrality equation and the ionized-acceptor-density[N-(A)^(-)](cm^(−3))dependent ionization energy of Mg acceptor was determined asE_(A)^(Mg)=184−2.66×10^(−5)×[N_(A)^(-)]1/3 meV.

关键词： p-GaN hole concentration electrical properties annealing ionization energy

Preparation and properties of(BEDT-TTF)_2Br3H_2O Salt

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Chinese Chemical Letters 1999年第2期10卷 179-182页

作者： Qi Chun ZHANG Pei Ji WU Ke Jian JIANG Rui Song DING Yan Qiao WANG Dao Ben ZHU(Organic Solid Lab, Institute of Chemistry, C. A. S., Beijing 100080) Organic Solid Lab. Institute of Chemistry C. A. S. Beijing 100080 China

Electrochemical oxidation of BEDT-TTF (bis (ethylenedithio) tetrathiafulvalene) inchloroform/carbon disulfide (3:1) in the presence of Bu4NBr as a supporting electrolyte at lowcurrent density results in the (BEDT-TTF)2Br3H2O crystal. Its composition has been established bychemical analysis (Br, C, H, S), XPS and IR. The temperature dependence of the resistance has beenstudied down to 26K at ambient pressure. This material has weakly metallic behavior above 230K,and becomes a semiconductor below this temperature. The structure of the complex is alsodescribed.

关键词： Organic conductor charge transfer complex preparation electrical properties structure

Photoelectric properties of Cu_2ZnSnS_4 thin films deposited by thermal evaporation

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Journal of Semiconductors 2012年第2期33卷 14-17页

作者：吴新坤柳伟程树英赖云锋贾宏杰 College of Physics and Information Engineering Institute of Micro-Nano Devices & Solar CellsFuzhou University

Sn/Cu/ZnS precursor were deposited by evaporation on soda lime glass at room temperature,and then polycrystalline thin films of Cu2ZnSnS4（CZTS） were produced by sulfurizing the precursors in a sulfur atmosphere at a temperature of 550℃for 3 *** CZTS thin films were characterized by X-ray diffraction,energy dispersive X-ray spectroscopy,ultraviolet-visible-near infrared spectrophotometry,the Hall effect system,and 3D optical *** experimental results show that,when the ratios of[Cu]/（[Zn]＋[Sn]） and[Zn]/[Sn]in the CZTS are 0.83 and 1.15,the CZTS thin films possess an absorption coefficient of larger than 4.0 x 104 cm-1 in the energy range 1.5-3.5 eV,and a direct band gap of about 1.47 *** carrier concentration,resistivity and mobility of the CZTS film are 6.98 x 1016 cm-3,6.96Ω-cm,and 12.9 cm2/（V-s）,respectively and the conduction type is ***,the CZTS thin films are suitable for absorption layers of solar cells.

关键词： Cu2ZnSnS4 evaporation optical properties electrical properties