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1.
张飞  居靖淇 《红外》2022,43(3):1-7
采用双洛伦兹模型和有效介质近似(Efficient Medium Approximation, EMA)色散模型对退火的Mn1.95Co0.77Ni0.28O4薄膜在近红外和中红外波段的椭偏数据进行了拟合。通过比较直流电压下测试的电导率与低频下计算的电导率(ω→0)发现,A谐振子主要产生传导电流,B谐振子主要产生位移电流。对于Mn1.95Co0.77Ni0.28O4薄膜,随着退火温度的升高,晶格共振吸收逐渐被电子共振吸收所取代。退火样品的折射率n和消光系数k均由退火过程决定。  相似文献   

2.
尖晶石Mn-Co-Ni-O三元氧化物具有优良的负温度系数(NTC),是一种制作热敏红外探测器较为理想的材料。采用射频磁控溅射法在非晶Al2O3衬底上制备了Mn1.56Co0.96Ni0.48O4(MCNO)多晶薄膜。使用能量色散X射线谱(EDS)对薄膜中金属元素组分进行了测量,分析得出薄膜中金属元素组分与靶材中的组分偏离在5%以内。对经过750℃空气中退火后的薄膜结构、电学和光学性质也进行了研究。实验结果表明:退火后薄膜具有单一立方尖晶石结构,且薄膜表面致密、均匀性好;薄膜的传导机制遵循小极子跃迁传导,在240~330K范围内符合VRH模型,其激活能和电阻温度系数(TCR)在室温下(300K)分别为0.297eV和-3.83%K-1;薄膜在紫外-可见波段具有较高的吸收率,间接带宽为0.61eV。  相似文献   

3.
赵媛媛  王园园  王荣新  王志鹏  朱煜  宋贺伦  向阳 《红外与激光工程》2024,54(4):20230723-1-20230723-10
红外热成像技术具有高度实用性、灵敏性和可靠性等优点,在航空、医疗等多个领域发挥着重要作用。相较于其他类型的非制冷红外探测器,测微辐射热计(Microbolometer)具有工作范围宽、响应速率快且器件结构简单等优点。相较于非晶硅和氧化钒等常见热敏层材料,立方尖晶石结构的过渡金属氧化物锰钴镍氧化物(Mn-Co-Ni-O,MCNO)具有更高的TCR系数。使用磁控溅射法-电子束蒸发复合法在蓝宝石(Al2O3)衬底上制备MCNO薄膜,结合XRD、SEM和电学性能测试,分析和探讨了工艺条件对其性能的影响。研究结果表明,在450 ℃沉积 5 h得到厚度为450 nm的MCNO薄膜样品,随后在真空腔内原位退火1 h,再使用管式退火炉在空气氛围中进行60 min 850 ℃后退火,MCNO薄膜呈现出良好性能,(111)晶相的XRD半峰宽为0.48,晶格常数为8.71 Å(1 Å=10–10 m),晶粒平均大小为81.7±24 nm。使用四探针法测试MCNO薄膜室温下电阻率为642.19 Ω·cm,室温下(295 K)电阻温度系数(Temperature Coefficient of Resistance, TCR)系数为−4.20%/K。在6~8.5 μm波长范围内,最高吸光度为1.50。研究结果验证了所提出的多层复合方法用于制备MCNO薄膜的可行性,为进一步优化MCNO薄膜组份与掺杂配比以及结构-性能关系提供了新思路。  相似文献   

4.
为了获得光电性能好的ZnS窗口层薄膜,采用电子束蒸发法在玻璃基片上沉积ZnS薄膜,研究退火温度(200~500℃)对ZnS薄膜的结构和光电性能的影响。结果表明:所制备的薄膜均为闪锌矿结构的β-ZnS多晶薄膜,导电类型为n型。随着退火温度的增高,薄膜结晶度和光电性能都变好。但是,当退火温度过高(500℃)时,薄膜的半导体特性反而变差。退火温度为400℃时,ZnS薄膜的性能最佳,此时薄膜的透过率较高;电阻率较低,为246.2?.cm。  相似文献   

5.
研究了退火处理对ZnO薄膜结晶性能的影响.ZnO薄膜由直流反应磁控溅射技术制得,并在O2气氛中不同温度(200~1000℃)下退火,利用X射线衍射(XRD)、原子力显微镜(AFM)和X射线光电子能谱(XPS)对其结晶性能进行了研究,提出了一个较为完善的ZnO薄膜退火模型.研究表明:热处理可使c轴生长的薄膜取向性增强;随退火温度的升高,薄膜沿c轴的张应力减小,压应力增加;同时晶粒度增大,表面粗糙度也随之增加.在640℃的应力松弛温度(SRT)下,ZnO薄膜具有很好的c轴取向,沿c轴的应力处于松弛状态,晶粒度不大,表面粗糙度较小,此时ZnO薄膜的结晶性能最优.  相似文献   

6.
退火处理对ZnO薄膜结晶性能的影响   总被引:30,自引:1,他引:29  
研究了退火处理对Zn O薄膜结晶性能的影响.Zn O薄膜由直流反应磁控溅射技术制得,并在O2 气氛中不同温度(2 0 0~10 0 0℃)下退火,利用X射线衍射(XRD)、原子力显微镜(AFM)和X射线光电子能谱(XPS)对其结晶性能进行了研究,提出了一个较为完善的Zn O薄膜退火模型.研究表明:热处理可使c轴生长的薄膜取向性增强;随退火温度的升高,薄膜沿c轴的张应力减小,压应力增加;同时晶粒度增大,表面粗糙度也随之增加.在6 4 0℃的应力松弛温度(SRT)下,Zn O薄膜具有很好的c轴取向,沿c轴的应力处于松弛状态,晶粒度不大,表面粗糙度较小,此时Zn O薄膜的结晶性能最优.  相似文献   

7.
采用射频磁控溅射法在Pt/Ti/LaAlO3(100)衬底上制备了BaO-Nd2O3-Sm2O3-TiO2系(BNST)薄膜.研究了退火温度对BNST薄膜结构、表面形貌和介电性能的影响.X线衍射仪(XRD)分析表明,随着退火温度的升高,晶粒逐渐长大.经850℃退火处理的BNST薄膜具有很好的结晶质量.原子力显微镜(AFM)分析表明,在一定范围内提高退火温度所制备的薄膜晶粒致密、大小均匀.LCR测试分析表明,在测试频率为100 kHz时,随着退火温度的升高,BNST薄膜介电常数有所增加,介电损耗则先降低,后增加.实验表明,经850℃退火处理,所制备的BNST薄膜的介电常数达37,介电损耗小于1.2‰.  相似文献   

8.
利用磁控溅射法在硅(Si)衬底上沉积了Ta2O5薄膜,对薄膜进行了不同温度的退火处理,并利用X射线衍射仪对薄膜的微观结构进行了分析.然后在Si的背面和介电薄膜的上面沉积Pt电极,组成了金属—氧化物—半导体( MOS)电容器,对不同温度下退火得到的薄膜制备的MOS电容器的电学性能进行了研究.结果表明,薄膜在700℃开始结...  相似文献   

9.
张飞 《红外》2020,41(9):25-30
研究了用Mn-Co-Ni-O薄膜材料制备的热敏红外探测器件,并主要通过调控衬底热导改进了器件性能.对于较薄的探测元,研究了具有微桥结构的红外器件.结果 表明,该器件的响应率比非微桥器件高80%左右,探测率高44%左右.这主要是因为其独特的结构形式降低了器件热导,且对光的全反射效应提高了探测元对光的吸收率.对于较厚的探测...  相似文献   

10.
退火对聚合物有机发光器件的影响   总被引:1,自引:2,他引:1  
制作了结构为ITO/MEH—PPV/AI的单层聚合物有机发光器件(PLED),在镀铝电极前后分别对器件进行高于MEH—PPV玻璃化温度的退火处理。结果表明,镀铝电极后的退火处理可使器件的效率提高30%左右,器件的寿命增加40%左右;而镀铝电极前的退火处理对器件影响不大。  相似文献   

11.
    
Researchers worldwide focus on new earth abundant and cheap absorber materials for use in thin film solar cells that allow wider use of photovoltaics in energy production. SnS is one of such promising absorber materials that comprises earth abundant elements (Sn, S). We describe here the effect of annealing of high vacuum evaporated (HVE) SnS thin films in vacuum and nitrogen atmosphere with relatively high pressures of nitrogen. SnS thin films with a thickness of 500 nm were deposited onto the surface of glass by HVE at a substrate temperature of 300 °C. The as-deposited SnS thin films were annealed at 500 °C and 550 °C for 1 h in vacuum as well as in nitrogen with respect to ambient (N2) pressure that varied in the range of 500–2000 mbar. We analyze crystalline quality, crystal structure, elemental and phase compositions, and electrical properties of SnS films before and after the annealing process and their changes. Our results show that the use of pressurized inert ambient, such as nitrogen, improves the crystalline quality as well as the electrical properties of SnS thin films. The enhanced growth of crystals and modification of microstructural properties of SnS thin films as a function of annealing conditions (type of ambient, annealing temperature and ambient pressure) are discussed in detail.  相似文献   

12.
The tantalum oxide thin films with a thickness of 14 nm were deposited at 95°C by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECRPECVD), and annealed at various temperatures (700∼850°C) in O2 and N2 ambients. The microstructure and composition of the tantalum oxide thin films and the growth of interfacial silicon oxide layer were investigated and were related to the electrical characteristics of the film. Annealing in an O2 ambient led to a high dielectric constant (εr(Ta2O5) = 24) as well as a small leakage current (Ebd = 2.3 MV/cm), which were due to the improved stoichiometry and the decreased impurity carbon content. Annealing in an N2 ambient resulted in poor and nonuniform leakage current characteristics. The as-deposited tantalum oxide films were crystallized into δ-Ta2O5 after annealing at above 750°C regardless of the ambient. The leakage current of the film abruptly increased after annealing at 850°C probably because of the stress caused by thermal expansion or contraction.  相似文献   

13.
采用溶胶-凝胶法在单晶硅上制备了钴铁氧体薄膜。在不同温度下对样品进行了退火处理,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和振动样品磁强计(VSM)等分析了样品的物相组成、晶粒大小、表面形貌、样品厚度及不同温度下的磁性能。结果表明:制备出的CoFe2O4薄膜为尖晶石结构,表面比较致密,平均晶粒尺寸20~50 nm。在173~400 K范围内,随着温度的升高,钴铁氧体薄膜的矫顽磁场逐步减小,而磁矩是先增加后减少,并对产生的原因进行了分析。  相似文献   

14.
    
Nanocrystalline Zn1-x CoxO(where x varies from 0 to 0.04 in steps of 0.01) thin films were deposited onto glass substrate by the spray pyrolysis technique at a substrate temperature of 350 ℃. The X-ray diffraction patterns confirm the formation of hexagonal wurtzite structure. The crystal grain size of these films was found to be in the range of 11–36 nm. The scanning electron micrographs show a highly crystalline nanostructure with different morphologies including rope-like morphology for undoped ZnO and nanowalls and semispherical morphology for Co-doped Zn O. The transmittance increases with increasing Co doping. The optical absorption edge is observed in the transmittance spectra from 530 to 692 nm, which is due to the Co2C absorption bands corresponding to intraionic d–d shifts. The direct and indirect optical band gap energies decrease from 3.05 to 2.75 eV and 3.18 to 3.00 eV, respectively for 4 mol% Co doping. The electrical conductivity increases with increasing both the Co doping and temperature, indicating the semiconducting nature of these films. The temperature dependence thermal electromotive force measurement indicates that both undoped and Co-doped ZnO thin films show p-type semiconducting behavior near room temperature. This behavior dies out beyond 313 K and they become n-type semiconductors.  相似文献   

15.
16.
Interfacial reactions between cobalt thin films and (001) GaAs have been studied by transmission electron microscopy, energy-dispersive analysis of x-rays in a scanningTEM, Auger electron spectroscopy and x-ray photoelectron spectroscopy. The completely reacted layer was found to be “β-Ga203/(CoGa, CoAs)/GaAs.” The formation of a surface layer ofβ-Ga2O3 and the use of encapsulated samples minimized As loss from the reacted layer. Both CoGa and CoAs were found to grow epitaxially on (001) GaAs. The orientation relationships between CoGa and GaAs were determined to be [001] CoGa//[001] GaAs and (220) CoGa//(220) GaAs. The Burgers vectors of interfacial dislocations were identified as 1/2 〈101〉 and 1/2 〈011〉 which are inclined to the (001) GaAs surface. Almost all of the CoGa films were found to be epitaxially related to the surface. No interfacial dislocations were observed in most of the epitaxial CoAs films which are considered to be pseudomorphic with respect to GaAs. The orientation relationships between CoAs and GaAs were determined to be [101] CoAs//[011] GaAs and (020) CoAs//(220) GaAs. Two-step annealing was found to be effective in promoting epitaxial growth.  相似文献   

17.
    
Interfacial stress present in ferroelectric thin films is known to affect largely their piezoelectric properties by modifying crystal orientation and domain structure. Here, a nonconventional way is proposed to substantially improve the polarization and piezoelectric characteristics of Pb(Zr,Ti)O3 thin films by modifying the surface of the typical Si substrate into an embossed structure with Ni nanodots. Uniform Ni nanodot arrays are successfully produced by an external magnetic field through the consolidation process of thin Ni layer. The exceptionally large thermal expansion mismatch of ≈94% between the thin films and the Ni nanodots is believed to induce a large local‐compressive stress around the nanodot region and thus the intensified orientation toward c‐axis. For this demonstration, the in situ sputtering processing enabled by combining heavily 12 mol% Nb‐doping with a bottom electrode structure of Ir/TiW is used. As a highlight of the improvement, a significant increase of ≈33% in effective piezoelectric coefficient is observed for the 90 nm Ni nanodot case. An apparent shift of the polarization–electric field curve suggests the existence of internal field, as an evidence of the in situ domain formation.  相似文献   

18.
超声共沉淀法合成锂离子电池正极材料   总被引:1,自引:1,他引:1  
采用超声共沉淀法,合成尖晶石型掺杂锰酸锂Li1.05Co0.10Ni0.10Mn1.80O4前驱体,并使用三段热处理方式,制备出尖晶石产物。用粒度分布、XRD、SEM、EDS及电化学性能测试等对其进行表征。结果表明:与未处理试样相比,超声共沉淀法制备的产物的粒度分布变窄,体积比表面积由7.0116m2/cm3缩小至6.9789m2/cm3,晶格常数从0.822nm缩小至0.821nm,晶粒尺寸从67.41nm减小至57.78nm,晶形更加完整,颗粒均匀性更好。经装配成电池测定电化学性能,其充放电平台增长,比容量加大,循环性能更优越。  相似文献   

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