共查询到19条相似文献,搜索用时 78 毫秒
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稀土氧化物掺杂对SnO2基气体传感器材料性能的影响 总被引:8,自引:0,他引:8
采用化学共沉淀法制备Y2O3、ZrO2,Er2O3和Sb2O2基气体传感器。结果表明掺杂后的材料经煅烧后,平均晶粒尺寸均小于30nm,比未经掺杂的材料小,中掺杂体系不同成分材料制备成厚膜传感器,进行了对CO气体敏感度性能测试,发现掺杂稀土氧化物的气体敏感度较纯SnO2厚膜传感器高。其中掺杂Er2O3材料性能最好。 相似文献
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掺杂对金属半导体氧化物气敏性能影响的研究 总被引:3,自引:2,他引:3
综述了金属氧化物半导体气敏元件的掺杂技术,探讨了掺杂作用的机理,列举了对最典型半导体气敏元件的掺杂以及掺杂对气敏元件灵敏度和选择性的影响作用。 相似文献
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TiO2基氧化物半导体氧敏传感器的研究开发进展 总被引:4,自引:0,他引:4
综合介绍TiO2基氧化物半导体氧敏传感器的研究发展历史和TiO2材料的特性,比较了各种氧敏机理、制备方法、传感器的氧敏特性,就制备方法-材料微观结构-氧敏性能关系中的几个重要问题,进行了深入的探讨,并对今后的研究开发与产业化,结合本课题组的研究工作,提出了几点建议。 相似文献
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The effect of an electromagnetic field, with frequencies in the 30 – 300 MHz range, on semiconductor cryogenic thermometers, eg silicon diode temperature sensors as well as silicon and germanium resistance thermometers, has been investigated at temperatures from 70 to 300 K.The changes in voltage drop or resistance versus temperature characteristics of the tested thermometers for various fixed frequencies of external electromagnetic field have been found. The frequency dependent electromagnetic field behaviour of the thermometers was studied and a resonance character of the ‘error’ ΔT has been evaluated.It has been shown that the semiconductor low temperature sensors may only be used for accurate recalibration in the presence of a well-known, low-intensity EM field at a constantly held frequency not corresponding with the maximum values of ΔT. 相似文献
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Kongping WuShulin Gu Kun TangShunming Zhu Jiandong YeRong Zhang Youdou Zheng 《Thin solid films》2011,519(8):2499-2503
Carbon impurities are usually unintentionally doped in N-doped ZnO when attempting to realize p-type conductivity by metal-organic chemical vapor deposition. Mn-N co-doping technique, which is developed to realize hole-mediated room temperature ferromagnetism in ZnO, may further enhance the carbon incorporation. In this work, two kinds of Mn-N co-doped samples, grown at low temperature (400 °C) and high temperature (600 °C), respectively, have been compared to study the influences of carbon impurities. In contrast to that found on N mono-doped ZnO, an enhanced incorporation of carbon impurities is observed in the high-temperature-grown Mn-N co-doped sample with the conductivity changed from p to n type. According to X-ray photoelectron spectroscopy measurement, the compensation effect from carbon impurities is applied to elucidate the origin of the conductivity transition. Correspondingly, superconducting quantum interference device measurement certainly shows a much smaller value of the saturation magnetization for the high-temperature-grown sample. A possible effect from carbon related complexes on magnetization is also proposed to explain the decrease of the magnetic moment from the view of weakened spin polarization induced by unintentionally incorporated carbon. This assumption is further supported by the first-principle calculation on the Mn-N co-doped ZnO system with carbon incorporation. 相似文献
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Ce-TiO2光催化剂的制备与性能研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了稀土Ce离子掺杂的纳米TiO2光催化剂(Ce-TiO2),通过XRD、FT-IR、UV-Vis、PL、Nano-sizer纳米粒度分析仪等对Ce-TiO2样品进行了表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察了不同掺杂浓度及经不同温度热处理后的Ce-TiO2样品对MB的光催化降解效果,结果表明所制备样品的晶型均为锐钛矿相和金红石相的混晶相,Ce离子的掺杂拓展了TiO2在可见光区的光谱响应范围,提高了TiO2光催化活性。当pH值为1.5,Ce的掺杂量为n(Ce)∶n(TiO2)=1∶300,热处理温度为600℃条件下制备的样品其催化活性显著高于Degussa P25。 相似文献
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Pr-TiO2光催化剂的制备与性能研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了稀土元素Pr掺杂的纳米TiO2光催化剂(Pr-TiO2)。通过XRD、FT-IR、UV-Vis、TEM等对Pr-TiO2样品进行了表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察了不同热处理温度及不同掺杂量的Pr-TiO2对MB的光催化降解效果。结果表明,Pr掺杂纳米TiO2的晶型为锐钛矿相和金红石相的混晶相,Pr的掺入提高了TiO2光催化活性。当热处理温度为500℃,在pH值为2.5,Pr掺杂量为n(Pr):n(TiO2)=1:300的条件下制备的光催化剂的催化活性显著高于DegussaP25。 相似文献
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We report the results of investigation of the interaction of silver with presynthesized ZnS nanoparticles (NPs) that was stabilized
by cetyl trimethyl ammonium bromide (CTAB). The photoluminescence properties of ZnS NPs were followed in the presence of Ag+ ions, Ag NPs and by the synthesis of Ag@ZnS core-shell nanoparticles. We observed that CTAB stabilized ZnS NPs emitted broadly
in the region from 350–450 nm, when excited by 309 nm light. In the presence of Ag+ ions the emission peak intensity up to 400 nm was reduced, while two new and stronger peaks at 430 nm and 550 nm appeared.
Similar results were obtained when Ag NPs solution was added to ZnS solution. However, when Ag@ZnS NPs were synthesized, the
emission in the 350–450 nm region was much weaker in comparison to that at 540 nm, which itself appeared at a wavelength shorter
than that of Ag+ ion added ZnS NPs. The observations have been explained by the presence of interstitial sulfur and Zn2+, especially near the surface of the nanocrystals and their interaction with various forms of silver. In addition, our observations
suggest that Ag+ ions diffuse into the lattice of the preformed ZnS NPs just like the formation of Ag+ doped ZnS NPs and thus changes the emission characteristics. We also have pursued similar experiments with addition of Mn2+ ions to ZnS and observed similar results of emission characteristics of Mn2+ doped ZnS NPs. We expect that results would stimulate further research interests in the development of fluoremetric metal
ion sensors based on interaction with quantum dots. 相似文献
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Christopher S. Blackman C. Piccirillo R. Binions Ivan P. Parkin 《Thin solid films》2009,517(16):4565-4570
Atmospheric pressure chemical vapour deposition of VCl4, WCl6 and water at 550 °C lead to the production of high quality tungsten doped vanadium dioxide thin films. Careful control of the gas phase precursors allowed for tungsten doping up to 8 at.%. The transition temperature of the thermochromic switch was tunable in the range 55 °C to − 23 °C. The films were analysed using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Their optical properties were examined using variable-temperature transmission and reflectance spectroscopy. It was found that incorporation of tungsten into the films led to an improvement in the colour from yellow/brown to green/blue depending on the level of tungsten incorporation. The films were optimized for optical transmission, thermochromic switching temperature, magnitude of the switching behaviour and colour to produce films that are suitable for use as an energy saving environmental glass product. 相似文献