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Abstract: |
Transparant conducting oxides showing the combination of high electrical conductivity and high transparency for visible light have been based on electron doping into a conduction band. For p-type delafossite oxides,the valence band is commonly the oxygen 2p band. Doping to produce holes in this band but the electronic conductivity of such p-type oxides is highly activated and can generally only be measured at temperatures well above room temperature. So it is very desirable to improve conductivity by doping wide-gap delafossites as transparant conducting oxides nowadays. The article reported the prepration and characterization of Ca-doped CuCrO2 monophasic delafossites. It was found that conductivity had a notable improvement after Ca-doped and reached 3. 2×10-2 S/cm for x=0.06 Ca-doped at room temperature and the structures had not been changed. The temperature dependence of electrical conductivity around room temperture was consistent with thermal activation type very well from 200 K to 300 K. The activation energe was 0. 36 eV before doping,but it changed to 0.27 eV when Ca-doped. This phenomenon suggest that in pure non-doped CuCrO2,carrier was the Cu+ d. After Ca-doped,the Cu2+ was formed from the Cu+ by a charge compensating process when the divalent Ca2+ substituted for the trivalent Cr3+ . The Seebeck coefficients being large positive constants implied that all the samples were p-type conducting oxides. |
Key words: Ca-doped CuCrO2,Delafossite,p-type conducting oxides |
FundProject: |
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p型透明导电氧化物CuCr1-xCaxO2的制备与光电性质研究 |
黄华,朱长飞*,刘卫
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摘要: |
系统报道了铜铁矿CuCr1-xCaxO2单相多晶材料的制备和光电性质研究结果、X光衍射(XRD)以及电导的测量. 结果表明,适当的Ca2+取代Cr3+不改变材料的晶体结构,但能显著提高材料的导电性能,x=0.06 的原始Ca2+掺杂样品在室温的电导率达到3. 2×10-2 S/cm,几乎比不掺杂样品的电导率提高了近3个数量级. 所有掺杂样品的电导率随温度的变化曲线在200~300 K,很好地符合Arrhenius 关系,其Seebeck常数均为很大的正数,这表明所有样品均为典型的p型半导体,其热激活能为0.27~0.36 eV. |
关键词: Ca掺杂CuCrO2 铜铁矿 p型导电氧化物 |
DOI:10.1088/1674-0068/17/2/161-164 |
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