文档介绍：摘要金刚石作为宽禁带半导体材料与其它材料相比,具有非常低的介电常数,很高的禁带宽度和极高的热导率及优良的光学性质。金刚石基多晶材料潜在应用亟待研究和开发,例如作为陶瓷基板、热沉材料、微波窗口材料等。本文分别采用高温高压法、,通过扫描电子显微镜、荧光光谱仪、阻抗分析仪等研究了其微观形貌、电学、热学和光学等性质,并探讨了不同烧结方法对这些多晶材料的性能影响。研究结果表明: 高温高压快速烧结法制备的金刚石多晶材料,其具有近紫外发光特性。添加不同的过渡金属时,发现在低于Co共晶点温度时,具有低熔点高沸点的金属zn 元素以及si和Zn的混合添加剂能够促进金刚石的烧结和致密化,并且能够抑制金刚石的石墨化。对所得到的含zn金刚石多晶材料进行光致发光光谱的测试, 发现当激发波长为200nm时,PL光谱在紫外310到390nm的范围内发现了一系列的尖锐的荧光谱,。而此条件下烧结制备的含si 金刚石复合多晶材料具有较高的电阻率和高电压下的电阻稳定性;溶胶-凝胶低温常压烧结法制备的金刚石多晶材料电阻率比金刚石薄膜电阻率略大,但介电损耗更小。以柠檬酸为络合剂,利用溶胶凝胶法制备的金刚石多晶材料,,介电损耗降低到10~,具有很好的高频介电稳定性;与溶胶凝胶法相比,固相反应法制备的金刚石多晶材料烧结温度较高,气孑L率较大,多晶复合材料的介电常数与介电损耗也偏大。关键词:金刚石;高温高压:溶胶凝胶;多晶材料;功能特性 ABSTRACT Diamond has many pared with other semiconductor materials, such as low onstant,high band gap,good electron holemobility,high thermal conductivity and optical potential use ofpolycrystalline diamond asceramic substrate,heat sinkmaterials,and microwave window materials needs anurgent research thispaper,polycrystalline diamond was prepared by thehigh-temperature andhigh-pressure method,pressureless sintering of andsolid statereactionmethod, microstructure andelectrical, thermal,optical and otherproperties and theeffectsofdifferentsintering method had beeninvestigated bySEM,PL spectroscopy and impedance analyzer. The main findings ofthispaper were asfollows:the near ultravioletlight—emitting properties ofpolycrystalline diamond materials prepared byhigh-temperature and high-pressure and rapid hadbeen shown thatthe metal element Znwith high boilingand low melting point could promote thesintering and densification of diamond below theCo eutectictemperature by differentphases oftransition metals polycrystalline diamond material photoluminescence spectra was investigated,it hadbeenfound that aseriesofsharp fluorescence spectra withthe emission linewidth athalfmaximum was lessthan ntn when the excitation wavelength Was