氧化锆（ZrO_2）的电、光性质与应用

重点分析了ZrO2的电子结构与能带特点、光学吸收、发射谱等,介绍了第一原理法计算不同晶相ZrO2的能带结构和电子能量状态密度图（DOS）的结果,在计算能级结构的基础上,归纳了不同晶相的ZrO2在禁带附近可能的电子跃迁机理及其相应的能量,说明了无论是高纯ZrO2还是掺杂ZrO2,在室温下均表现出高的绝缘性能。分析了高温下ZrO2导电能力提高的原因,高温导电性可应用于氧传感器和燃料电池中的电极隔膜材料。掺杂后的ZrO2晶体的透光性非常好,且在较高温度的环境中,如果不发生晶体结构转变或失透等,则温度对提高晶体的折射率有积极的作用。ZrO2粉体的白色外观是由于粉体的表面对可见光的散射以及晶体内部的大量缺陷对光的散射作用。介绍了纯ZrO2材料的发光效应来源在于捕获了电子的氧空位形成的新能级与基态能级间的跃迁,氧空位形成的F-色心或缔合中心而产生。指出ZrO2可以作为发光离子基质的原因在于作为宽禁带的ZrO2的声子能量较低,可为发光中心的稳定发光提供刚性场所。

Electronic and Optical Properties of ZrO2 and Its Applications

This review analyzed the band structure, optical absorption and emission spectra of ZrO2. The DOS and band structures of ZrO2 with different crystallographic types are introduced based on the first principal calculating to the energy structures. Possible transition mechanisms and energy gaps of electrons near the forbidden band of ZrO2 with different structures are analyzed based on the DOS calculations. Either pure or doped ZrO2 has a high insulation performance at room temperature. Conductivity of ZrO2 at high temperature is analyzed, and the applications in the fields such as oxygen sensor and the fuel cell separator materials are introduced. Doped ZrO2 crystal is highly light translucency, the high tem- perature has a positive effect to improve the refractive index of ZrO2 if the crystal does not occur structural changing or de- vitrification. The white appearance of ZrO2 powder is due to the light scattering on the surface and by the intrinsic defects. Luminescence in ZrO2 is originated from the transitions between ground state and the new energy levels created by oxygen vacancies, which captured electrons to form F-centers and their combined sites. Finally, the authors point out that ZrO2 can serve as light-emitting ions＇ matrix because of the low phonon energy and the wide band gap of ZrO2 , which provides rigid circumstance for the light emission centers.