Model-free determination of optical constants: application to undoped and Ga-doped ZnO
Model-free determination of optical constants: application to undoped and Ga-doped ZnO
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光学常数的无模型测定：在未掺杂和 Ga 掺杂 ZnO 中的应用
DOI：
10.1117/1.oe.56.3.034112
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发表时间：
2017
影响因子：
1.3
通讯作者：
K. Leedy
中科院分区：
文献类型：
--
作者：
D. Look;Buguo Wang;K. Leedy
抽象的。对于像大块半导体这样的均匀材料的单板，我们导出了吸收系数α和反射系数R的闭合表达式，它们分别由测量的反射比和透射率Rm和Tm表示。α的公式可以代替作为Tm的函数的几个常用的α近似，并且特别地不需要αd≫1，其中d是厚度。因此，它可以应用于弱杂质吸收，如掺铁GaN中铁的吸收。最后，折射率(n=η+Iκ)的实部(η)和虚部(κ)可以由α和R得到，与η和κ的实验结果符合得很好。对于多层结构，可以获得α、R、η和κ的“有效”值，但通常可以将它们分配给特定的层。这项技术已成功地应用于许多块状和层状结构。
Abstract. For single slabs of uniform material, such as bulk semiconductors, we derive closed-form expressions for absorption and reflection coefficients, α and R, respectively, in terms of measured reflectance and transmittance, Rm and Tm. The formula for α can replace the several commonly used approximations for α as a function of Tm and in particular does not require αd≫1, where d is the thickness. Thus, it can be applied to weak impurity absorptions, such as Fe absorption in Fe-doped GaN. Finally, the real (η) and imaginary (κ) parts of the index of refraction (n=η+iκ) can be obtained from α and R and agree well with η and κ results obtained from other experiments. For multilayer structures, “effective” values of α, R, η, and κ are obtained, but they can often be assigned to a particular layer. This technique has been successfully applied to many bulk and layered structures.