Structure, refractive-index dispersion and the optical absorption edge of chemically deposited ZnxCd(1-x)S thin films
Structure, refractive-index dispersion and the optical absorption edge of chemically deposited ZnxCd(1-x)S thin films
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DOI：
10.1007/s003390100877
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发表时间：
2002-02
期刊：
影响因子：
--
通讯作者：
A. Salem
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文献类型：
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作者：
A. Salem
硫化锌镉（ZnxCd(1-x)S）薄膜是通过一种简单且廉价的化学浴沉积方法，使用硫脲作为硫离子源从水介质中沉积出来的。沉积薄膜的结构已通过 X 射线衍射和透射电子显微镜进行了表征。从X射线衍射观察到沉积薄膜本质上是非晶态的。然而，在 423 K 退火 1.5 小时的 ZnxCd(1-x)S 薄膜显示出具有较小散射体积的晶体结构。所获得的结果在整个透射电子显微镜和相应的电子衍射图案中得到证实。使用 300–2500 nm 波长范围内的透射和反射光谱估算成分范围 0≤x≤1 的 ZnxCd(1-x)S 薄膜在 423 K 下退火 1.5 小时的光学常数。带隙随 x 值非线性变化。折射率对波长的依赖性服从单振荡模型，由此确定色散参数和高频介电常数。还给出了表面和体积能量损失函数的图形表示。
Zinc cadmium sulfide, ZnxCd(1-x)S, thin films have been deposited by a simple and inexpensive chemical bath deposition method from an aqueous medium using thiourea as a sulfide-ion source. The structure of the deposited films has been characterized by X-ray diffraction and transmission electron microscopy. It was observed from X-ray diffraction that the as-deposited films were amorphous in nature. However ZnxCd(1-x)S films annealed at 423 K for 1.5 h show a crystalline structure with a small scattering volume. The obtained results were confirmed throughout the transmission electron microscopy and the corresponding electron-diffraction patterns. The optical constants of ZnxCd(1-x)S films annealed at 423 K for 1.5 h in the compositional range 0≤x≤1 were estimated using transmission and reflection spectra in the wavelength range 300–2500 nm. The band gap varies non-linearly with the value of x. The dependence of the refractive index on the wavelength obeys the single-oscillation model, from which the dispersion parameters and the high-frequency dielectric constant were determined. A graphical representation of the surface and volume energy-loss functions was also given.