Faculty of Science, Physics Department, Cairo University, Giza, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Nov;97:1115-9. doi: 10.1016/j.saa.2012.07.126. Epub 2012 Aug 8.
Polycrystalline carbon nitride thin films were prepared by electrolysis of methanol-urea solution at different concentrations of urea to methanol and applied voltage 800 volts for 10h. Grazing incidence X-ray diffraction (GIXRD) revealed that the crystalline structure of carbon nitride films at moderate nitrogen content changed from amorphous phase to polycrystalline α-C(3)N(4), and β-C(3)N(4) phases. The optical transmission analysis of the films revealed that the band gap value for indirect allowed transitions increased with increasing nitrogen content, while the associated phonon energy value showed the opposite behavior. The refractive index and the extinction coefficient of the samples deposited with different concentrations were determined as a function of wavelength. The refractive index decreases with increasing both nitrogen content and crystallinity. The refractive index dispersion for the investigated samples is discussed in terms of the single oscillator model and oscillator parameters.
多晶氮化碳薄膜通过在不同浓度的甲醇-尿素溶液中电解，在 800 伏特的电压下施加 10 小时来制备。掠入射 X 射线衍射（GIXRD）表明，在中等氮含量下，氮化碳薄膜的晶体结构从非晶相转变为多晶α-C(3)N(4)和β-C(3)N(4)相。薄膜的光透射分析表明，间接允许跃迁的带隙值随着氮含量的增加而增加，而相关的声子能量值则表现出相反的行为。不同浓度沉积的样品的折射率和消光系数作为波长的函数被确定。折射率随着氮含量和结晶度的增加而降低。用单振子模型和振子参数讨论了所研究样品的折射率色散。
