Optical Absorption of Polyvinyl Alcohol Films Doped with Nickel Chloride
Optical Absorption of Polyvinyl Alcohol Films Doped with Nickel Chloride
复制标题
掺杂氯化镍的聚乙烯醇薄膜的光吸收
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Dlear R. Saber
中科院分区：
文献类型：
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作者：
Omed Abdullah;Dlear R. Saber
采用浇铸法制备了掺杂不同浓度氯化镍（NiCl2）的纯聚乙烯醇（PVA）薄膜，研究了NiCl2添加量对PVA载体光学性能的影响。利用复折射率在190 ~ 1100 nm波长范围内研究了纯PVA薄膜和掺杂NiCl2的PVA薄膜的色散特性。吸收光谱分析表明，光能带是由直接和间接允许的光跃迁引起的。薄膜的光能带隙Egopt随NiCl2含量的增加而减小，而称为光带隙局域态宽度的乌尔巴赫能∆Et从0.7414 eV减小到0.1891 eV。在70℃退火3小时后，观察到所有样品的光能带隙减小。
Films of pure and doped Polyvinyl alcohol (PVA) with different concentration of Nickel Chloride (NiCl2) were prepared using the casting technique, in order to investigate the effect of NiCl2 additions on the optical properties of PVA host. The dispersion studies of pure PVA film and PVA films doped with NiCl2 were studied using complex refractive index in the wavelength range 190-1100 nm. The absorption spectral analysis showed that the optical energy band is due to the direct and indirect allowed optical transitions. The optical energy band gap Egopt of the films decreases with increasing NiCl2 contents, while the Urbach energy ∆Et called the width of localized states in the optical band gap decreases from 0.7414 to 0.1891 eV. The reductions of optical energy band gap were observed for all samples after annealing at temperatures 70oC for three hours.