Abstract In the quest for developing new and advanced technologies, semiconductor band gap engineering is critical. In this study, chitosan/multi-walled carbon nanotube (CS/MWCNT) bio-nanocomposite films were prepared using a simple, environmental-friendly and cost-effective method, and the changes occurring in optical band gap energies (Eg) were examined with Tauc and Absorbance Spectrum Fitting (ASF) methods. The results of both models were found to be very close to each other. The optical and electrical properties of the bio-nanocomposites were significantly improved, which make them promising materials for ultraviolet protection, coating and optoelectronic applications. In addition, Urbach energies (Eu) (Band tails) and optical parameters of CS/MWCNT bio-nanocomposites such as refractive index (n), absorption (α) and extinction (k) coefficient were investigated. Urbach energy levels and refractive index values were increased with the increase of MWCNT content in CS matrix. The obtained low band gap energies of the composites by adding MWCNT were interpreted as evidence that the electrical conductivity of the composites is increased and this behavior was found to be consistent with surface conductivity measurements of the composites.

中文翻译：

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用 Tauc 和 ASF 方法测定 CS/MWCNT 生物纳米复合材料的光学带隙能量

摘要 在开发新技术和先进技术的过程中，半导体带隙工程至关重要。在这项研究中，使用简单、环保和具有成本效益的方法制备了壳聚糖/多壁碳纳米管 (CS/MWCNT) 生物纳米复合薄膜，并研究了光学带隙能量 (Eg) 发生的变化Tauc 和吸光度光谱拟合 (ASF) 方法。发现两个模型的结果彼此非常接近。生物纳米复合材料的光学和电学性能得到显着改善，使其成为用于紫外线防护、涂层和光电应用的有前途的材料。此外，CS/MWCNT 生物纳米复合材料的 Urbach 能量 (Eu)（带尾）和光学参数，如折射率 (n)、研究了吸收（α）和消光（k）系数。Urbach 能级和折射率值随着 CS 基质中 MWCNT 含量的增加而增加。通过添加 MWCNT 获得的复合材料的低带隙能量被解释为复合材料电导率增加的证据，并且发现这种行为与复合材料的表面电导率测量结果一致。