Abstract

Here, we report the enhanced optical and electrical properties of graphene oxide-silver nanoparticles (GO-AgNPs) nanocomposite due to thermal annealing in air at different temperatures (150, 250, and 350°C). Our findings show that the optical properties of the GO-AgNPs film strongly depend on the annealing temperature. With an increase in annealing temperature, the optical absorption band and photoluminescence (PL) band are monotonically shifted towards a longer wavelength with a slight increase in absorbance. Interestingly, annealing of the nanocomposite film at 350°C in the air results in the nitrogen-doping from air into GO lattice. Unlike the PL bands in the near-ultraviolet (UV) range in cases of GO-AgNPs annealed at 150 and 250°C, this film exhibits pronounced multiple PL bands in the visible range, which are attributed to optical transitions associated with the localized nitrogen defects incorporated from air under thermal annealing and charge transfer between AgNPs and carbon. Mechanisms of the observed optical properties are also discussed. Furthermore, thermal annealing of the film also affects its electrical properties. The sheet resistance of the film reduces with the increase of annealing temperature and its lowest value ~ 21 Ω/□ with transmittance ~ 82% at 550 nm is achieved at 350°C.

中文翻译：

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空气中的热退火增强了氧化石墨烯-银纳米颗粒纳米复合薄膜的光电性能

摘要

在这里，我们报告了由于在不同温度（150、250和350°C）下在空气中进行热退火，氧化石墨烯-银纳米颗粒（GO-AgNPs）纳米复合材料增强了的光学和电学性能。我们的发现表明，GO-AgNPs薄膜的光学性能在很大程度上取决于退火温度。随着退火温度的升高，光吸收带和光致发光（PL）带单调移向更长的波长，吸收率略有增加。有趣的是，纳米复合膜在空气中于350°C退火导致氮从空气掺杂到GO晶格中。与GO-AgNP在150和250°C退火的情况下在近紫外（UV）范围内的PL带不同，该膜在可见光范围内表现出明显的多个PL带，其归因于与在热退火下从空气中掺入的局部氮缺陷以及AgNP和碳之间的电荷转移有关的光学跃迁。还讨论了观察到的光学性质的机理。此外，薄膜的热退火也影响其电性能。薄膜的薄层电阻随着退火温度的升高而降低，并且在350°C时其最低值约为21Ω/□，在550 nm处的透射率约为82％。