A novel polymer composite with a small optical band gap: New approaches for photonics and optoelectronics

作者:Aziz Shujahadeen B; Abdullah Omed Gh; Rasheed Mariwan A
来源:Journal of Applied Polymer Science, 2017, 134(21): 44847.
DOI:10.1002/app.44847

摘要

<jats:title>ABSTRACT</jats:title><jats:p>In this article, a novel approach is presented for the preparation of small band‐gap polymer composites. The intensity of the surface plasmon resonance (SPR) peak increased from 0.64 to 3.2 for the chitosan–silver nitrate sample containing 1 wt % titanium dioxide (TiO<jats:sub>2</jats:sub>). In the cases of 3 and 5 wt % added TiO<jats:sub>2</jats:sub> particles, the SPR peak disappeared. A wide shift of the absorption coefficient from 4.36 to 0.93 eV was observed. The smallest optical band gap of about 0.98 eV was achieved for the sample containing 3 wt % TiO<jats:sub>2</jats:sub> filler. The wide shift in the optical band gap was interpreted on the bases of the formation of metal‐induced gap states between the metallic silver particles and the TiO<jats:sub>2</jats:sub> structure. A novel approach was achieved that was an alternative method to Tauc's semi‐empirical model for band‐gap estimation. The optical dielectric loss parameter for the band‐gap study was easily calculated and analyzed, whereas it unfolded a deep knowledge from the physics point of view. The established quantum mechanical expression revealed a strong relationship between the energy band gap and the optical dielectric loss parameter. The scanning electron microscopy results show the leakage of white aggregated silver particles and distinguishable intense peaks of metallic silver particles between 3 and 3.3 keV appearing in the energy‐dispersive X‐ray spectrum.

  • 出版日期2017-6