Tunable structural, optical, and electrical performance of PEMA/PMMA–CoCl₂ composites for advanced optoelectronics and energy storage applications
F. E. Hanash, Maha A. Alenizi, G. M. Asnag, A.A. Al‐Muntaser, M. O. Farea, Sadiq H. Khoreem, A. Y. Yassin
Abstract
This work investigates the effects of CoCl₂ doping on the structural, optical, and impedance characteristics of PEMA/PMMA blends for the advancement of sophisticated polymeric multifunctional materials. Composite films containing CoCl₂ were prepared using the solution-casting method and characterized by various analytical techniques. XRD and FTIR analysis revealed reduced crystallinity with significant interactions in the doped samples, SEM revealed a homogeneous morphology with slight porosity as a result of filler incorporation. UV-Vis spectra have demonstrated a systematic decrease of both direct and indirect band gaps, which evidences an effective tuning of the electronic structure via controlled doping. Electrical studies have demonstrated a significant increase of ionic conductivity at higher CoCl₂ content, which was further supported by impedance spectra that have revealed a lower bulk resistance and better charge transport. Conducing equivalent-circuit models further confirmed and quantified these improvements in conductivity. This is a dual-polymeric (PEMA/PMMA) matrix doped with CoCl₂, hence attaining the simultaneous control of structural order, optical properties, and ionic transport each rarely observable in convention polymer films. The optimized 5.0 wt.% composite exhibits an excellent balance between the conductivity and structural stability and, hence, is considered a promising candidate for tunable optoelectronic and energy storage applications.