Graphene-Reinforced PVC/PMMA Flexible Substrates for Thin-Film Solar Cells

High Resolution Image Download MS PowerPoint Slide Flexible and lightweight substrates are essential for next-generation solar cells as they not only expand their applicability but also reduce the fabrication, logistics and operational costs. However, most polymeric materials lack thermal and mechanical stability required for thin-film photovoltaic processing. In this work, we developed and characterized polymeric blends of PVC/PMMA/DOP, decorated with exfoliated graphene, to serve as flexible bases for III–V thin film photovoltaics. The blends were prepared via solution casting and characterized chemically by FTIR, Raman, and X-ray photoelectron spectroscopy (XPS), morphologically by atomic force and scanning electron-microscopy, and thermo-mechanically by thermogravimetry and dynamic mechanical-analysis. The incorporation of exfoliated graphene markedly enhanced the thermal resistance of the blends, as evidenced by an increase of approximately 70 °C in the softening point due to the restricted mobility of the polymer chains. In addition, the increases observed in the glass transition temperature ( T g ), the elevation of the onset decomposition temperature ( T onset ), and the maximum degradation rate temperature ( T max ) further confirm the influence of graphene on the thermal integrity of the material. Spectroscopic and microscopic analyses confirmed good miscibility between PVC and PMMA and effective interaction with the plasticizer DOP. The optimized PVC/PMMA/DOP blend with dispersed exfoliated graphene exhibited the best balance between elasticity and thermal stability, remaining structurally intact up to 130 °C. These results demonstrate a low-cost, scalable approach for producing mechanically robust and thermally stable polymeric materials as optimal candidate substrates for flexible high-efficiency solar cells.