In the last few years, advanced polymers and related composite materials have attracted extensive attention and been widely studied and used in the energy field such as dye-sensitized solar cells, hole-transfer materials in perovskite solar cells, organic field-effect transistors, fuel cells, and fossil energy. Recently, the potential use of polymer materials for energy technology has been studied intensely. Research has been focused on molecular design concepts, synthesis of conjugated polymers with high charge transfer mobility, suitable highest occupied molecular orbital and lowest unoccupied molecular orbital, and broad optical absorptions. The result of this research shows semiconductor-like behavior in polymers and highlights their usage in constructing low-cost, flexible, high-performance electronic devices. It is essential to focus more efforts on exploring advanced technologies for the utilization of advanced polymers or related composite materials in the energy field.

In this special issue, studies related to polymers and their related composite materials for energy applications, especially covering the above-mentioned hot topics, are expected to attract numerous submissions. Furthermore, review articles covering these topics are welcomed.

Potential topics include but are not limited to the following:

• Molecular design technique to synthesize advanced polymers for use in electronic devices
• The applications of advanced polymers or related composites used in electronic devices such as solar cells and organic field-effect transistors
• Performance evaluation of advanced polymers or related composites utilized in solar/electronical devices
• Fundamental mechanisms of the application of polymers in high-efficiency energy supply