Aromatic polymer films with high glass transition temperatures (T_g) exhibit superior thermal stability, making them ideal for high-temperature dielectric capacitors in advanced electrical and electronic systems. However, the leakage current can be intensified at high temperatures due to stronger π-electron delocalization, leading to energy loss and degrading capacitive performance. Here, we present a poly sulfonated aramid (PSA) derived from aramid by molecular engineering, with T_g > 300 °C. Sulfone groups with a non-planar structure are introduced to break strong π–π conjugation and subsequently suppress intramolecular charge transfer. Moreover, their large dipole moments contribute to a high dielectric constant. To suppress intermolecular charge transfer, organic small molecules of triptycene (TE) are filled at an optimized content, breaking π–π stacking among PSA chains. The activation energy for trapped carriers is further increased, while the hopping distance is shortened. The PSA/TE all-organic film achieves an energy density (U_d) of 5.71 J cm⁻³ at an efficiency exceeding 90% and a maximum U_d of 9.03 J cm⁻³ at 150 °C. Additionally, sulfone groups also aid self-healing by generating more gaseous products during pyrolysis. A roll-to-roll production line is established for continuously fabricating large-scale and high-quality PSA-based films, allowing for industrial potential for high-temperature capacitive energy storage.

Since atomically thin two-dimensional (2D) graphene was successfully synthesized in 2004, it has garnered considerable interest due to its advanced properties. However, the weak optical absorption and zero bandgap strictly limit its further development in optoelectronic applications. In this regard, other 2D materials, including black phosphorus (BP), transition metal dichalcogenides (TMDCs), 2D Te nanoflakes, and so forth, possess advantage properties, such as tunable bandgap, high carrier mobility, ultra-broadband optical absorption, and response, enable 2D materials to hold great potential for next-generation optoelectronic devices, in particular, mid-infrared (MIR) band, which has attracted much attention due to its intensive applications, such as target acquisition, remote sensing, optical communication, and night vision. Motivated by this, this article will focus on the recent progress of semiconducting 2D materials in MIR optoelectronic devices that present a suitable category of 2D materials for light emission devices, modulators, and photodetectors in the MIR band. The challenges encountered and prospects are summarized at the end. We believe that milestone investigations of 2D materials beyond graphene-based MIR optoelectronic devices will emerge soon, and their positive contribution to the nano device commercialization is highly expected.