In this study, the electronic and optical properties of polyaniline were systematically investigated using density functional theory (DFT) within the Vienna Ab Initio Simulation Package (VASP). Structural optimization was performed to ensure the stability of the polymer configuration prior to electronic and optical analyses. The calculations revealed a characteristic density of states and an electronic band gap of approximately 3.77 eV, indicating semiconducting behavior with potential for optoelectronic applications. From an optical standpoint, several key parameters were extracted, including the absorption coefficient and dielectric function, both showing a pronounced absorption peak in the ultraviolet (UV) region, suggesting strong photon–matter interaction in this energy range.

The strong UV absorption, combined with the wide band gap, positions polyaniline as an excellent candidate for a range of optoelectronic devices. These properties make it particularly attractive for organic solar cells, UV photodetectors, optical sensors, and light-emitting devices, where materials with high optical stability and strong absorption are critical for efficient performance. Additionally, the intrinsic structural tunability, high environmental stability, and chemical versatility of polyaniline enable easy processing, doping, and functionalization, broadening its applicability in flexible electronics, wearable technologies, and advanced photonic systems.

Overall, the results highlight polyaniline as a promising and versatile material for next-generation optoelectronic and photonic technologies, offering a desirable balance between performance, scalability, and cost-effectiveness. Future research directions could involve experimental validation, exploration of doped or composite forms of polyaniline, and investigation of device-level integration to fully harness its potential for commercial applications.