Copolymerization is one of the best methods to tune and enhance the photophysical and optoelectronic properties of choice monomers. In this view, current work proposed the copolymerization of o-phenylenediamine and thiophene via chemical oxidative polymerization to tune the optical properties such as oscillator strength, bandgap, quantum yield. Modifications by copolymerization were confirmed by doing UV–Vis and fluorescence studies via the oscillator strength and quantum yield which were enhanced by copolymerization. These studies were supported by finite difference time domain (FDTD) simulation studies. XRD and TEM studies suggested an increment in crystallinity upon functionalization via copolymer formation and doping. Thermal analysis disclosed tuned thermal stability for copolymer compared to its homopolymers while ¹H NMR confirmed the presence of various protons in the copolymer and doped copolymer. These observations propose its potential for various applications in optoelectronic devices such as OLEDs, sensors, organic solar cells, etc.