Flexible photodetectors, with applications ranging from large-scale photosensors to flexible solar cells and fiber-optical sensors, offer a promising avenue for technological advancement. Despite their high performance and stability, conventional inorganic photodetectors suffer from complex, costly manufacturing processes and lack mechanical flexibility. This gap is potentially bridged by organic semiconducting polymers (OSPs), which require enhancements in charge transport capabilities. Integrating exfoliated graphitic carbon nitride (C3N5) with OSPs, specifically into a poly(3-hexylthiophene-2,5-diyl) (P3HT) matrix, has shown to significantly improve electrical and optoelectronic properties due to C3N5's excellent optoelectronic features, adjustable bandgap, and stability. This study successfully fabricated flexible photodetectors with a P3HT/C3N5(3 %) mix in a Schottky barrier diodes (SBDs) configuration, achieving a 100-fold increase in photocurrent, exceptional flexibility, and rapid response to light. These findings highlight the potential of a synergistic approach in developing high-performance, commercially viable flexible photodetectors.