A convenient strategy to develop sp² hybridized fused Y123 monomers for photovoltaic and optical ON-OFF switches with economic energy offsets

This paper presents a design strategy, their efficient visible light converting optimizations offsets and dye anchorage utility as N-doped fused ring electron acceptors of organic dye Y123 in photovoltaic and optical devices. Five novel dyes (Y1–Y5) are investigated, identifying major electronic contributions. Results shows favourable energy levels and oscillator strengths (f) for efficient charge transfer upon photoexcitation. The dye Y1 had an ionization potential (IP) of 3.00eV, electron affinity (EA) of 1.01eV, and dipole moment of 2.01D. The dye Y3 exhibited a high global hardness (η) of 0.85 and low softness (σ) of 0.12eV, indicating stability and strong electron-accepting ability. Evaluation of photovoltaic performance revealed impressive characteristics, such as Y2 with a light harvesting efficiency (LHE) of 98 %, open-circuit voltage of 1.74eV, fill factor of 0.9235, and short-circuit current (J_sc) density of 50.92 mA/cm², resulting in a maximum power output (P_max) of 81.82W. This study also included a detailed analysis of transition density matrix (TDM) and electron-hole overlap, providing insights into exciton dissociation and charge separation mechanisms in Y123 dyes. These analyses enhance the design of efficient N-doped fused ring electron acceptors for organic photovoltaic and optical devices. The study demonstrates the potential of N-doped fused ring electron acceptors as promising materials for efficient energy conversion in next-generation organic photovoltaic and optical devices.