Abstract:
The design of low-bandgap organic semiconductors with strong absorption, favorable redox properties, and efficient charge transport is critical to advancing organic photovoltaics (OPVs). In this work, we report the synthesis of a series of naphthyl chalcone derivatives via Claisen-Schmidt condensation and their comprehensive evaluation using photophysical, electrochemical, and theoretical methods to assess their suitability for photovoltaic applications. UV- Vis absorption studies revealed strong solvent-dependent behavior, with maxima observed in the 380-460 nm range. The emission profiles, extending up to 560 nm, demonstrated pronounced solvatochromism, indicative of excited-state intramolecular charge transfer. Stokes shifts ranging from 80 to 157 nm suggested significant reorganization between ground and excited states, with larger shifts observed in molecules bearing strong electron-donating substituents. Electrochemical analysis using cyclic voltammetry showed quasireversible redox behavior and revealed HOMO-LUMO energy gaps in the range of 2.8-3.2 eV. The incorporation of electron-rich or electron- deficient substituents allowed for tuning of both optical and electrochemical properties. Notably, compounds with electron- donating aryl moieties such as dimethylamino exhibited higher fluorescence intensity. To support and rationalize the experimental findings, DFT and TD-DFT calculations were performed using the B3LYP/6-31G(d,p) level of theory. The computed absorption wavelengths were in good agreement with experimental data. Frontier molecular orbital analysis revealed strong donor-acceptor interactions across the p-system. Key computational descriptors, including dipole moments, density of states, transition density matrices, reorganization energies, and charge transfer integrals, were extracted to provide a deeper understanding of charge transport behavior and molecular stability. The combined photophysical, electrochemical, and computational results point toward favorable structureproperty relationships in the scaffold. The large Stokes shifts, broad absorption, and effective intramolecular charge transfer support their potential as donoracceptor systems in organic optoelectronics. Furthermore, their tunable HOMOLUMO levels and moderate fluorescence output make them attractive for integration into multilayered OPV devices, where controlled energy level alignment and charge mobility are essential for optimal power conversion efficiency. This study emphasizes combining experiments and computational modeling to design OPV materials. The investigated chalcones show promise, and future work aims to optimize them for better NIR absorption, stability, and device compatibility.
Page(s):
90-91
DOI:
DOI not available
Published:
Journal: 4th International Conference of Sciences “Revamped Scientific Outlook of 21st Century, 2025” , November 12,2025, Volume: 1, Issue: 1, Year: 2025
Keywords:
Electrochemical Analysis
,
Charge mobilities
,
DFT calculations
,
Naphthyl chalcones
,
DOS analysis
,
LippertMatga plots
,
Stokes shift analysis
,
Photophysical properties