Access to clean and affordable energy remains a global challenge. By 2030, approximately 645 million people may still lack access to electricity, and 1.8 billion could continue to rely on polluting fuels. 

To address this, scientists are investigating new light-harvesting and nonlinear optical (NLO) materials that can convert light into usable energy more efficiently.

In this work, a Schiff base compound, 3-((E)-((4-(((E)-3-nitrobenzylidene)amino)phenyl)imino)methyl)phenol (NBA), was examined. Using a computational chemistry approach, its electronic, optical, and NLO properties were analyzed.

NBA exhibited a small energy gap, strong charge transfer, high light-harvesting efficiency, and excellent polarizability. Its first and second hyperpolarizability values were nearly 100 times higher than those of urea, the standard NLO reference. These findings suggest NBA could be a promising material for solar energy devices, optical switches, and photodetectors. This supports SDG 7 (Affordable and Clean Energy) and SDG 12 (Responsible Consumption and Production).