Analysis of dipyridine dipyrrole based molecules for solar cell application using computational approach

In this work, six dipyridine dipyrrole (DPDP) derivatives are reported as π-conjugated, electron donor molecules used in BHJ solar cells. Density functional theory (DFT) method with the Becke three-parameter, hybrid functional combined with the Lee, Yang, and Parr correlation functional (B3LYP) taking 6-311G(d) basis set supported by the Gaussian 09 program has been employed for the determination of the structural, geometrical and molecular electrostatic potential. Absorption properties have been examined employing the time-dependent density functional theory (TD-DFT) method with B3LYP functional and 6-311G(d) basis set. Two major photovoltaic parameters for predicting the efficiency of the bulk heterojunction (BHJ) solar cell for power conversion, namely, open-circuit voltages (Voc) and light-harvesting efficiencies (LHE), are studied. The π-conjugated molecules, due to their alternate π-bonds and lower bandgap energy (Egap), possess excellent photovoltaic properties, and large photocurrent generation is obtained upon light absorption. The reported molecules can be used as electron donor molecules in the active part of the BHJ devices to generate photoelectronic current based on their studied properties. The reported molecules can be easily synthesized and have properties like mechanical flexibility, non-toxicity, low-cost production platform, and biodegradability.