Diketopyrrolopyrrole based highly conjugated small molecules for organic solar cells

A series of three donor molecules (DPP-B, DPP-N and DPP-P) based on diketopyrrolopyrrole (DPP) sharing the similar backbone D-π-A-π-D have been investigated. In these molecules, substituents such as pyrene, naphthalene benzene act electron donating end groups, DPP central core unit thiophene has used a bridge between acceptor fragments. Theoretical calculations carried out with help density functional theory (DFT) time-dependent (TD-DFT). For optimization geometry investigated DFT B3LYP/6-31g(d) TD-B3LYP/6-31g(d) to obtain best results inexcited state. DPP-P considered suitable molecule among all it manifests value Eg 2.24 eV showed stronger absorption λmaxof 611 nm. Hence, this study reveals that are for high performance organic solar cell devices