Dopant-free hole transport materials for perovskite solar cells and donor molecules for organic solar cells

Abstract

This work aimed to create new Ullazine derivatives as hole-transporting materials (HTMs) for perovskite solar cells (PSCs) and donor materials for organic solar cells (OSCs). The newly devised compounds (UM1-UM6) exhibit much smaller energy band gaps and a broader λ_max than the UMR because of their strong electron-attracting groups. While UMR has a bandgap of 3.37 eV, the produced molecules ranged from 1.45 to 2.08 eV. The λ_max of UM1-UM6 in DCM are 376–460 nm, while the λ_max value of UMR is 408 nm. The reference UMR has a λ_h value of 0.008164 eV, whereas the computationally computed λ_h values of the UM1-UM6 created molecules range from 0.003777 to 0.008791 eV. Reason being, the acceptor moieties of these compounds make hole transit easier. Furthermore, after all of the newly created molecules were scaled with a PC₆₁BM acceptor, the Voc values were comparable to or higher than the reference, suggesting that these molecules are in a good position to increase efficiency. In terms of PCE (6.27 to 12.33 %), the newly created compounds (UM1-UM6) perform better than the reference compound (PCE = 7.80 %). The newly designed compounds (UM1-UM6) have the potential to be used as noble HTMs in the development of more advanced perovskite solar cells (PSCs) and donor molecules for organic solar cells (OSCs) in the future.