Diketopyrrolopyrrole: A versatile building block for organic photovoltaic materials

In recent years, diketopyrrolopyrroles (DPPs) have become one of the extensively studied organic building blocks of oligomers and polymers having promising optoelectronic properties, especially in organic solar cells. There are a large number of reports on structural modification of DPP cores to improve their properties in devices. There is plenty of room left for research in the field of structural modification and bandgap engineering to maintain energy level alignment and to achieve optimum morphology/crystallinity leading to high performance in organic photovoltaic (OPV) devices. This article reviews the DPP containing materials and their variants as potential active layer materials for OPV devices. An attempt has been made to go through their synthesis, structure and optoelectronic properties in such a way that any future efforts to modify this versatile structure have benefited.