3-Fluoro-4-bromobenzyl bromide (4BFBB) is an organic compound that is a member of the class of halogenated aromatic compounds. This molecule has a set of isomers, which are in the same family and have the same chemical formula but different arrangements of atoms. 4BFBB has been used as an acceptor material for organic solar cells with experimental success. It absorbs light in the visible spectrum and transfers electrons to pbdb-t, increasing the efficiency of solar cells. The fluorine atoms in 4BFBB interact with other molecules due to their high electronegativity, making them useful for chemical reactions.