[Cu(bpy)(P^P)]+ containing light-emitting electrochemical cells: improving performance through simple substitution

Light-emitting electrochemical cells (LECs) containing [Cu(POP)((NN)-N-Lambda)][PF6] (POP = bis(2-diphenylphosphinophenyl)ether, (NN)-N-Lambda = 6-methyl- or 6,6'-dimethyl-2,2'-bipyridine) exhibit luminance and efficiency surpassing previous copper(I)-containing LECs.