Provided is a composition A that includes: a first dopant; and a first host; where the first dopant has a HOMO energy HOMODopant and a LUMO energy LUMODopant; the first host has a HOMO energy HOMOHost and a LUMO energy LUMOHost; |LUMOHost−HOMODopant|=X1; |LUMODopant−HOMOHost|=X2; the first dopant has an optical bandgap energy, Y; at least one of X1 and X2 is less than or equal to Y+0.026 eV; the composition A has a vertical dipole ratio VDR(A); composition B is a reference composition comprising the first dopant and a second host, wherein the second host is the composition B having a vertical dipole ratio VDR(B); the ratio of the first dopant and the first host in the composition A is identical to the ratio of the first dopant and second host in the composition B; and VDR(A)−VDR(B) is ≥0.05.