“…The enhancement was therefore attributed to the charge-transport properties of copolymer 981d, leading to confinement of charge on the MEH-PPV. Similar enhancements of the EL efficiency of MEH-PPV and other red-orange emitting alkoxy-PPVs have been reported by blending them with other green or blue emitting polymers 649, 2182 1142, 2183 385, 2184 389, 2184 1143, 2185 1020a-c, 2036 1144a, 2186 and 694a. 2187 In the last case, the emission is voltage-tunable between red (λ max ) 585 nm) and green (λ max ) 530 nm).…”