We have used polyvinylcarbazole, PVK, in combination with poly(p‐phenylene vinylene), PPV and a green‐emitting, soluble derivative, poly(4,4′‐diphenylene diphenylvinylene) or briefly PDPV, to fabricate triple‐layer light‐emitting diodes PPV/PVK/PDPV/metal, with indium tin oxide as the anode. We report luminances in excess of 1300 cd/m2 with Al cathodes, turn‐on voltages of ∼8 V in structures 300 nm thick, and internal efficiencies in the range 0.4%–0.8% for Al and Ca cathodes; at least ten times higher than for single‐layer PDPV devices. Quantum efficiencies for Ca or Al electrodes are only a factor 1.5 different. The improvements over single‐layer PDPV devices are considered to be due to better hole injection by PPV and to the formation of a hole barrier at the PPV/PVK interface, which forces a better balance of the electron and hole currents. © 1996 American Institute of Physics.