Enhanced luminance (L) and luminous efficiency (LE) of polymer light-emitting diodes (PLEDs) is demonstrated using poly(bis(tetraphenyldiamino)biphenyl-perfluorocyclobutane), poly(BTPD-Si-PFCB), as the hole injection layer. The monomer is cast directly onto the indium-tin-oxide anode and thermally polymerized in situ. Hole injection from poly(BTPD-Si-PFCB) into the “super yellow” derivative of poly(phenylene vinylene) and into several blue-emitting polymers is comparable to or better than that from poly(ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSSA). With poly(BTPD-Si-PFCB) as the hole injecting layer into “super yellow,” the performance is identical to that obtained with PEDOT:PSSA (LE≈8 cd/A with little fall-off, even at L≫104 cd/m2). © 2003 American Institute of Physics.