Small molecule based mixed interlayer for color control of solution processed multilayer white polymer light-emitting diodes

Solution processed multilayer stacked white polymer light-emitting diodes (WPLEDs) with small molecule based interlayer for color and charge balance management were developed. The multilayer stacked WPLEDs were fabricated by a stamp transfer printing method and a mixed interlayer of 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA) and 3-(biphenyl-4-yl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ) was inserted at the interface between a yellow and a blue emitting layer. Electroluminescence spectra and efficiency of the multilayer stacked WPLEDs could be effectively managed by changing the composition of the TCTA:TAZ mixed interlayer.