Abstract: “The efficiency of organic light-emitting diodes (OLEDs) strongly depends on the mobility of electric holes in the organic materials. To improve the performance of flexible OLEDs, various thicknesses of hole injection layers and hole transporting layers in the flexible OLEDs were studied in this work. The PEDOT:PSS hole injection layer was deposited on the ITO coated PET substrate by spin coating at the first, and then deposited the NPB hole transporting layer, Alq3 emitting layer, and aluminum cathode by thermal evaporation. The OLED component was covered with a PET film and packaged by UV glue in the final. The luminance, chromaticity coordinate, and life time of the flexible OLEDs were tested, where the thickness effects of the PEDOT:PSS and NPB on the OLED performance were also studied. The result showed that the flexible OLED stacked as PET /Al 200 nm /Alq3 100 nm /NPB 40 nm /PEDOT:PSS 130 nm /ITO /PET had the best performance with 2640.7 cd/m2 at 10 V.”

Keywords: OLED; flexible; hole injection layer; hole transport layer.