Improve efficiency by surface treatment of top-emission flexible polymer light-emitting diode

A yellow flexible top-emission polymer light-emitting diode (TOPLED) was fabricated on cyclic olefin copolymer (COC) substrate. The light-emitting material was phenyl-substituted (p-phenylene vinylene) (HYPPV) polymer. The structure of TOPLED was COC/Ag/PEDOT:PSS/HYPPV/Ca/Ag. The Ag on COC was used as anode and the Ag on Ca was used as cathode. After anode Ag was thermally evaporated on COC substrate, the ultraviolet-ozone (UV-ozone) was treated on surface of anode Ag. The treating time was varied. The optimal treated time was 3 minutes. The luminous efficiency of TOPLED increased 42% with 3 minutes UV-ozone treatment.