We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes （PLEDs） based on green fluorescent polyfluorene derivative. The annealed PLEDs exh...We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes （PLEDs） based on green fluorescent polyfluorene derivative. The annealed PLEDs exhibit improved charge transport and red-shift emission compared to the as-fabricated device. The stability of the PLEDs is largely enhanced by post-annealing before and after Ca deposition, which is attributed to the enhanced charge transport and the intimate contact between the cathode and the emissive layer.展开更多
The performance of blue polymer light-emitting diodes （PLEDs） based on poly（9,9-dioctylfluorene） （PFO） is improved by introducing a thin layer of sodium hydroxide （NaOH） between the calcium cathode and the PFO...The performance of blue polymer light-emitting diodes （PLEDs） based on poly（9,9-dioctylfluorene） （PFO） is improved by introducing a thin layer of sodium hydroxide （NaOH） between the calcium cathode and the PFO emissive layer. By replacing the commonly used Ca/Al cathode by a NaOH （2.5nm）/Ca （10nm）/Al cathode, the driving voltage is reduced from 8.3 V to 5.4 V and the light-emitting efficiency is enhanced from 0.46cd/A to 0.72cd/A for achieving a luminance of 500cd/m^2, respectively. Moreover, the device with NaOH/Ca/Al cathode shows a pure blue emission of （0.17, 0.12） at high brightnesses. These improvements are attributed to introduction of a thin layer of NaOH that can lower the interracial barrier and facilitate electron injection.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 50573076, the National Basic Research Program of China under Grant No 2002CB613401, the Bai-Ren-Ji-Hua Programme of Chinese Academy of Sciences, and the Fund of National Key Laboratory of Integrated 0ptoelectronics of Jilin University （No 2006-JLU-01）.
文摘We investigate the effect of thermal annealing before and after cathode deposition on the stability of polymer light-emitting diodes （PLEDs） based on green fluorescent polyfluorene derivative. The annealed PLEDs exhibit improved charge transport and red-shift emission compared to the as-fabricated device. The stability of the PLEDs is largely enhanced by post-annealing before and after Ca deposition, which is attributed to the enhanced charge transport and the intimate contact between the cathode and the emissive layer.
文摘The performance of blue polymer light-emitting diodes （PLEDs） based on poly（9,9-dioctylfluorene） （PFO） is improved by introducing a thin layer of sodium hydroxide （NaOH） between the calcium cathode and the PFO emissive layer. By replacing the commonly used Ca/Al cathode by a NaOH （2.5nm）/Ca （10nm）/Al cathode, the driving voltage is reduced from 8.3 V to 5.4 V and the light-emitting efficiency is enhanced from 0.46cd/A to 0.72cd/A for achieving a luminance of 500cd/m^2, respectively. Moreover, the device with NaOH/Ca/Al cathode shows a pure blue emission of （0.17, 0.12） at high brightnesses. These improvements are attributed to introduction of a thin layer of NaOH that can lower the interracial barrier and facilitate electron injection.
