An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn...An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.展开更多
The experimental study on negative capacitance（NO） of various light-emitting diodes（LEDs） is presented. Experimental result shows that all LEDs display the NO phenomenon. The voltage modulated electroluminescence...The experimental study on negative capacitance（NO） of various light-emitting diodes（LEDs） is presented. Experimental result shows that all LEDs display the NO phenomenon. The voltage modulated electroluminescence（VMEL） experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence. The measures also verify that the dependence of NO on voltage and frequency in different LEDs is similar. NO phenomenon is more obvious with higher voltage or lower frequency.展开更多
High efficiency of near infrared polymer light-emitting diodes with bilayer structure was obtained. The diode structure is ITO/PEDOT/L1/L2/Ba/Al, where L1 is phenyl-substituted poly [p-phenylphenylene vinylene] de- ri...High efficiency of near infrared polymer light-emitting diodes with bilayer structure was obtained. The diode structure is ITO/PEDOT/L1/L2/Ba/Al, where L1 is phenyl-substituted poly [p-phenylphenylene vinylene] de- rivative (P-PPV), L2 is 9,9-dioctylfluorene (DOF) and 4,7- bis(3-hexylthiophen)-2-yl-2,1,3-naphthothiadiazole (HDNT) copolymer (PFHDNT10). The electroluminescence (EL) spectrum of diodes from PFHDNT10 is at 750 nm located in the range of near infrared. The maximum external quantum efficiency is up to 2.1% at the current density of 35 mA/cm2. The improvement of the diode’s performances was consid- ered to be the irradiative excitons confined in the interface between L1 and L2 layers.展开更多
基金the National Natural Science Founda- tion of China (No. 20671068 and 20471041)
文摘An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.
基金This workis supported by the National Nature Science Founda-tion (Grant No.DMR-60376027)
文摘The experimental study on negative capacitance（NO） of various light-emitting diodes（LEDs） is presented. Experimental result shows that all LEDs display the NO phenomenon. The voltage modulated electroluminescence（VMEL） experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence. The measures also verify that the dependence of NO on voltage and frequency in different LEDs is similar. NO phenomenon is more obvious with higher voltage or lower frequency.
基金This work was supported by the State 973 Project(Grant No.2002CB6 13405)the National Natural Science Foundation of China(Grant No.90201023).
文摘High efficiency of near infrared polymer light-emitting diodes with bilayer structure was obtained. The diode structure is ITO/PEDOT/L1/L2/Ba/Al, where L1 is phenyl-substituted poly [p-phenylphenylene vinylene] de- rivative (P-PPV), L2 is 9,9-dioctylfluorene (DOF) and 4,7- bis(3-hexylthiophen)-2-yl-2,1,3-naphthothiadiazole (HDNT) copolymer (PFHDNT10). The electroluminescence (EL) spectrum of diodes from PFHDNT10 is at 750 nm located in the range of near infrared. The maximum external quantum efficiency is up to 2.1% at the current density of 35 mA/cm2. The improvement of the diode’s performances was consid- ered to be the irradiative excitons confined in the interface between L1 and L2 layers.
