We introduce a thin LiF layer into tris-8-hydroxyquinoline aluminium （Alq3 ） based bilayer organic light-emitting devices to block hole transport. By varying the thickness and position of this LiF layer in Alq3, we ...We introduce a thin LiF layer into tris-8-hydroxyquinoline aluminium （Alq3 ） based bilayer organic light-emitting devices to block hole transport. By varying the thickness and position of this LiF layer in Alq3, we obtain an electroluminescent efficiency increase by a factor of two with respect to the control devices without a LiF blocking layer. By using a 10nm dye doped Alq3 sensor layer, we prove that LiF can block holes and excitons effectively. Experimental results suggest that the thin LiF layer may be a good hole and exciton blocking layer.展开更多
The effect of a benzimidazole derivative(TPBI)electron injection layer(EIL)on the performance of Alga based organic light-emitting devices(OLEDs)with a Cs_(2)C0_(3)/Al cathode is investigated.An increasing current den...The effect of a benzimidazole derivative(TPBI)electron injection layer(EIL)on the performance of Alga based organic light-emitting devices(OLEDs)with a Cs_(2)C0_(3)/Al cathode is investigated.An increasing current density from 71.9mA/cm2 to 188.3mA/cm^(2),and an enhanced electroluminescence(EL)efficiency from 3.2cd/A to 3.64 cd/A at 9 V are found when a thin TPBI layer(5 nm)is inserted at the Alq_(3)/Cs_(2)C0_(3)interface.After further increasing the TPBI thickness to 10 run,OLEDs display a further increase in EL efficiency to 4.53cd/A.Our experiment suggests that the TPBI thin layer at the Alq_(3)/Cs_(2)C0_(3)interface facilitates the electron injection and is also involved with hole-blocking and exciton confinement.展开更多
We present the experimental evidences showing that three different electron injection models play roles in Alq3 based organic light-emitting diodes in sequence when the thickness of LiF interlayer is changed. It is fo...We present the experimental evidences showing that three different electron injection models play roles in Alq3 based organic light-emitting diodes in sequence when the thickness of LiF interlayer is changed. It is found that the device with a 0.2nm LiF layer displays the largest current with declined luminescence. However, the one with a 0.6 nm LiF layer displays the second largest current and the highest luminescence of all. Combining with the photoluminescent test results, three models, namely chemical reaction at ternary interface, dipole effect at binary interface and tunneling enhancement effect, are expected to play roles in sequence when the LiF thickness is increased from 0 nm to 4 nm.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10504044, and the Fok Ying Tung Education Foundation under Grant No 101007.
文摘We introduce a thin LiF layer into tris-8-hydroxyquinoline aluminium （Alq3 ） based bilayer organic light-emitting devices to block hole transport. By varying the thickness and position of this LiF layer in Alq3, we obtain an electroluminescent efficiency increase by a factor of two with respect to the control devices without a LiF blocking layer. By using a 10nm dye doped Alq3 sensor layer, we prove that LiF can block holes and excitons effectively. Experimental results suggest that the thin LiF layer may be a good hole and exciton blocking layer.
基金Supported by the National Natural Science Foundation of China under Grant No 20972097Guangdong-Provincial Natural Science Foundation(No 031805)+2 种基金the Major Program in Key Field of Guangdong Province Government(No 2003-03)Science and Technology Program of Shenzhen(No 2006-2007)the Project 000011 Supported by SZU R/D Fund,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province.
文摘The effect of a benzimidazole derivative(TPBI)electron injection layer(EIL)on the performance of Alga based organic light-emitting devices(OLEDs)with a Cs_(2)C0_(3)/Al cathode is investigated.An increasing current density from 71.9mA/cm2 to 188.3mA/cm^(2),and an enhanced electroluminescence(EL)efficiency from 3.2cd/A to 3.64 cd/A at 9 V are found when a thin TPBI layer(5 nm)is inserted at the Alq_(3)/Cs_(2)C0_(3)interface.After further increasing the TPBI thickness to 10 run,OLEDs display a further increase in EL efficiency to 4.53cd/A.Our experiment suggests that the TPBI thin layer at the Alq_(3)/Cs_(2)C0_(3)interface facilitates the electron injection and is also involved with hole-blocking and exciton confinement.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61106094 and 20972097, the Natural Science Foundation of Guangdong Province under Grant No S2012020011003, the Foundation for Distinguished Young Talents in Higher Education of Guangdong under Grant No LYM11111, and the Shenzhen Science Foundation under Grant Nos JC201005280458A, JCYJ20130329115524512 and JCYJ20120613162231310.
文摘We present the experimental evidences showing that three different electron injection models play roles in Alq3 based organic light-emitting diodes in sequence when the thickness of LiF interlayer is changed. It is found that the device with a 0.2nm LiF layer displays the largest current with declined luminescence. However, the one with a 0.6 nm LiF layer displays the second largest current and the highest luminescence of all. Combining with the photoluminescent test results, three models, namely chemical reaction at ternary interface, dipole effect at binary interface and tunneling enhancement effect, are expected to play roles in sequence when the LiF thickness is increased from 0 nm to 4 nm.
