Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically,...Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.展开更多
A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photolu...A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m(2) and 0.31 m/W, respectively.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61176043)the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong Province,China(Grant Nos.2010A081002005,2011A081301003,and 2012A080304016)the Youth Foundation of South China Normal University(Grant No.2012KJ018)
文摘Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.
基金This work was supported by National Natural Science Foundation of China(No.69637010).
文摘A blue dye, 1-benzqthiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m(2) and 0.31 m/W, respectively.
