In situ thickness dependent photoluminescence （PL） measurements of tris（8-hydroxyquinoline） aluminum（Alq3） film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showe...In situ thickness dependent photoluminescence （PL） measurements of tris（8-hydroxyquinoline） aluminum（Alq3） film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.展开更多
The optical properties of N,N’-bis (Inaphthyl)N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine (NPB) and tris (8-hydroxyquinolinato) aluminum (Alq3) organic materials used as hole transport and electron transport layers i...The optical properties of N,N’-bis (Inaphthyl)N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine (NPB) and tris (8-hydroxyquinolinato) aluminum (Alq3) organic materials used as hole transport and electron transport layers in organic light-emitting devices (OLED) have been investigated. The NPB and Alq3 layers were prepared using thermal evaporation method. The results show that the energy band gap of Alq3 is thickness independence while the energy band gap of NPB decreases with the increasing of sample thickness. For the case of photoluminescence the Alq3 with thickness of 84 nm shows the highest relative intensity peak at 510 nm.展开更多
A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternati...A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface formed between SiO2 and tris-(8-hydroquinoline) aluminum(Alq3) of SSCL device was investigated by using X-ray photoelectron spectroscopy(XPS).Analyses of the XPS spectra reveal a deep diffusion of the indium into the interface.On the other hand,the interaction between indium and Alq3 occurs at the interface and results in the formation of a carbon-oxygen-metal(In or Al) complex in the contact region.This effect causes a luminescence quenching in the SSCL device.展开更多
基金This work is supported by the National Natural Science Foundation of China （No. 10274072, 20240430654）the Specialized Research Fund for the Doctoral Program of Higher Education of China （No. 20030335017）.
文摘In situ thickness dependent photoluminescence （PL） measurements of tris（8-hydroxyquinoline） aluminum（Alq3） film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.
文摘The optical properties of N,N’-bis (Inaphthyl)N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine (NPB) and tris (8-hydroxyquinolinato) aluminum (Alq3) organic materials used as hole transport and electron transport layers in organic light-emitting devices (OLED) have been investigated. The NPB and Alq3 layers were prepared using thermal evaporation method. The results show that the energy band gap of Alq3 is thickness independence while the energy band gap of NPB decreases with the increasing of sample thickness. For the case of photoluminescence the Alq3 with thickness of 84 nm shows the highest relative intensity peak at 510 nm.
基金supported by the National Natural Science Foundation of China (Grant No. 60806047)the Natural Science Foundation Project of CQ CSTC (Grant No. 2009BB2237)+1 种基金the Science and Technology of Chongqing Municipal Education Commission (Grant No. KJ080816)the Natural Science Foundation of Chongqing Normal University (Grant Nos. 07XLB015 and 08XLS12)
文摘A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface formed between SiO2 and tris-(8-hydroquinoline) aluminum(Alq3) of SSCL device was investigated by using X-ray photoelectron spectroscopy(XPS).Analyses of the XPS spectra reveal a deep diffusion of the indium into the interface.On the other hand,the interaction between indium and Alq3 occurs at the interface and results in the formation of a carbon-oxygen-metal(In or Al) complex in the contact region.This effect causes a luminescence quenching in the SSCL device.
