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
Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of inst...Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq3-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq3-based OLEDs. H20 molecules in envi- ronment can be firmly bound to the oxygen atoms of the facial Alq3, which then act as starting points for further de- gradation of Alq3. Moreover, the interactions between facial Alq3 and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq3 and improve the stability of materials applied in OLEDs.展开更多
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.
基金Supported by the National Natural Science Foundation of China（Nos.61307119, 61235004）.
文摘Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq3-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq3-based OLEDs. H20 molecules in envi- ronment can be firmly bound to the oxygen atoms of the facial Alq3, which then act as starting points for further de- gradation of Alq3. Moreover, the interactions between facial Alq3 and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq3 and improve the stability of materials applied in OLEDs.
