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
By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically ...By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent materials were discussed. The regularities and characteristic of energy bands of Gaq3 and its derivatives were also investigated. The results show that the electronic π-π* transitions in Gaq3 are localized on the quinolate ligands. The emission of Gaq3 is due to the electron transitions from a phenoxide donor to a pyridyl acceptor. Two possible electron transfer pathways are presented, one by carbon atoms, and the other via metal cation Ga3+. The derivatives of Gaq3 may possess high luminescence efficiency.展开更多
The rate of batch extraction of gallium from alkaline aqueous solution was studied by adding 2-ethylhexanoic acid in organic phase containing 7-substituted-8-hydroxyquinoline(extractant N601), n-decanol and kerosene.T...The rate of batch extraction of gallium from alkaline aqueous solution was studied by adding 2-ethylhexanoic acid in organic phase containing 7-substituted-8-hydroxyquinoline(extractant N601), n-decanol and kerosene.The extraction of Ga can be considered as a pseudo-homogeneous first-order reac- tion.The neutralization and distribution of organic acid between phases during the extraction were studied. The effect of 2-ethylhexanoic acid on the protonation of N601 is insignificant.The extraction of HCl during the stripping of gallium is mainly dependent on the concentration of aqueous hydrochloric acid and the con- tent of N601.Under the given conditions of temperature and N601 content,the acidity of organic phase is a linear function of the concentration of carboxylic acid in organic phase and the concentration of hydrochloric acid in equilibrium aqueous phase,if the latter is 1.9～5.6 mol/L.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By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent materials were discussed. The regularities and characteristic of energy bands of Gaq3 and its derivatives were also investigated. The results show that the electronic π-π* transitions in Gaq3 are localized on the quinolate ligands. The emission of Gaq3 is due to the electron transitions from a phenoxide donor to a pyridyl acceptor. Two possible electron transfer pathways are presented, one by carbon atoms, and the other via metal cation Ga3+. The derivatives of Gaq3 may possess high luminescence efficiency.
文摘The rate of batch extraction of gallium from alkaline aqueous solution was studied by adding 2-ethylhexanoic acid in organic phase containing 7-substituted-8-hydroxyquinoline(extractant N601), n-decanol and kerosene.The extraction of Ga can be considered as a pseudo-homogeneous first-order reac- tion.The neutralization and distribution of organic acid between phases during the extraction were studied. The effect of 2-ethylhexanoic acid on the protonation of N601 is insignificant.The extraction of HCl during the stripping of gallium is mainly dependent on the concentration of aqueous hydrochloric acid and the con- tent of N601.Under the given conditions of temperature and N601 content,the acidity of organic phase is a linear function of the concentration of carboxylic acid in organic phase and the concentration of hydrochloric acid in equilibrium aqueous phase,if the latter is 1.9～5.6 mol/L.
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.
