Films of poly(9,9-dioctylfluorene)(PFO) are of great importance in fabricating light emitting diodes.In practice, theβ-phase of PFO is expected due to its high efficiency in the transport of charge carrier.To promote...Films of poly(9,9-dioctylfluorene)(PFO) are of great importance in fabricating light emitting diodes.In practice, theβ-phase of PFO is expected due to its high efficiency in the transport of charge carrier.To promote the formation of β-phase,PFO films are immersed and annealed in the mixture of solvent/nonsolvent.The effects of temperature, solvent/nonsolvent ratio, and annealing time are examined systematically.It is found that the fraction of β-phase can be highly improved by increasing the ratio of solvent/nonsolvent.The reconfiguration of PFO molecules for β-phase in annealing is generally finished in 10 min.The finding in this study demonstrates that solvent-assisted annealing offers a fast and economic approach for mass annealing.展开更多
Reactions between dislocations are investigated in two-dimensional colloidal crystals.It is found that,because of the conservation of total Burgers vectors,the kinetics of the reaction is dependent on the the symmetry...Reactions between dislocations are investigated in two-dimensional colloidal crystals.It is found that,because of the conservation of total Burgers vectors,the kinetics of the reaction is dependent on the the symmetry of the crystal lattice.Merging is possible only when the total Burgers vector of the reacting dislocations is in line with existing crystal lines.In non-merging reactions,the number of dislocations cannot be reduced but the interacting dislocations can exchange their Burgers vectors and migrate to different gliding lines.The changing of gliding lines promises additional annihilation in multi-dislocation reactions.The bonding of non-merging dislocations determines the configuration and the orientation of the grain boundaries.The findings in this study may shed new light on understanding of dislocations and have potential applications in fabrication of crystalline materials.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674235,11374218,and 21204058)the National Laboratory of Solid State Microstructures,China(Grant No.M30036)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions,China
文摘Films of poly(9,9-dioctylfluorene)(PFO) are of great importance in fabricating light emitting diodes.In practice, theβ-phase of PFO is expected due to its high efficiency in the transport of charge carrier.To promote the formation of β-phase,PFO films are immersed and annealed in the mixture of solvent/nonsolvent.The effects of temperature, solvent/nonsolvent ratio, and annealing time are examined systematically.It is found that the fraction of β-phase can be highly improved by increasing the ratio of solvent/nonsolvent.The reconfiguration of PFO molecules for β-phase in annealing is generally finished in 10 min.The finding in this study demonstrates that solvent-assisted annealing offers a fast and economic approach for mass annealing.
基金Supported by the National Natural Science Foundation of China(Grant No.11674235,11635002,and 11974255)。
文摘Reactions between dislocations are investigated in two-dimensional colloidal crystals.It is found that,because of the conservation of total Burgers vectors,the kinetics of the reaction is dependent on the the symmetry of the crystal lattice.Merging is possible only when the total Burgers vector of the reacting dislocations is in line with existing crystal lines.In non-merging reactions,the number of dislocations cannot be reduced but the interacting dislocations can exchange their Burgers vectors and migrate to different gliding lines.The changing of gliding lines promises additional annihilation in multi-dislocation reactions.The bonding of non-merging dislocations determines the configuration and the orientation of the grain boundaries.The findings in this study may shed new light on understanding of dislocations and have potential applications in fabrication of crystalline materials.
