Solvent Vapor Crystallization (SVC) for the selective growth of vertical 1D wire of highly conjugated functional molecules
소속 :
연사 : Prof. Hee Cheul Choi ( Postech )
일시 : 2013-04-25 16:30 ~
장소 : 500동 목암홀
일 시 : 2013년 4월 25일, 4:30 PM
장 소 : 500동 목암홀
-Abstract-
During the last two decades, remarkable advancement in physical science has been achieved by the discovery of quantum size effect (QSE) that grants new optical, electrical and chemical properties upon the reduction of sizes of bulk materials into low-dimensional particles of which energy states closely mimic those at molecular level. Similar achievements with comparable degree of importance are also plausible by structuring individual ensemble molecules into specific geometrical structures in various dimensions through self-assembly or self-crystallization. Among several synthetic methodologies resulting in such self-crystallization of highly conjugated molecules, I will introduce two solution-based methods: 1) drop-drying method and 2) solvent vapor crystallization (SVC) method. The drop-drying method is a very simple and fast process to obtain 1D or 2D structures of conjugated molecules in a solvated form. The examples include C60 molecules self-crystallized into 0D dots, 1D wires and 2D disks by simply dropping and drying several aliquots of C60 solution on a solid substrate. The determinant of the final geometry turns out to be solvent, of which geometry eventually guides C60 molecules to self-crystallize into specific geometries. One drawback of drop-drying process is that most of resulting products are lying on a substrate, which limits its versatility especially when one needs to self-crystallize target molecules into vertical direction. Recently, we have succeeded in vertical self-crystallization of C60 molecules by SVC method of which experimental process resembles that of solvent vapor annealing (SVA) process. More details about the growth mechanism by SVC process and potential applications will be discussed.
장 소 : 500동 목암홀
-Abstract-
During the last two decades, remarkable advancement in physical science has been achieved by the discovery of quantum size effect (QSE) that grants new optical, electrical and chemical properties upon the reduction of sizes of bulk materials into low-dimensional particles of which energy states closely mimic those at molecular level. Similar achievements with comparable degree of importance are also plausible by structuring individual ensemble molecules into specific geometrical structures in various dimensions through self-assembly or self-crystallization. Among several synthetic methodologies resulting in such self-crystallization of highly conjugated molecules, I will introduce two solution-based methods: 1) drop-drying method and 2) solvent vapor crystallization (SVC) method. The drop-drying method is a very simple and fast process to obtain 1D or 2D structures of conjugated molecules in a solvated form. The examples include C60 molecules self-crystallized into 0D dots, 1D wires and 2D disks by simply dropping and drying several aliquots of C60 solution on a solid substrate. The determinant of the final geometry turns out to be solvent, of which geometry eventually guides C60 molecules to self-crystallize into specific geometries. One drawback of drop-drying process is that most of resulting products are lying on a substrate, which limits its versatility especially when one needs to self-crystallize target molecules into vertical direction. Recently, we have succeeded in vertical self-crystallization of C60 molecules by SVC method of which experimental process resembles that of solvent vapor annealing (SVA) process. More details about the growth mechanism by SVC process and potential applications will be discussed.
