Different C_(60) crystals were synthesized by precipitation from a mixture of the good solvent m-xylene and the poor solvent isopropyl alcohol.The samples were characterized by scanning electron microscopy(SEM),Raman ...Different C_(60) crystals were synthesized by precipitation from a mixture of the good solvent m-xylene and the poor solvent isopropyl alcohol.The samples were characterized by scanning electron microscopy(SEM),Raman spectroscopy,thermogravimetric analysis,and high resolution transmission electron microscope(HRTEM).We found that the morphologies and sizes of the samples could be controlled by adjusting the volume ratio between the good and poor solvents.Especially,an unexpected short flower column-like crystal was synthesized at low ratios(from 1:6 to 1:12).Room temperature photoluminescence(PL)and HRTEM studies of the C_(60) crystal samples reveal that the PL efficiency of the crystals decreases with increasing crystalline order and that the disordered C_(60) crystals synthesized at the ratio of 1:2 show 10 times higher PL efficiency than that of pristine C_(60).The mechanism of the growth process of these C_(60) crystals was also studied by replacing the good solvents m-xylene with toluene and mesitylene.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504269 and 11504267)Tianjin Natural Science Foundation(Grant No.20JCQNJC00660)the Program for Innovative Research in University of Tianjin(Grant No.TD13-5077).
文摘Different C_(60) crystals were synthesized by precipitation from a mixture of the good solvent m-xylene and the poor solvent isopropyl alcohol.The samples were characterized by scanning electron microscopy(SEM),Raman spectroscopy,thermogravimetric analysis,and high resolution transmission electron microscope(HRTEM).We found that the morphologies and sizes of the samples could be controlled by adjusting the volume ratio between the good and poor solvents.Especially,an unexpected short flower column-like crystal was synthesized at low ratios(from 1:6 to 1:12).Room temperature photoluminescence(PL)and HRTEM studies of the C_(60) crystal samples reveal that the PL efficiency of the crystals decreases with increasing crystalline order and that the disordered C_(60) crystals synthesized at the ratio of 1:2 show 10 times higher PL efficiency than that of pristine C_(60).The mechanism of the growth process of these C_(60) crystals was also studied by replacing the good solvents m-xylene with toluene and mesitylene.
