Effect Of Structures On The Energy Transfer In Organic Crystals

Due to the high mobility and excellent amplified spontaneous emissionproperties of organic crystals, it has received extensive attention of people. At thesame time, the good thermodynamic stability and high ordered structure of organiccrystals are also good models to study some properties of materials. Organic crystalshave been more and more applied in organic crystal field-effect transistors, organiclight-emitting devices and organic laser, etc. But the contradiction between highmobility and high luminous effciency of organic crystal makes it restricted in theapplications of light-emitting devices and electric pump laser. We hope to solve thiscontradiction by doping and ASE(aggregation induced emission), and realize theunity of carrier mobility and high luminous efficiency.We chose anthracene as the main material, and tetracene as the object material, toprepare doped crystals by physical vapor transport (PVT) method. Because of theexistence of energy transfer in the doping system, the energy can transfer fromanthracene to tetracene, fluorescence quenching of gathering are restricted by energytransfer,and at the same time, the color of the doped crystals are tunable. It improvedthe luminous efficiency of doped crystal greatly. In our research, we found that theamount of object material in my doping system is extremely lower than the dopingsystem which DSB as the main material, and tetracene, pentacene as the objectmaterials, when achieving the same level of energy transfer efficiency. Throughfurther research, we found that the orientation of molecular dipole in doped crystals has a significant impact to the energy transfer. Our research can provide a theoreticalbasis for option of the subject and object materials in energy transfer systems in thefuture.We also hope that by further increase conjugated degree of AIE molecules toimprove the photoelectric properties of crystals. We designed and synthesized severalkinds of molecules on the basis of DPDSB, and investigated the light physicalproperties and crystal structures of the molecules, then we compared them with theDPDSB molecules. We find that our new synthetic molecules still have AIE properties,and the crystal structures also have many similarities with DPDSB. So we realized thepurpose of increase the conjugate. Further more, we hope to get high quality, lamellarcrystals to test the carrier transfer properties.