Controllable Construction And Photonic Research Of Organic Single/Multi-Level Low-Dimensional Structures

Organic semiconductor materials have been widely used in various optoelectronic devices due to the characteristics of designable molecular structure,adjustable physicochemical properties,high luminous efficiency,simple low-cost and large-area processing,etc.Compared with thin-film materials,organic micro-nano crystalline materials have less structural defects,higher purity,regular morphology,better stability,high mobility,and are more suitable for integrated high-performance optoelectronic micro-nano devices.With the higher requirements for miniaturization,integration and multi-functionalization of organic optoelectronic devices,crystalline materials with multi-level structures and functions are in great demand.However,there are still certain technical difficulties for the controllable construction of multi-level micro-nano structures with multiple functions,in terms of crystals' morphology and manipulation of optical signals.Therefore,in this thesis,to solve the two key issues,a series of controllable synthesis strategies have been formulated on the basis of adjusting molecular structure and self-assembly process.The growth mechanism and optical properties of these as-prepared organic crystalline materials are well explored.In addition,several functional organic micro-nano photonics devices are constructed based on the transmission and interaction behaviors of photons,which provides a certain theoretical and experimental basis for the future integrated multifunctional optoelectronic devices.The specific research contents are as follows:(1)Single structure with single component:The amphiphilic(E)-3-(4-(di-p-tolylamino)phenyl)-1-(4-fluoro-2-hydroxyphenyl)-2-propen-1-one(DTPHP)is synthesized by modifying the molecule with certain groups.Through the rapid solvent exchange method,spherical organic micro-nano structures with uniform size distribution were prepared,and the fluorescence spectrum showed obvious fine vibration peaks,which satisfies the characteristics of Whispering-Gallery-Mode(WGM)resonator.In addition,we figured out the optical dispersion relationship curve between ng and transmission wavelength(?)inside the DTPHP microspheres,and the value of the obtained ng ranges form 4.5 to 7.7,indicating that light and matter in the microsphere experience a strong interaction(2)Multi-level structure with single component:By changing the ratio of good and poor solvents,1,4-bis((E)-4-iodostyrene)-2,5-dimethoxybenzene(BIDB)molecules can controllably self-assemble into one-dimensional microrods and continuously grow into branched organic multi-level homogeneous micro-nano crystalline structure.The angle between the trunk and dendrites is fixed at 75°.Using detection methods like TEM and simulation calculations,the sequential self-assembly of this branch-like micro-nano structure is derived from the resulted selected growth due to low lattice mismatch rate(6.1%)between the(020)and(110)crystal plane.Taking advantage of the asymmetric optical waveguide characteristics of this multi-level homogeneous structure,we constructed a simple optical switch model with an ON/OFF of 10.5.(3)Multi-level structure with multi-components:By making use of 1,4-phenylene-bis(3-(2-methoxypyridin-6-yl)acrylonitrile)(MPY)and polymorphic 2,5,8,11-tetra-tert-butylperylene(TBPe),multi-level heterogeneous micro-nano structures in longitudinal and lateral growth modes were fabricated,with MPY nanowires as the backbone,TBPe?-phase microrods and ?-phase microplate crystals as dendrites respectively.The different growth direction of polymorphic TBPe in heterostructures is achieved by controlling the growth rate of crystals.In the longitudinal growth of MPY/?-TBPe heterostructures,lattice matching plays a dominant role,while the driving force of lateral growth of MPY/?-TBPe heterostructures is the principle of energy balance.Based on the transfer behavior of light in the heterostructures with multiple outputs,optical logic gate models of "1 00"," 1 1 0" and "111" were obtained,providing practical examples for the application of organic crystalline materials in multifunctional micro devices.