Optoelectronic Properties Of Organic Semiconductors And Crystal Laser Devices Applications Research

The organic single crystals have excited great interest as active building materials forelectronic and photonic devices. Compared to their inorganic counterparts, organicmaterials offer several advantages, such as high order molecular packing, and highchemical purity, and high stimulated emission cross section and self-waveguide emissionproperties, which are promising for laser active materials. The research of microcavitylasers and waveguides made of new type photoelectron materials will make a great advancein information, and also in military and industrial and communication. But we have alimited research in organic crystals. However, their use has brought significant advances inthe area of organic electronics，there are still critical issues that must be overcome forlarge-scale application of crystal in practice. To use organic crystal in high performancedevices and large-scale integrated circuits, it is critical to synthesize and align crystalsprecisely in the desired positions. We fabricated high quality organic crystal microcavityand achieved lasing. The researches of organic single crystal-based devices in our paper inthe following aspects:1.9,10-bis(3,5-difluorostyryl)anthracene (TFDSA) organic nanowires with highquality have been fabricated by the reprecipitation preparation method. The nanowireswere characterized by scanning electron microcopy (SEM)， transmission electronmicroscopy (TEM) and photoluminescence (PL) spectra et. al. The results show flatsurface of the nanowires with length of20-30um and width of400nm, strong greenfluorescence emission and typical strong waveguide behavior. As-prepared TFDSAnanowire is able to serve as single wire active optical waveguide due to propagating lighton the sub-wavelength scale. TFDSA can be used as candidates for potential nanoscalephotonic devices.2. Organic micro-crystals with rectangular shape were fabricated with self-assembled crystallization of microstructures in liquid phase. These microcrystals serve as opticalresonators for feedback, leading to a micro-cavity effect and a relatively low threshold oflaser oscillation. The observed lasing modes match well with Fabry-Pérot modes.3. Whispering-gallery mode resonators of OMSB laser array have been fabricatedwith the printing method. The only approach currently available for creating well alignedarrays of separate devices is manual selection and placement of individual organicnanowires; this process is prohibitive for producing a high density of device withreasonable throughput. This simple method enables the simultaneous synthesis andalignment and controlled positioning of single-crystal organic microdisks. Many crystalscan easily be crystallized of organic molecules, and these disks can be directly transferredto generate disk arrays by a direct printing process. The position of the disk on complexstructure is easy to adjust, because the mold is movable on the substrate. This process cancontrol individual crystal with desired orientations and specific positions. By change thepattern of the molds, we can get different pattern arrays. Printed organic crystal arrayscould potentially be used in all organic crystal integrated electronics for transparent,flexible, inexpensive, and large-area applications.