Preparation And Properties Of Electrically Charged Organic Quasicrystal Photonic Crystal

With the development of information technology, it has demanded for the more effective output terminal display. Compared with other display technologies, organic electroluminescent devices have many advantages, such as small size, low power consumption, long life, wide viewing angle, high resolution, fast response, light weight, large area flexible display, thus making organic light-emitting devices to be one of the important research topics in the 21 st-century.Since Tessler achieved the lasing by utilizing Poly-Phenylene Vinylene (PPV) as the gain medium and Distributed Bragg Reflector (DBR) as the resonator, optically pumped lasing has been realized in various micro-structures, including F-P cavities, micro-rings, waveguides and photonic crystal structures. For the DBR and waveguides structures may induce a greater optical loss in polymer films due to the low carrier mobility, photonic crystals have become one of the best candidate structures to achieve the electrical pumped lasing.In this thesis, we fabricate an electrical pumped sandwiched quasicrystal organic semiconductor laser and achieve the electrical pumped lasing based on the electroluminescence of conjugated polymers, photon localization and mode-selection in photonic crystal microcavity, waveguide properties of defect microcavity, and reflection between the cathode and anode. In fabrication of electrically pumping emitting devices, we select Indium Tin Oxide (ITO) glass as the substrate and wet etch ITO into an anode bar on the glass. MEH-PPV powder is diluted in the mixed solution of chloroform and tetrahydrofuranand, and then the solution is spin-coated evenly on the top of ITO substrate. The electroluminescence (EL) spectrum of MEH-PPV covers from 530 nm to 700nm with a FWHM 100 nm, and the peak located at 590nm. According to the EL spectrum, we design a 9-hole-missing quasicrystal microcavity slab based on finite-difference time-domain (FDTD) method. By optimizing the parameters of microstructure, like the lattice constant, hole radius and location, we achieve the high-Q defect-mode in low refractive index contrast, which is corresponding to the EL spectrum of MEH-PPV. According to the simulation, we adopt FIB etching system as a micro-and nano-machining tool to transfer the designed pattern onto the MEH-PPV film. Then, by electrically pumping, the lasing action is observed at 607 nm with a FWHM of 0.5nm. The threshold current of lasing is about 0.8mA.These results lay the solid foundation for preparation of electrically pumped organic photonic crystal laser in the visible dual wavelength and the future applications of the integrated tri-color displayers.