电泵浦有机准晶光子晶体激光器的制备及性能研究

发布时间：2018-09-02 06:39

【摘要】：信息技术的发展使人们对作为信息输出终端的显示技术提出了更高的要求。与其它显示技术相比,有机电致发光器件具有体积小、功耗低、寿命长、视角广、分辨率高、响应快、重量轻、大面积可柔性显示等优点,成为21世纪光电信息技术发展中备受瞩目的前沿课题之一,并得到广泛而深入的研究。自从Tessler采用聚对苯撑乙炔(PPV)作为增益介质,分布布拉格反射镜(DBR)作为谐振腔得到激射信号以来,在各类微结构包括F-P腔、微环、波导和光子晶体结构中均已实现了光泵浦激射。由于有机聚合物载流子迁移率较低,在基于波导和DBR结构的光电器件薄膜中将造成较大的光学损耗,而光子晶体微腔因其具有光子禁带和光子局域特性被认为是实现有机电泵浦激光器的最佳微结构之一。本论文中,我们利用有机共轭聚合物的电致发光特性、光子晶体微腔对光子的局域与选模特性、微腔缺陷自身在与光子晶体平面垂直方向上的波导特性,以及上下表面膜系的反射特性,制备了具有增益介质、谐振腔、电泵浦的可见光波段输出的有机半导体光子晶体激光器,并实现了单点集成的谐振输出。我们选用具有优良发光特性的有机共轭聚合物MEH-PPV作为发光薄膜,在以ITO玻璃作为阳极,Al作为阴极的三明治结构中实现了有机电致发光,发光峰位于530-700nm,半高宽约为100nm,最高峰位于590nm。根扔MEH-PPV的电致发光谱,我们采用时域有限差分法设计一种9孔缺陷的二维平板8重准周期光子晶体微腔。通过优化包括晶格常数、孔径、缺陷分布等结构参数,在低折射率对比度的有机光子晶体中实现了低价带隙的打开和拓宽,并在微腔中获得了品质因数高达1212的缺陷模。该缺陷模位于597nm,与MEH-PPV的电致发光光谱吻合。根据优化后的微结构参数,我们用聚焦离子束刻蚀法将准晶微腔结构加工在MEH-PPV聚合物薄膜上,利用其与阴阳极组成的反射谐振腔,成功制备出具有激射效应的有机电泵浦激光器。该激光器的激射峰位于607nm,半高宽0.5nm,激射阈值电流约0.8mA。这一研究工作为后续制备可见光波段双波长输出的电泵浦有机光子晶体激光器,以及未来研制可控紧凑型三基色光源奠定了坚实的基础。
[Abstract]:The development of information technology makes the display technology as the terminal of information output more demanding. Compared with other display technologies, organic electroluminescent devices have the advantages of small volume, low power consumption, long life, wide angle of view, high resolution, fast response, light weight, flexible display in large area and so on. It has become one of the leading topics in the development of photoelectric information technology in the 21st century, and has been extensively and deeply studied. Since Tessler uses poly (p-phenylene) acetylene (PPV) as gain medium and distributed Bragg reflector (DBR) as resonator to obtain the stimulated signal, optical pumping has been realized in all kinds of microstructures, including F-P cavity, microloop, waveguide and photonic crystal structure. Because of the low carrier mobility of organic polymer, the optical loss will be caused in the thin films of optoelectronic devices based on waveguide and DBR structure. Because of its photonic bandgap and photonic localization, photonic crystal microcavity is considered to be one of the best microstructures to realize electromechanical pumped lasers. In this thesis, we use the electroluminescent properties of organic conjugated polymers, the localization and mode selection of photonic crystal microcavities, and the waveguide characteristics of microcavity defects in the perpendicular direction to the plane of photonic crystals. An organic semiconductor photonic crystal laser with gain medium, resonant cavity and electrically pumped visible light band output is fabricated by the reflection characteristics of the upper and lower surface film system, and the single point integrated resonant output is realized. Organic conjugated polymer (MEH-PPV) with excellent luminescence properties was selected as the luminescent film. Organic electroluminescence was realized in a sandwich structure with ITO glass as anode and Al as cathode. The luminescence peak was 530-700 nm, the half-maximum width was 100nm, and the peak was 590nmm. Based on the electroluminescence spectra of MEH-PPV, a 2-D planar 8-fold quasi-periodic photonic crystal microcavity with a defect of 9 holes is designed by using the finite-difference time-domain method (FDTD). By optimizing the structure parameters including lattice constant, aperture and defect distribution, the low valence band gap is opened and widened in the low refractive index contrast organic photonic crystal, and the defect mode with a quality factor of up to 1212 is obtained in the microcavity. The defect mode is located at 597 nm and coincides with the electroluminescence spectra of MEH-PPV. According to the optimized microstructure parameters, the quasicrystalline microcavity structure was fabricated on the MEH-PPV polymer film by focused ion beam etching method, and the reflection resonator composed of the cathode and the cathode was used to fabricate the quasicrystalline microcavity. An electromechanical pumped laser with excitatory effect has been successfully fabricated. The laser has a peak of 607 nm, a half maximum width of 0.5 nm and a threshold current of 0.8 Ma. This work has laid a solid foundation for the subsequent fabrication of electrically pumped organic photonic crystal lasers with two wavelengths of visible light and the development of controllable compact trichromatic light sources in the future.
【学位授予单位】：中央民族大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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