【作者】 王艳辉；

【导师】 宋俊峰； 冯晶；

【作者基本信息】 吉林大学 ， 微电子学与固体电子学， 2015， 博士

【摘要】 目前，有机电致发光器件（OLEDs）由于具有质量轻、低成本、低功耗、材料多样的优点而成为研究的热点。OLEDs在手机等电子产品中已经有所应用，但是还不能实现大规模的应用。有机电致发光器件和有机太阳能电池技术中还存在着一些需要解决的问题，如顶发射有机电致发光器件在平板显示当中的光谱角度依赖问题和有机太阳能电池效率低等问题。本论文的工作主要是基于顶发射有机电致发光器件（TOLEDs）的光谱视角依赖方面以及有机太阳能电池(OSCs)光电转换效率不足的问题开展研究。通过制备基于微结构的器件，来解决顶发射有机电致发光器件的光谱视角依赖问题，提高了有机太阳能电池的效率。此外，我们还在曲面上进行了顶发射有机电致发光器件的制备，成功实现全方向的光出射。取得的研究成果主要包括以下几个方面：（1）在红光和蓝光顶发射有机电致发光器件中，通过引入周期性光栅微结构，解决了红光和蓝光顶发射有机电致发光器件中微腔效应带来的光谱窄化和光谱视角依赖的问题。采用这种方法，得到了周期性变化的微腔腔长，使微腔的谐振波长范围变宽。最终，具有光栅微结构的顶发射器件实现了朗伯体发射，同时解决了不同的观察角度颜色变化的问题。此外，有无光栅微结构器件的发光亮度和效率基本一致。（2）利用曲面透镜作衬底，制备顶发射有机电致发光器件。曲面的发光器件可以实现全方向的光出射，有效降低了发光强度随观察角度而很快衰减的问题。在垂直于器件发光方向的位置，依然可以观察到光的出射。为有机电致发光器件在全方向固态照明的应用，提供了新的技术方案。（3）制备了基于周期性微结构的有机太阳能电池，增强了有机太阳能电池的光吸收，从而提高器件的光电转化效率。实验结果表明，周期性的微结构金属电极表面提高了在材料内的入射光程，更多的光被限制在材料内。此外，使用半透明Au作为阳极，Ca/Ag作为阴极，提高了电荷的收集。常见的Al做阴极的平板太阳能电池器件能量转化效率只有0.61%，而Au作阳极，低功函数Ca/Ag做阴极的微结构太阳能电池，能量转化效率达到1.4%。和常用来做阳极的稀缺的ITO铟材料相比，采用周期性的微结构的Au薄膜阳极有望取代ITO，实现成本低廉、高性能的有机太阳能电池。更多还原

【Abstract】 Organic light-emitting devices (OLEDs) have been attracting great attentiondue to their advantages in light weight, low cost, low power consumption,abundant materials. At present, OLEDs have been used into a mobile phone and afew other electronic products. However, it can not achieve a large scale application.There are a few questions to be solved, such as viewing-angle dependencecharacteristics of top-emitting organic light-emitting diodes(TOLEDs) and lowpower conversion efficiency in organic solar cells (OSCs). In this thesis, muchresearch has been done on viewing-angle dependence characteristics of TOLEDsand power conversion efficiency in OSCs. The microstructures have been fabricatedand applied in TOLEDs to eliminate the angular dependence emission of TOLEDs. Atthe same time, the microstructures have also been applied in OSCs to improve thepower conversion efficiency. Moreover, we have also fabricated TOLEDs on a curvedsurface to achieve omnidirectional light emission. The results include the followingaspects:(1) An effective way has been demonstrated that resolve viewing-anglecharacteristics and narrow spectra owing to microcavity effect in red and blueemission TOLEDs by introducing periodic microstructures. From this approach,periodically changed cavity length can be achieved and the range of the resonantwavelength in these devices can be broadened. As a result, TOLEDs with microstructures exhibit a quasi-Lambertian emission pattern and have no color shiftat different viewing angles. In addition, we can almost observe the uniformluminance and efficiency in TOLEDs with and without microstructures.(2) We have fabricated a TOLED on curved surface using a photopolymer lensas substrate and demonstrated that omnidirectional emission from TOLEDs on acurved surface. Compared to the planar TOLEDs, the emission intensities ofTOLEDs on curved surface show an obviously slower decrease with the increasingof the observation angle and can be observed at90°off the surface normal. Thisapproach is a new alternative and important for the applications of TOLEDs insolid-state light.(3) A periodic corrugation was introduced into the device structure, which leadsto an enhanced light absorption in the OSCs by elongating the optical path of theincident light inside the absorber material. Moreover, the indium-tin-oxide-free OSCshave been fabricated using a semitransparent Au film as anode. A comparative studybetween the OSCs with different metal cathodes shows that formation of an idealohmic contact at low-workfunction Ca and the organic interface reduces seriesresistance and increases the carrier collection. The highest power conversionefficiency of optimal OSC with a corrugated Au anode and Ca/Ag cathode is1.4%,which is significantly improved in contrast to0.61%for the OSC with a planar Alcathode. Because of the shortage of indium, the indium–tin-oxide-free OSCs havebeen fabricated using Au film as anode and a periodic corrugation was introduced intothe device structure, which leads to a low cost and an enhanced power conversion efficiency in the OSCs.更多还原