基于衬底图形化与链取向技术实现平面光波导  

Design of planar waveguide based on patterning substrate and oriented polymer film

作　　者：方月婷 易建鹏 陈锦山[1] 汪洪杰[1] 池浪 夏瑞东[1] 

机构地区：[1]南京邮电大学信息材料与纳米技术研究院,有机电子与信息显示国家重点实验室培育基地,江苏省有机光电材料协同创新中心,南京210023

出　　处：《物理学报》2016年第5期204-209,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准:61376023,61136003);国家重点基础研究发展计划(批准号:2015CB932203);南京邮电大学引进人才启动基金(批准号:NY212013,NY212034);江苏高校优势学科建设工程(PAPD)资助的课题~~

摘　　要：采用喷墨打印的方法对衬底进行图形化,结合链取向技术,实现聚合物混合体poly(9,9-dioctylfluoreneco-benzothiadiazole)(F8BT,主体)和red F(客体)在指定区域链取向.利用链取向区域内外的折射率差异,设计出了各种宽度的薄膜光波导,使光信号在链取向区域传播.同时,这一共混体系中主体的荧光光谱与客体的吸收光谱区域重叠,可以使有效的能量传递发生,利用主体向客体的能量传递机理,使链取向处理后的聚合物混合体实现了红光发射.Semiconducting conjugated polymersused for light emitting devices（LEDs）, lasers and amplifiers have received considerable attention due to their low cost and easy fabrication through spin-coating and photochemical processing. A promising material for LED and laser applications is poly（9, 9-dioctylfluorene-co-benzothiadiazole）（F8BT）. F8BT has a low stimulated emission threshold and exhibits a large net optical gain at 570 nm. It also shows liquid crystallinity and can be readily aligned into a monodomain by using an alignment layer, polyimide（PI）. Oriented film of F8BT exhibits that its charge carrier mobility is increased by more than one order of magnitude compared with isotropic film. The refractive index of the material is also greatly affected by the orientation of the polymer chain. Furthermore, it has been reported that low threshold laser can be achieved by blending P3HT or red-F solution into F8BT via energy transfer.Here we report a planar waveguide structure obtained via patterning chain oriented area on F8BT ： red-F（9 ： 1）blend polymer film. The blend solution is obtained by mixing the F8BT solution with red-F solution（with the same concentration, 20 mg/m L in toluene） with a ratio of 9 ： 1. The designed waveguide patterns are obtained by inkjetprinting the PI solution onto the pre-cleaned quartz substrates. Thin films（150–200 nm thick） of F8BT ： red F are deposited onto PI by spin coating（2000 rpm）. The chain alignment treatment is performed by the following procedure：the films are kept in N_2 at 265℃ for 2 min, then they are cooled down to 235℃ at a rate of 1℃ / min, finally they are cooled down to room temperature sharply. The PI contacted area on the film becomes anisotropic, while the area without PI keeps isotropic. The refractive index parallel（perpendicular） to the chain direction is significantly increased（reduced） in the PI contacted area compared with outside the PI area. Therefore, the waveguide confinement could be achieved without

关 键 词：链取向 衬底图形化 薄膜光波导 发光聚合物 

分 类 号：TN252[电子电信—物理电子学]