Zhang Zhiyuan, Zhang Qi, Wei Xuanxuan, Xiao Zihan, Zhu Shan, Fu Shuai, Sun Huizhi, Florica Camelia, Peng Junbiao, Xia Ruidong
Key Laboratory for Organic Electronics & Information Displays (KLOEID), Jiangsu-Singapore Joint Research Center for Organic/Bio Electronics & Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210046, China.
KAUST Solar Center (KSC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39797-39806. doi: 10.1021/acsami.3c05515. Epub 2023 Aug 10.
Multiwavelength organic lasers have attracted considerable interest in recent years due to the cost efficiency, wide luminescence coverage, and simple processability of organics. In this work, by simply spin coating immiscible polymeric gain media in sequence, dual-wavelength (blue-green or blue-red) amplified spontaneous emission (ASE) was achieved in bilayer devices. The blue emission, water/alcohol-soluble conjugated polyelectrolyte, poly[(9,9-bis(3'-((,-dimethyl)--ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]dibromide (PFN-Br), was used as the bottom layer. The commercially available nonpolar solvent soluble polymer poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) and its blend with poly(3-hexylthiophene) (P3HT) were used as the top active layers offering green and red emission, respectively. This novel compact configuration, without interlayers between the two active layers, offers potential for developing various applications. The carefully selected top and bottom layer polymers not only meet the conditions of immiscibility and different emission wavelength range but also have a common absorption band in UV, which allows simultaneous blue-green or blue-red dual-color ASE behaviors observed in the bilayer devices under the same 390 nm laser excitation. By introducing two-dimension (2D) square distributed feedback (DFB) gratings with different periods (300 nm for blue, 330 nm for green, and 390 nm for red) as cavities, single mode blue-green ( = 245 μJ cm) and blue-red ( = 189 μJ cm) lasers were achieved by focusing the excitation laser spot on different 2D DFB gratings area. Furthermore, we found it possible to gain sufficient light confinement for red emission along its diagonal direction (Λ ∼424 nm), whereas the 2D DFB gratings offer feedback for blue emission from the 300 nm period along the rectangle direction. Therefore, both blue and red lasers were eventually achieved in the same PFN-Br/F8BT:P3HT bilayer device on the single 2D DFB gratings with a period of 300 nm in this work.
近年来，多波长有机激光器因其成本效益、宽发光覆盖范围和有机物简单的可加工性而备受关注。在这项工作中，通过简单地依次旋涂互不相溶的聚合物增益介质，在双层器件中实现了双波长（蓝绿色或蓝红色）放大自发辐射（ASE）。蓝色发射体，即水/醇溶性共轭聚电解质聚[(9,9-双(3'-((N,N-二甲基)-N-乙基铵)-丙基)-2,7-芴)-alt-2,7-(9,9-二辛基芴)]二溴化物（PFN-Br），被用作底层。市售的非极性溶剂可溶性聚合物聚(9,9-二辛基芴-共-苯并噻二唑)（F8BT）及其与聚(3-己基噻吩)（P3HT）的共混物分别被用作提供绿色和红色发射的顶层活性层。这种新颖的紧凑结构，在两个活性层之间没有中间层，为开发各种应用提供了潜力。精心选择的顶层和底层聚合物不仅满足互不相溶和不同发射波长范围的条件，而且在紫外光区有共同的吸收带，这使得在相同的390 nm激光激发下，在双层器件中观察到同时的蓝绿色或蓝红色双色ASE行为。通过引入具有不同周期（蓝色为300 nm，绿色为330 nm，红色为390 nm）的二维（2D）方形分布反馈（DFB）光栅作为腔，通过将激发激光光斑聚焦在不同的2D DFB光栅区域，实现了单模蓝绿色（ = 245 μJ cm）和蓝红色（ = 189 μJ cm）激光器。此外，我们发现有可能在红色发射沿其对角线方向（Λ ∼424 nm）获得足够的光限制，而2D DFB光栅为沿矩形方向的300 nm周期的蓝色发射提供反馈。因此，在这项工作中，在具有300 nm周期的单个2D DFB光栅上的同一PFN-Br/F8BT:P3HT双层器件中最终实现了蓝色和红色激光器。
