高性能有机/钙钛矿多层膜多波长发射激光器件研究

Organic/polymer semiconductor laser has wide potential application in optical communication, laser display, medicine and environment monitor due to its easy fabrication, low cost, solution prossionable and flexible. We propose a multi-disciplinary strategy, including material designing for target functions organic gain media, procession exploring for perovskite laser film, and device fabrication with distributed feedback (DFB) grating combining first and second order, to develop solution processable optically pumped low threshold, high gain, high stability organic laser and perovskite laser device. Based on these results, we will explore approach to achieve organic/perovskite multi-layer laser for multi-wavelengths lasing. Different functional side chain will be induced to improve the solubility and stability of the organic materials. In order to reduce triplet absorption and to achieve high gain, a novel scientific idea of building-up binary bulk heterostructure gain media for ultrafast inter chain energy transfer will be explored. A controllable procession for perovskite film fabrication will be developed to reduce absorption in visible wavelength range. A novel device configuration consisting of interlayer below and above gain media is proposed to increase optical confinement, to reduce interface loss and to improve charge transfer behaviour (for electrically pumped device). New distributed feedback grating system with combination of first and second order gratings will be designed. Finally, organic/perovskite multi-layer laser for multi-wavelength lasing will be fabricated. Meanwhile, a systemic study will be carried out to understand the correlation between chemical structure of binary gain media, aggregation, morphology and device structure (such as thickness of interlayer and grating parameter) and gain properties including enhancement, loss, exciton quench. Furthermore, the effect of pulse length and repeat rate of the optical pumping source on the laser threshold will be investigated in detail. The influence of the electrical field and current on the exciton under an electrically pumped device configuration will be studied to explore the possible path toward electrically pumped laser.

本项目拟通过设计合成高性能有机激光增益材料，探索低阈值钙钛矿激光薄膜制备工艺，采用一级、二级光栅结合的器件结构获得可溶液制备的低阈值、高增益单层器件，进而实现有机/钙钛矿多层膜多波长发射激光器件。研究包括在有机发光材料合成中引入功能侧链或官能团改善其溶解性、稳定性等；通过材料搭配、比例优化，建立二元共混体异质结激光增益薄膜体系，实现给体到受体的超快激子能量传递，降低或避免三线态激子和极化子对光子的吸收；研究钙钛矿薄膜的可控制备工艺，降低其对可见光的吸收损耗；引入界面材料构筑对称光波导增加光子反馈；设计一级、二级光栅结构，优化光栅参数；研究有机/钙钛矿多层膜制备工艺、降低界面损耗；最终实现光泵浦有机/钙钛矿多层膜多光谱发射的激光器件。在此基础上研究光泵浦源脉宽和重复频率对器件激光产生阈值的影响，及电泵浦器件结构中电场及电流对光子的各种损耗机制，探索实现连续光泵浦或电泵浦器件的可能性。

本项目拟通过设计开发高性能有机激光增益材料，探索低阈值钙钛矿激光薄膜制备工艺，采用一级、二级光栅结合的器件结构获得可溶液制备的低阈值、高增益有机和钙钛矿激光单层器件，在此基础上，通过材料选择搭配、多层膜制备工艺优化和器件结构优化，实现有机/有机、有机/钙钛矿多层膜多波长发射光泵浦激光器件。进而在获得低阈值ASE材料的基础上，研究探索实现电泵浦器件的可行性方案。具体研究内容包括在有机发光材料合成中引入功能侧链或官能团降低荧光萃灭、改善其溶解性、稳定性等；对单一有机材料利用链取向技术，提高材料定向折射率、降低阈值；通过材料搭配、比例优化，建立二元共混体异质结激光增益薄膜体系，实现给体到受体的超快激子能量传递，降低有机激光阈值；研究钙钛矿薄膜的可控制备工艺，改善薄膜平整度，钝化表面缺陷，降低其对可见光的吸收及散射损耗；引入界面材料构筑对称光波导增加光子反馈，降低界面损耗，以及在电泵浦器件中提高载流子注入；针对所用光增益活性材料设计制备一级、二级光栅，优化光栅参数；并对单层及多层膜中的超快光子学过程、各种多层膜结构中光振荡膜式分布、光损耗机制等做了深入系统分析。项目还重点研究了钝化钙钛矿薄膜表面缺陷的方法和机理，这一系列机理相关的研究为构建电泵浦有机激光器件提供了科学依据。项目已经完成预期目标，利用溶液制备的有机多层膜实现了单一光源泵浦下多光谱激光输出，特别是有机/钙钛矿双层膜与泵浦激光光源结合实现红绿蓝三基色激光ASE输出的最简器件结构，展示了GaN激光泵浦有机多层膜实现低成本、高分辨、小型化彩色激光显示的可能性。.在项目基金的支持下，项目已经正式发表SCI科学论文20余篇，包括多篇高影响因子期刊文章。申请发明专利7项，授权5项。此外，项目还有三篇文章提交审稿，有些工作正在整理，有两篇文章和两项专利将在近期完成。