面向显示应用的钙钛矿量子点随机激光研究

Laser display is one of the most promising display technologies due to its dominating features such as super brightness, high contrast and rich in color. Laser Phosphor Display (LPD) is one of the low-cost routes to achieve the laser display. A crucial problem of LPD technology is impure red and green primary colors due to fluorescent phosphors. Random lasers have many advantages such as high brightness, narrow band width and low coherence. Perovskite quantum dots have the characteristics of high color purity, tunable spectra and high photoluminescence quantum yield, and they are promising materials to achieve the low threshold random lasers. In this project, perovskite quantum dot based red and green random lasers are proposed to replace the red and green phosphors. The main goals of this project include: (1) Develop the synthetic strategies and enhance the stability of the perovskite quantum dots; (2) Fabricate the perovskite quantum dot random laser devices and investigate their lasing properties theoretically and experimentally; (3) Assemble the random laser display prototype and explore its applications. This project involves cross-discipline scientific issues such as quantum dot synthesis, random laser fabrication, laser detection and display, and it will set a new track in the development of the display technology.

激光显示是显示技术的重要发展方向，激光荧光粉显示 (LPD) 是实现低成本激光显示的有效技术途径之一。目前，LPD 使用红、绿荧光粉作为红、绿基色光源，存在基色不纯的缺陷，不能充分发挥激光显示色域广的优势。随机激光具有半峰宽窄、亮度高、相干性低等优点，钙钛矿量子点是一类具有优异性能的发光材料，有望实现低阈值随机激光。本项目将钙钛矿量子点随机激光应用到显示中，提出使用钙钛矿量子点红、绿随机激光器实现红、绿基色的思路。主要研究内容包括：（1）发展钙钛矿量子点材料的制备技术，获得高稳定和发光波长可调的量子点；（2）研制钙钛矿量子点随机激光器件，获得可被蓝光激光二极管激发的低阈值、高品质因子随机激光；（3）研制随机激光色轮，组装显示样机，测试其显示性能。本项目首次提出将钙钛矿量子点随机激光应用于显示，项目的开展涉及到量子点合成、随机激光器制备、显示等多学科科学问题，将推动激光显示技术的发展。

激光显示技术是以激光作为光源的显示技术，具有色域覆盖率大、色饱和度高和易实现高分辨大屏幕显示等特点，具有巨大应用前景，激光显示的核心技术是连续激光光源。钙钛矿量子点具有量子产率高、发光波长可调、吸收截面大、缺陷少等优点，是一类优异的激光增益材料。针对激光显示应用，本项目使用原位制备技术，成功制备了具有优异光学性能和热学性能的MAPbX3 PQDs/PAN光学膜。使用该光学膜作为增益介质，我们实现了极低阈值、颜色可调、室温工作的钙钛矿量子点连续激光发射。所得到的绿光、红光和蓝光连续激光的阈值分别为15 W/cm2、24 W/cm2和58 W/cm2，品质因子分别为1200、910和1330。本报道的连续激光阈值比 CdSe 类量子点连续激光的阈值低一个数量级，为已报道溶液法制备胶体量子点的激光阈值最低值。此钙钛矿量子点膜还可以用于压力传感领域。针对激光显示应用，我们还使用向列相液晶和金纳米颗粒作为散射介质，成功制备了柔性聚合物薄膜随机激光器，该柔性随机激光器具有可拉伸、阈值可调、易集成等优点。在本项目支持下，申请人在Sci. China Mater., J. Phys. Chem. Lett., Opt. Mater. Express等国内外期刊上共发表学术论文5篇，申请中国发明专利6项，已授权2项，参加国内外学术会议6次，申请人于2020年12月晋升副高级职称。