Micro-LED全彩显示中量子点膜层制备及光转换效率优化  

Synthesis and Conversion Efficiency Optimization of Quantum Dots Layer for Full-color Micro-LED Display

作　　者：卢子元 庄永漳 仉旭 王涛 谭毅 王倩静 张晓东[2,3] 蔡勇[2,3] 张宝顺[2,3] 张晶[1] LU Zi-yuan;CHONG Wing-cheung;ZHANG Xu;WANG Tao;TAN Yi;WANG Qian-jing;ZHANG Xiao-dong;CAI Yong;ZHANG Bao-shun;ZHANG Jing(School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun 130022,China;Key Laboratory of Multifunctional Nanomaterials and Smart Systems,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]中国科学院苏州纳米技术与纳米仿生研究所纳米加工平台,江苏苏州215123 [3]中国科学技术大学纳米技术与纳米仿生学院,安徽合肥230026

出　　处：《发光学报》2022年第3期421-429,共9页Chinese Journal of Luminescence

基　　金：国家自然科学基金(U1830112);江苏省自然科学基金(BK20191195)资助项目。

摘　　要：将表面配体改性的CdSe/ZnS量子点(Quantum dots)和光刻胶混合,进而采用光刻工艺在InGaN/GaN蓝光Micro-LED上实现了最小尺寸为3μm的高分辨率、高光效的量子点颜色转换膜层。同时系统研究了不同厚度和混合比例的量子点膜层的吸收/发射光谱及光致发光量子产率(PLQY)。为优化光转换效率,量子点膜层中加入了TiO_(2)散射粒子以提高蓝光的吸收效率。更进一步地,经过设计引入分布式布拉格反射镜(DBR),使得未被吸收的蓝光光子回弹到量子点转换膜层,这不仅提升了蓝光吸收效率,也增强了转换色彩的饱和度。同时采用了热激发方式来提升量子点的光致发光量子产率。为得到更高的显示对比度和色彩饱和度,引入黑色光阻矩阵来削弱临近图形之间的颜色串扰。实验结果表明,该量子点膜层可以用光刻技术实现高分辨率、高光效的颜色转换图层,为单片全彩化Micro-LED显示的发展提供了新颖可靠的技术路线。In this paper,colloidal CdSe/ZnS quantum dots(QDs)with modified ligands are dispersed in photoresist and then patterned on blue InGaN/GaN Micro-LED by lithography process,demonstrating a high-resolution and highly efficient color conversion layer with critical dimension of 3μm.The absorption/emission spectrum and photoluminescence quantum yield(PLQY)of the QDs color conversion layer(CCL)with different thickness and mixing ratio are systematically studied.To improve the conversion efficiency,TiO_(2) scattering particles are diffused into the QDs CCL to enhance the blue light absorption.Moreover,a tailored distributed Bragg reflector(DBR)is introduced to make the unabsorbed blue photons bounce back to the QDs CCL,which not only amplifies the blue light absorption but also strengthens the saturation of the converted colors.The PLQY of the QDs CCL is even increased after appropriate hard baking.Black matrix material is applied to suppress the light crosstalk among neighboring pixels,thus higher contrast and color saturation are obtained.The promising experimental results prove that the QDs photoresist is feasible to construct a high-resolution and highly efficient color conversion layer by lithography process,paving a novel and reliable pathway to monolithic full-color Micro-LED displays.

关 键 词：Micro-LED 量子点 分布式布拉格反射镜(DBR) 颜色转换 散射粒子 

分 类 号：O482.31[理学—固体物理]