喷墨打印量子点薄膜:墨水溶剂的选择策略  

Inkjet Printing Quantum Dot Films:Solvent Selection Strategies for Jetting Inks

作　　者：欧家琦 彭曾一 王俊杰[1] 李丹阳 宋家宁 彭俊彪[1] OU Jiaqi;PENG Zengyi;WANG Junjie;LI Danyang;SONG Jianing;PENG Junbiao(State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学发光材料与器件国家重点实验室,广东广州510641

出　　处：《发光学报》2023年第12期2085-2097,共13页Chinese Journal of Luminescence

基　　金：广东省重点研发计划(2022B0303010001);国家重点研发计划(2022YFB3603103);国家自然科学基金(62074059)。

摘　　要：喷墨打印制备的量子点(Quantum dots,QDs)薄膜形貌对多层发光器件的性能影响显著(如量子点发光二极管),其中咖啡环与拱状形貌是典型的薄膜均匀性问题,通过液滴调控实现高质量QDs薄膜是发展量子点电致发光显示的关键。研究工作表明,通过溶剂实施的墨水调控被证明是改变沉积薄膜形貌的有效手段。然而,优化出可消除咖啡环或拱状形貌的墨水流变参数往往需要大量耗时的实验,墨水配制筛选效率低。本研究基于薄膜形貌分析结合机器学习方法,试图将溶剂流变参数与喷墨打印QDs薄膜形貌直接联系起来,并以红光QDs为溶质,以烷烃或直链酯类为溶剂,研究发现通常使用的一元溶剂和二元溶剂体系中,所使用溶剂的沸点比表面张力或粘度参数对薄膜沉积形貌的影响更加显著,在二元溶剂中薄膜形貌与沸点较高的溶剂组分密切相关。为得到厚度均匀的平整薄膜,建议一元溶剂墨水体系的溶剂或二元溶剂墨水体系中较高沸点的溶剂的沸点范围为250~265℃。The morphology of quantum dots(QDs)films fabricated by inkjet printing makes a marked impact on the performance of multi-layer photoelectronic devices,such as quantum dot light emitting diodes,where coffee-ring and bulge phenomena behave as the typical poor morphology types.Realizing high-quality QDs films through droplet modulation is key to the development of QDs electroluminescent displays.Ink engineering has been proven effective in adjusting the film morphology.However,a well-tailored ink with precise rheological properties to eliminate coffee ring or bulge requires multiple time-consuming experimental attempts,resulting in lower working efficiency.In this work,we sought to directly bridge the gap between the rheological properties of solvents and the profiles of inkjetprinted QDs films with post-mortem film analysis and machine learning methods adopted for mutual proof.With red QDs as the solutes,and alkanes or chain esters as solvents,work on unitary-solvent and binary-solvent ink systems was investigated to find out that generally,the boiling point of the used solvent displayed significant importance higher than that of surface tension or viscosity in both unitary and binary systems.Specifically,the film profile was closely related to the solvent with a higher boiling point in binary systems and uniform films were revealed.A boiling point range of 250-265℃for the solvent in the unitary-solvent ink system or for the higher-boiling-point solvent in the binary-solvent ink systems can promisingly result in uniform films after drying.

关 键 词：量子点墨水 喷墨打印 溶剂 机器学习 

分 类 号：O482.31[理学—固体物理]