利用多氟丙烯酸酯添加剂提升准二维钙钛矿发光二极管性能  

Incorporation of a Polyfluorinated Acrylate Additive for High-Performance Quasi-2D Perovskite Light-Emitting Diodes

作　　者：张涛[1,2] 龚思敏[3] 陈平 陈琪 陈立桅[2,4] Tao Zhang;Simin Gong;Ping Chen;Qi Chen;Liwei Chen(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China.;i-Lab,CAS Key Laboratory of Nanophotonic Materials and Devices,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,Jiangsu Province,China;Chongqing Key Laboratory of Micro&Nano Structure Optoelectronics,School of Physical Science and Technology,Southwest University,Chongqing 400715,China;In-situ Center for Physical Sciences,School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China.)

机构地区：[1]中国科学技术大学纳米技术与纳米仿生学院,合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所创新实验室,中科院纳米光子材料与器件重点实验室,江苏苏州215123 [3]西南大学物理科学与技术学院,微纳结构光电子学重庆市重点实验室,重庆400715 [4]上海交通大学化学与化工学院物质科学原位中心,上海200240

出　　处：《物理化学学报》2023年第12期87-94,共8页Acta Physico-Chimica Sinica

基　　金：科技部国家重点研发计划(2021YFA1202802);国家自然科学基金(21875280,21991150,21991153,22022205);中国科学院稳定支持基础研究领域青年团队计划(YSBR-054);江苏省碳达峰碳中和科技创新专项资金(BE2022026);重庆市自然科学基金(CSTB2022NSCQ-MSX0438)资助项目。

摘　　要：准二维钙钛矿由于具有较大的激子结合能和高效的能量转移等优势,在发光二极管(light-emitting diodes,LED)中的应用前景被广泛看好。然而,准二维钙钛矿溶液加工成膜过程中易形成大量的低维相和表界面缺陷,引起严重的非辐射复合,成为限制发光二极管器件性能的瓶颈。在本工作中,通过在PEA2Cs2Pb3Br10钙钛矿前驱体中加入1,6-二(丙烯酰氧基)-2,2,3,3,4,4,5,5-八氟己烷(OFHDODA)小分子添加剂,将钙钛矿薄膜的荧光量子效率(Photoluminescence Quantum Yield,PLQY)从19.7%提升到了49.0%,发射波长从508 nm红移到511 nm。这主要归因于OFHDODA与钙钛矿之间的物理化学相互作用有效抑制了非辐射复合,一方面多氟结构与PEA+之间的氢键相互作用调控了结晶动力学,抑制了低维相的产生;另一方面酯基具有较强的路易斯碱性,钝化了表界面未饱和Pb2+缺陷。相应地,准二维钙钛矿LED的外量子效率(External Quantum Efficiency,EQE)从8.55%提高到了13.76%。这项工作为设计新型多功能小分子添加剂,抑制准二维钙钛矿中的非辐射复合损失提供了思路。Quasi-two-dimensional(quasi-2D)perovskites are one of the most promising luminescent layer candidates for light-emitting diodes(LEDs)because of their excellent optoelectronic properties such as large exciton binding energy,efficient energy transfer,high photoluminescence quantum yield,and adjustable band gap.However,the formation of a large number of low-dimensional phases and surface/interface defects during solution processing of quasi-two-dimensional perovskite films gives rise to an increase in non-radiative recombination,resulting in deteriorated light-emitting diode performance.It is highly desirable to simultaneously realize low-dimensional phase formation inhibition and surface/interface defect passivation during quasi-two-dimensional perovskite film formation.Herein,we report a multifunctional additive,1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane(OFHDODA),which has strong physical and chemical interactions with the PEA2Cs2Pb3Br10 precursor that can effectively suppress non-radiative recombination in the perovskite films.The distinct C=C peak in the Fourier transform infrared spectroscopy(FTIR)spectra and the F 1s peak in the X-ray photoelectron spectroscopy(XPS)spectra showed that OFHDODA molecules were successfully incorporated into the perovskite films,and most OFHDODA molecules existed as monomers.With the addition of OFHDODA,the photoluminescence quantum yield(PLQY)of the perovskite film increased from 19.7%to 49.0%,and the PL emission wavelength red-shifted from 508 to 511 nm.It was demonstrated that hydrogen bond interactions between the polyfluorine structure and PEA+can tune perovskite crystallization dynamics,which inhibit the formation of low-dimensional phases,as shown by the reduced peak intensities at 403 nm(n=1),434 nm(n=2),and 465 nm(n=3)in the absorption spectra.The strong Lewis base moiety of the ester groups passivates the unsaturated Pb2+defects at the surface and grain boundaries of the perovskite films,as evidenced by the Pb 4f peak shift in the XPS spectra and the C=O shift

关 键 词：准二维钙钛矿 非辐射复合 低维相抑制 缺陷钝化 多氟丙烯酸酯添加剂 

分 类 号：O649[理学—物理化学]