物理化学学报2023，Vol.39Issue(12)：87-94,8.DOI:10.3866/PKU.WHXB202301024
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
摘要
Abstract
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 in the FTIR spectra.The trap-filled limiting voltage(VTFL)decreased in both hole-only and electron-only devices,which also proves the reduction of Pb2+defects.At the optimized OFHDODA concentration,the scanning electron microscopy(SEM)and atomic force microscopy(AFM)results from the perovskite films show lower roughness and smoother surface potential,which promotes superior interfacial contact.As a result,perovskite LEDs with a device structure of indium tin oxide glass/poly(9-vinylcarbazole)/perovskite/1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene/8-hydroxyquinolinolato-lithium/Al exhibited an improved maximum external quantum efficiency(EQE)from 8.55％to 13.76％,improved maximum brightness from 16400 to 17620 cd·m-2,and increased lifetime from 8 min to 12 min.This process provides an effective way to suppress non-radiative recombination in quasi-2D perovskites via additive molecular structure design,leading to superior electroluminescence performance.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Key words
Quasi-two-dimensional perovskite/Non-radiative recombination/Low-dimensional inhibition/Defect passivation/Polyfluorinated acrylate additive分类
化学化工引用本文复制引用
张涛,龚思敏,陈平,陈琪,陈立桅..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[J].物理化学学报,2023,39(12):87-94,8.基金项目
The project was supported by the Ministry of Science and Technology of China(2021YFA1202802),the National Natural Science Foundation of China(21875280,21991150,21991153,22022205),the CAS Project for Young Scientists in Basic Research(YSBR-054),the Special Foundation for Carbon Peak Neutralization Technology Innovation Program of Jiangsu Province(BE2022026)and the Natural Science Foundation Project of Chongqing(CSTB2022NSCQ-MSX0438).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)和重庆市自然科学基金(CSTB2022NSCQ-MSX0438)资助项目 （2021YFA1202802）
