物理化学学报 >> 2021, Vol. 37 >> Issue (4): 2007021.doi: 10.3866/PKU.WHXB202007021

所属专题: 金属卤化物钙钛矿光电材料和器件

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ALD-Al2O3涂层保护的高抗湿5-氨基戊酸铰链甲胺铅溴钙钛矿薄膜

王甜, 张太阳, 陈悦天(), 赵一新()   

  • 收稿日期:2020-07-09 录用日期:2020-08-05 发布日期:2020-08-07
  • 通讯作者: 陈悦天,赵一新 E-mail:yuetian.chen@sjtu.edu.cn;yixin.zhao@sjtu.edu.cn
  • 基金资助:
    国家自然科学基金(51861145101);国家自然科学基金(21777096);上海市教委曙光计划(17SG11)

Highly Moisture Resistant 5-Aminovaleric Acid Crosslinked CH3NH3PbBr3 Perovskite Film with ALD-Al2O3 Protection

Tian Wang, Taiyang Zhang, Yuetian Chen(), Yixin Zhao()   

  • Received:2020-07-09 Accepted:2020-08-05 Published:2020-08-07
  • Contact: Yuetian Chen,Yixin Zhao E-mail:yuetian.chen@sjtu.edu.cn;yixin.zhao@sjtu.edu.cn
  • About author:Email:yixin.zhao@sjtu.edu.cn (Y.Z.)
    Email: yuetian.chen@sjtu.edu.cn (Y.C.)
  • Supported by:
    the National Natural Science Foundation of China(51861145101);the National Natural Science Foundation of China(21777096);the Shanghai Shuguang Grant, China(17SG11)

摘要:

近年来,混合铅卤钙钛矿材料在光电领域引发的研究热潮引人注目。然而,钙钛矿材料对水和氧气的敏感性严重的阻碍了其实用化进程。在众多的稳定钙钛矿的方法中,利用简单的原子层沉积方法(Atomic layer deposition,ALD)在钙钛矿表面沉积一层保护层的技术具有极大的潜力。而ALD应用的困难在于,在常规的ALD过程中,做为氧源的H2O和O3对铅卤钙钛矿有着腐蚀作用。在本文,我们提出将双官能团的5-氨基戊酸(5-Aminovaleric acid,AVA)引入到CH3NH2PbBr3 (MAPbBr3)钙钛矿晶格层中,形成稳定的铰链结构的2D/3D钙钛矿AVA(MAPbBr3)2。AVA的引入可以钝化并防止ALD过程中水对钙钛矿的侵蚀,从而成功地直接在钙钛矿表面沉积了Al2O3保护层。覆盖了保护层的AVA(MAPbBr3)2钙钛矿薄膜获得了优异的热稳定性和抗水性。

关键词: 铅卤钙钛矿, 原子层沉积, 铰链2D/3D结构, 热稳定性, 抗水性

Abstract:

In recent years, hybrid lead halide perovskites have attracted significant research interest in the optoelectronic fields owing to their exceptional physical and chemical properties. However, their commercialization process is limited largely because of the sensitive nature of perovskite materials towards external stresses, such as heat, UV irradiance, oxygen, and moisture. Among various perovskite-stabilization methods, deposition of a protective layer over the vulnerable perovskite film via simple atomic layer deposition (ALD) technology is of great potential. However, the corrosive effect of H2O or O3 on perovskites, which is used as the oxygen source during ALD process, is one of the main obstacles in the application of regular ALD technology for coating compact and highly conformal layer directly onto the perovskite film. In this study, by introducing bifunctional 5-aminovaleric acid (AVA) crosslinking into the layers of CH3NH3PbBr3 (MAPbBr3) units, we propose a simple yet effective strategy to prevent the degradation of sensitive perovskite structure during the ALD process when H2O is used as the oxygen source. The formed crosslinked 2D/3D structure of AVA(MAPbBr3)2 perovskite film was extremely dense and ultra-smooth compared to the coarse MAPbBr3 film. With the passivation and protection of AVA, the AVA(MAPbBr3)2 perovskite film exhibited high moisture resistance, thereby leading to the successful deposition of dense and conformal Al2O3 protective layer onto the perovskite surface. The deposition of Al2O3 layer with different thicknesses had a negligible effect on the crystalline phase and morphology of AVA(MAPbBr3)2 film, as confirmed by X-ray diffraction, UV-Vis absorption spectroscopy, and scanning electron microscopy characterizations. The steady-state photoluminescence (PL) intensity and time-resolved PL lifetime of AVA(MAPbBr3)2 film was kept almost unchanged before and after the coating of Al2O3 layer, suggesting that the thin Al2O3 layer did not significantly alter the optical properties of the perovskite material, thereby enabling the potential usages in optical and optoelectronic devices. The thermal stability and water resistance ability of Al2O3-coated AVA(MAPbBr3)2 film was proven to have greatly improved in accelerated circumstances. No impurities or decomposition were detected for Al2O3-coated AVA(MAPbBr3)2 film after the long-time annealing at high temperature (150 ℃ for 2 h), whereas the crosslinked 2D/3D structure of bare MAPbBr3 film quickly broke down at the elevated temperature. Intriguingly, the AVA(MAPbBr3)2 film with 15-nm-thick Al2O3 coating layer could endure strong water corrosion for at least 10 min when immersed in water. Overall, the proposed strategy could not only give a good reference for successfully depositing metal oxides onto the perovskite films with preservation of the materials' intrinsic properties, but also provide a method of introducing amino acid to passivate and protect the perovskite materials from H2O corrosion during the ALD process. Therefore, the proposed work has practical potential in improving the device stability against various external stresses under different operating conditions, thereby paving way for various applicational advances.

Key words: Lead halide perovskite, Atomic layer deposition, Crosslinked 2D/3D structure, Thermal stability, Water resistance

MSC2000: 

  • O649