Low-Temperature In Situ Amino Functionalization of TiO2 Nanoparticles Sharpens Electron Management Achieving over 21% Efficient Planar Perovskite Solar Cells
Low-Temperature In Situ Amino Functionalization of TiO2 Nanoparticles Sharpens Electron Management Achieving over 21% Efficient Planar Perovskite Solar Cells
复制标题
低温%20In%20原位%20氨基%20功能化%20of%20TiO2%20纳米颗粒%20锐化%20电子%20管理%20实现%20over%2021%%20高效%20平面%20钙钛矿%20太阳能%20电池
DOI：
10.1002/adma.201806095
复制
发表时间：
2019-02-22
影响因子：
29.4
通讯作者：
Yang, Shangfeng
中科院分区：
文献类型：
--
作者：
Hu, Wanpei;Zhou, Weiran;Yang, Shangfeng
二氧化钛(TiO2)被广泛用作规则结构钙钛矿太阳能电池(PSCs)的电子传输层(ETL)，目前报道的功率转换效率(PCE)在21%以上的PSC大多是基于含有不可或缺的介孔TiO2层的介孔结构。然而，高温(450摄氏度以上)处理是强制性的，这与低成本制造和柔性器件不兼容。本文发展了一种简便的一步、低温、非水解法原位合成氨基功能化的二氧化钛纳米颗粒(简称NH2-TiO2NPs)的方法，即氨基(-NH2)通过Ti-N键化学键连接到纳米颗粒表面。然后将NH2-TiO2NPs作为有效的ETL引入n-i-p平面异质结(PHJ)PSCs中，提供了超过21%的PCE。基于NH2-TiO2ETL的CS(0.05)FA(0.83)MA(0.12)PbI(2.55)Br0.45(简称CsFAMA)PHJ PSC器件表现出最好的PCE为21.33%，明显高于基于原始的TiO2ETL的器件(19.82%)，接近类似结构和制造工艺的器件的PCE纪录。此外，由于钙钛矿薄膜表面陷阱态的钝化，显著抑制了电流-电压响应的滞后，氨基功能化提高了器件的环境稳定性。
Titanium oxide (TiO2) has been commonly used as an electron transport layer (ETL) of regular-structure perovskite solar cells (PSCs), and so far the reported PSC devices with power conversion efficiencies (PCEs) over 21% are mostly based on mesoporous structures containing an indispensable mesoporous TiO2 layer. However, a high temperature annealing (over 450 degrees C) treatment is mandatory, which is incompatible with low-cost fabrication and flexible devices. Herein, a facile one-step, low-temperature, nonhydrolytic approach to in situ synthesizing amino-functionalized TiO2 nanoparticles (abbreviated as NH2-TiO2 NPs) is developed by chemical bonding of amino (-NH2) groups, via Ti-N bonds, onto the surface of TiO2 NPs. NH2-TiO2 NPs are then incorporated as an efficient ETL in n-i-p planar heterojunction (PHJ) PSCs, affording PCE over 21%. Cs(0.05)FA(0.83)MA(0.12)PbI(2.55)Br(0.45) (abbreviated as CsFAMA) PHJ PSC devices based on NH2-TiO2 ETL exhibit the best PCE of 21.33%, which is significantly higher than that of the devices based on the pristine TiO2 ETL (19.82%) and is close to the record PCE for devices with similar structures and fabrication procedures. Besides, due to the passivation of the surface trap states of perovskite film, the hysteresis of current-voltage response is significantly suppressed, and the ambient stability of devices is improved upon amino functionalization.