物理化学学报 >> 2021, Vol. 37 >> Issue (4): 2008050.doi: 10.3866/PKU.WHXB202008050

所属专题: 金属卤化物钙钛矿光电材料和器件

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基于吡嗪空穴传输层的合成及在p -i-n型钙钛矿太阳能电池中的应用

许桂英1, 薛荣明1, 张默瑶1, 李耀文1,*(), 李永舫1,2   

  1. 1 先进光电材料重点实验室,苏州大学材料与化学化工学部,江苏 苏州 215123
    2 中国科学院化学研究所,北京分子科学国家研究中心,北京 100190
  • 收稿日期:2020-08-19 录用日期:2020-09-23 发布日期:2020-10-09
  • 通讯作者: 李耀文 E-mail:ywli@suda.edu.cn
  • 基金资助:
    国家自然科学基金(51922074);国家自然科学基金(51673138);国家自然科学基金(51820105003);江苏高校优势学科建设工程项目和江苏省研究生科研与实践创新计划项目(KYCPTTPA8_2496)

Synthesis of Pyrazine-based Hole Transport Layer and Its Application in p-i-n Planar Perovskite Solar Cells

Guiying Xu1, Rongming Xue1, Moyao Zhang1, Yaowen Li1,*(), Yongfang Li1,2   

  1. 1 Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, Jiangsu Province, China
    2 Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2020-08-19 Accepted:2020-09-23 Published:2020-10-09
  • Contact: Yaowen Li E-mail:ywli@suda.edu.cn
  • About author:Yaowen Li, Email: ywli@suda.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(51922074);the National Natural Science Foundation of China(51673138);the National Natural Science Foundation of China(51820105003);the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and Postgraduate Research & Practice Innovation Program of Jiangsu Province(KYCPTTPA8_2496)

摘要:

钙钛矿太阳能电池由于具有高的光电转换效率,简单的溶液加工工艺,较低的成本等优势因而拥有广阔的应用前景。有机小分子空穴传输层材料在钙钛矿太阳能电池中扮演着极其重要的角色。在本工作中,我们设计和合成了基于吡嗪为分子中心核,三苯胺为分枝的X型空穴传输层材料PT-TPA。与Si-OMeTPA对比,吡嗪的引入不仅不会影响其结晶性,并且能够改善其电荷转移特性和分子中心共平面性,从而显著提升了PT-TPA的空穴迁移率。在非掺杂的情况之下,基于PT-TPA空穴传输层的p-i-n型钙钛矿太阳能电池展现出17.52%的光电转换效率,与相同条件下基于Si-OMeTPA空穴传输层的器件相比,效率提高了近15%。

关键词: 吡嗪, 空穴传输层, 有机小分子, p-i-n型钙钛矿太阳能电池, 结构与性能关系

Abstract:

Planar p-i-n perovskite solar cells (pero-SCs) with solution-processed fabrication, low cost, flexible device fabrication, and negligible hysteresis have attracted significant interest. Hole transport material (HTM) plays a crucial role in improving the performance of p-i-n planar pero-SCs by facilitating hole extraction and then reducing surface recombination. Two types of HTMs have been used in p-i-n pero-SCs. p-Type inorganic semiconductors, such as NiO, CuI, Cu2O, CuSCN, and graphene oxide, have shown good efficiency and stability; however, organic semiconductor-based HTMs (e.g., poly[bis(4-phenyl) (2, 4, 6-trimethylphenyl)amine] (PTAA), polyarylamine (poly-TPD), poly(N-9-heptadecanyl-2, 7-carbazole-alt-5, 5-(4, 7-di(thien-2-yl)-2, 1, 3-benzothiadiazole)) (PCDTBT), and triphenylamine or thiophene derivative) have outstanding processability for simple one-step solution process at low temperatures; therefore, they should be investigated further. However, their electrical properties are usually inferior than those of inorganic semiconductors, and additives are required to improve their mobility and conductivity, which complicates device processing and results in hysteresis and poor device stability. Therefore, for the organic semiconductor-based HTMs, new hole transport layer (HTL) materials should be developed with easy synthesis process, highly reproducible photovoltaic performance, and better understanding of the structure–property relationship between the HTL materials and the device performance. Herein, an X-type HTM 4, 4, 4'', 4'''-(pyrazine-2, 3, 5, 6-tetrayl)tetrakis(N, N-bis(4-methoxyphenyl)aniline) (PT-TPA) containing pyrazine as the molecular core and triphenylamine (TPA) derivative as branches was designed and synthesized. We introduce an electron-deficient para-diazine as the core and electron-donating methoxytriphenylamine as the peripheral unit to enhance the dipole moment of PT-TPA, which could induce an intermolecular charge transfer. Compared with 4, 4'', 4'', 4'''-silanetetrayltetrakis(N, N-bis(4-methoxyphenyl)aniline) (Si-OMeTPA), the pyrazine core not only endows PT-TPA with good crystallinity but also improves the charge transfer property and plane conjugation of the molecular center, which significantly enhances the hole mobility of PT-TPA. The p-i-n planar pero-SCs based on dopant-free PT-TPA HTL showed a power conversion efficiency of 17.52%, which is approximately 15% higher than that of the device with a Si-OMeTPA HTL.

Key words: Pyrazine, Hole-transporting layer, Organic small molecule, p-i-n planar perovskite solar cell, Structure and property relationship

MSC2000: 

  • O646