Zhang Zhewei, Sheri Madhu, Page Zachariah A, Emrick Todd, Saeki Akinori, Liu Yao, Russell Thomas P
Beijing Advanced Innovation Center for Soft Matter, Science and Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States.
ACS Appl Mater Interfaces. 2020 Dec 16;12(50):56068-56075. doi: 10.1021/acsami.0c18108. Epub 2020 Dec 7.
This paper describes a correlation between charge extraction and energy-level alignment at the interface of polymeric hole transport layers and perovskite active layers. By tailoring the composition of the conjugated backbone of the hole transport material, energy levels between perovskites and hole transport layers are varied. Matching the band alignment at perovskite/hole transport interfaces dramatically improved charge extraction and thus device performance. Time-resolved microwave conductivity measurements, performed to elucidate hole transfer kinetics, suggest that hole transport layer energy levels greatly influence hole extraction efficiency at this interface, a finding that agrees well with device performance metrics. Furthermore, photoluminescence, Mott-Schottky, and space charge limited current measurements support that energy-level alignment between the hole transport layer and perovskite active layer enables more efficient hole extraction and transport at the device interface. The insight surrounding hole extraction in inverted perovskite devices will help design effective hole transport materials, which, in turn, facilitates the production of more efficient solar cells.
本文描述了聚合物空穴传输层与钙钛矿活性层界面处的电荷提取与能级排列之间的相关性。通过调整空穴传输材料共轭主链的组成，钙钛矿与空穴传输层之间的能级会发生变化。匹配钙钛矿/空穴传输界面处的能带排列可显著改善电荷提取，从而提高器件性能。为阐明空穴转移动力学而进行的时间分辨微波电导率测量表明，空穴传输层能级对该界面处的空穴提取效率有很大影响，这一发现与器件性能指标高度吻合。此外，光致发光、莫特-肖特基和空间电荷限制电流测量结果均支持，空穴传输层与钙钛矿活性层之间的能级排列能够在器件界面实现更高效的空穴提取和传输。对倒置钙钛矿器件中空穴提取的深入了解将有助于设计有效的空穴传输材料，进而推动更高效率太阳能电池的生产。
