Wang Qingqian, Shao Shuyan, Xu Bowei, Duim Herman, Dong Jingjin, Adjokatse Sampson, Portale Giuseppe, Hou Jianhui, Saba Michele, Loi Maria A
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen 9747 AG, The Netherlands.
Photonics and Optoelectronics Lab, Department of Physics, University of Cagliari, Monserrato I-09042, Italy.
ACS Appl Mater Interfaces. 2020 Jul 1;12(26):29505-29512. doi: 10.1021/acsami.0c05290. Epub 2020 Jun 17.
Recent works demonstrate that polyelectrolytes as a hole transport layer (HTL) offers superior performance in Ruddlesden-Popper perovskite solar cells (RPPSCs) compared to poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The factors contributing to such improvement need to be systematically investigated. To achieve this, we have systematically investigated how the two HTLs affect the morphology, crystallinity, and orientation of the Ruddlesden-Popper perovskite (RPP) films as well as the charge extraction of the RPPSCs. PEDOT:PSS as a HTL leads to RPP films of low crystallinity and with a number of large pinholes. These factors lead to poor charge carrier extraction and significant charge recombination in the RPPSCs. Conversely, a PCP-Na HTL gives rise to highly crystalline and pinhole-free RPPSC films. Moreover, a PCP-Na HTL provides a better energy alignment at the perovskite/HTL interface because of its higher work function compared to PEDOT:PSS. Consequently, devices using PCP-Na as HTLs are more efficient in extracting charge carriers.
近期研究表明，与聚（3,4-乙撑二氧噻吩）聚苯乙烯磺酸盐（PEDOT:PSS）相比，聚电解质作为空穴传输层（HTL）在Ruddlesden-Popper钙钛矿太阳能电池（RPPSCs）中表现出更优异的性能。导致这种性能提升的因素需要进行系统研究。为实现这一目标，我们系统地研究了这两种空穴传输层如何影响Ruddlesden-Popper钙钛矿（RPP）薄膜的形貌、结晶度和取向，以及RPPSCs的电荷提取。PEDOT:PSS作为空穴传输层会导致RPP薄膜结晶度低且有大量大的针孔。这些因素导致RPPSCs中电荷载流子提取不佳和显著的电荷复合。相反，PCP-Na空穴传输层会产生高度结晶且无针孔的RPPSC薄膜。此外，由于PCP-Na空穴传输层与PEDOT:PSS相比具有更高的功函数，它在钙钛矿/空穴传输层界面提供了更好的能量对准。因此，使用PCP-Na作为空穴传输层的器件在提取电荷载流子方面更高效。
