Lian Xiaomei, Chen Jiehuan, Shan Shiqi, Wu Gang, Chen Hongzheng
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, State Key Laboratory of Silicon Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
ACS Appl Mater Interfaces. 2020 Oct 14;12(41):46340-46347. doi: 10.1021/acsami.0c11731. Epub 2020 Oct 2.
Inverted-structure perovskite solar cells (PVSCs) applying NiO as the hole transport layer (HTL) have attracted increasing attention. It is still a challenge to optimize the contact between NiO and the perovskite layer and to suppress energy loss at the interface. In this study, interface engineering was carried out by modifying the NiO layer with different polymers such as polystyrene, poly(methyl methacrylate) (PMMA), or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) to improve the surface contact between NiO and the perovskite, to decrease the defect states, and to make the energy level alignment better. The NiO/PMMA-based device presents a as high as 1.19 V because of the improved interfacial contact and the interaction of the carbonyl and methoxy group with Pb. The NiO/PTAA-based device with the structure ITO/NiO/PTAA/(MAPbI)(MAPbBrCl)/PCBM/BCP/Ag exhibits the highest power conversion efficiency of 21.56% with a high of 1.19 V. The enhanced performance can be attributed to the deepened highest occupied molecular orbital level of NiO/PTAA, which matched well with that of the perovskite and suppressed interface energy loss as well. This work provides a facile approach for efficiently improving the of NiO-based PVSCs.
采用氧化镍（NiO）作为空穴传输层（HTL）的倒置结构钙钛矿太阳能电池（PVSCs）已引起越来越多的关注。优化NiO与钙钛矿层之间的接触并抑制界面处的能量损失仍然是一个挑战。在本研究中，通过用不同的聚合物（如聚苯乙烯、聚甲基丙烯酸甲酯（PMMA）或聚[双（4-苯基）（2,4,6-三甲基苯基）胺]（PTAA））对NiO层进行改性来进行界面工程，以改善NiO与钙钛矿之间的表面接触，减少缺陷态，并使能级匹配更好。基于NiO/PMMA的器件由于界面接触的改善以及羰基和甲氧基与铅的相互作用，呈现出高达1.19 V的开路电压。具有ITO/NiO/PTAA/（MAPbI）（MAPbBrCl）/PCBM/BCP/Ag结构的基于NiO/PTAA的器件表现出最高的功率转换效率为21.56%，开路电压高达1.19 V。性能的提高可归因于NiO/PTAA的最高占据分子轨道能级的加深，它与钙钛矿的能级很好地匹配，也抑制了界面能量损失。这项工作为有效提高基于NiO的PVSCs的性能提供了一种简便的方法。
