Boldyreva Aleksandra G, Zhidkov Ivan S, Tsarev Sergey, Akbulatov Azat F, Tepliakova Marina M, Fedotov Yury S, Bredikhin Sergey I, Postnova Evgeniya Yu, Luchkin Sergey Yu, Kurmaev Ernst Z, Stevenson Keith J, Troshin Pavel A
Skolkovo Institute of Science and Technology, Nobel Street 3, 143026 Moscow, Russia.
Russia Institute of Physics and Technology, Ural Federal University, Mira 9 str., 620002 Yekaterinburg, Russia.
ACS Appl Mater Interfaces. 2020 Apr 22;12(16):19161-19173. doi: 10.1021/acsami.0c01027. Epub 2020 Apr 13.
We investigated the impact of a series of hole transport layer (HTL) materials such as Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), NiO, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA), and polytriarylamine (PTA) on photostability of thin films and solar cells based on MAPbI, CsFAPbI, CsMAFAPbI, CsMAFAPb(BrI), and CsFAPb(BrI) complex lead halides. Mixed halide perovskites showed reduced photostability in comparison with similar iodide-only compositions. In particular, we observed light-induced recrystallization of all perovskite films except MAPbI with the strongest effects revealed for Br-containing systems. Moreover, halide and β FAPbI phase segregations were also observed mostly in mixed-halide systems. Interestingly, coating perovskite films with the PCBM layer spectacularly suppressed light-induced growth of crystalline domains as well as segregation of Br-rich and I-rich phases or β FAPbI. We strongly believe that all three effects are promoted by the light-induced formation of surface defects, which are healed by adjacent PCBM coating. While comparing different hole-transport materials, we found that NiO and PEDOT:PSS are the least suitable HTLs because of their interfacial (photo)chemical interactions with perovskite absorbers. On the contrary, polyarylamine-type HTLs PTA and PTAA form rather stable interfaces, which makes them the best candidates for durable p-i-n perovskite solar cells. Indeed, multilayered ITO/PTA(A)/MAPbI/PCBM stacks revealed no aging effects within 1000 h of continuous light soaking and delivered stable and high power conversion efficiencies in solar cells. The obtained results suggest that using polyarylamine-type HTLs and simple single-phase perovskite compositions pave a way for designing stable and efficient perovskite solar cells.
我们研究了一系列空穴传输层（HTL）材料，如聚（3,4-乙撑二氧噻吩）聚苯乙烯磺酸盐（PEDOT:PSS）、NiO、聚[双（4-苯基）（2,4,6-三甲基苯基）胺]（PTAA）和聚三芳基胺（PTA）对基于MAPbI、CsFAPbI、CsMAFAPbI、CsMAFAPb(BrI)和CsFAPb(BrI)复合铅卤化物的薄膜和太阳能电池光稳定性的影响。与类似的仅含碘化物的组合物相比，混合卤化物钙钛矿的光稳定性降低。特别是，我们观察到除MAPbI外的所有钙钛矿薄膜的光致重结晶，含溴体系的效果最为明显。此外，卤化物和β-FAPbI相分离也主要在混合卤化物体系中观察到。有趣的是，用PCBM层涂覆钙钛矿薄膜显著抑制了晶畴的光致生长以及富溴和富碘相或β-FAPbI的分离。我们坚信，所有这三种效应都是由光致表面缺陷的形成所促进的，这些缺陷通过相邻的PCBM涂层得以修复。在比较不同的空穴传输材料时，我们发现NiO和PEDOT:PSS是最不合适的HTL，因为它们与钙钛矿吸收剂存在界面（光）化学相互作用。相反，聚芳基胺型HTL PTA和PTAA形成相当稳定的界面，这使它们成为耐用的p-i-n钙钛矿太阳能电池的最佳候选材料。事实上，多层ITO/PTA(A)/MAPbI/PCBM堆叠在连续光照浸泡1000小时内未显示出老化效应，并且在太阳能电池中提供了稳定且高的功率转换效率。所得结果表明，使用聚芳基胺型HTL和简单的单相钙钛矿组合物为设计稳定高效的钙钛矿太阳能电池铺平了道路。
