Zhang Zongbao, Ji Ran, Hofstetter Yvonne J, Deconinck Marielle, Brunner Julius, Li Yanxiu, An Qingzhi, Vaynzof Yana
Chair for Emerging Electronic Technologies, Technische Universität Dresden Nöthnitzer Straße 61 01187 Dresden Germany
Leibniz-Institute for Solid State and Materials Research Dresden Helmholtzstraße 20 01069 Dresden Germany.
J Mater Chem A Mater. 2023 Jul 10;11(30):16115-16126. doi: 10.1039/d3ta03249c. eCollection 2023 Aug 2.
Inorganic cesium lead iodide (CsPbI) perovskite solar cells (PSCs) have attracted enormous attention due to their excellent thermal stability and optical bandgap (∼1.73 eV), well-suited for tandem device applications. However, achieving high-performance photovoltaic devices processed at low temperatures is still challenging. Here we reported a new method for the fabrication of high-efficiency and stable γ-CsPbI PSCs at lower temperatures than was previously possible by introducing the long-chain organic cation salt ethane-1,2-diammonium iodide (EDAI) and regulating the content of lead acetate (Pb(OAc)) in the perovskite precursor solution. We find that EDAI acts as an intermediate that can promote the formation of γ-CsPbI, while excess Pb(OAc) can further stabilize the γ-phase of CsPbI perovskite. Consequently, improved crystallinity and morphology and reduced carrier recombination are observed in the CsPbI films fabricated by the new method. By optimizing the hole transport layer of CsPbI inverted architecture solar cells, we demonstrate efficiencies of up to 16.6%, surpassing previous reports examining γ-CsPbI in inverted PSCs. Notably, the encapsulated solar cells maintain 97% of their initial efficiency at room temperature and under dim light for 25 days, demonstrating the synergistic effect of EDAI and Pb(OAc) in stabilizing γ-CsPbI PSCs.
无机铯铅碘化物（CsPbI）钙钛矿太阳能电池（PSC）因其出色的热稳定性和光学带隙（约1.73 eV）而备受关注，非常适合用于串联器件应用。然而，实现低温处理的高性能光伏器件仍然具有挑战性。在此，我们报告了一种新方法，通过引入长链有机阳离子盐乙烷-1,2-二碘化铵（EDAI）并调节钙钛矿前驱体溶液中醋酸铅（Pb(OAc)）的含量，在比以往更低的温度下制备高效且稳定的γ-CsPbI PSC。我们发现EDAI作为一种中间体，可以促进γ-CsPbI的形成，而过量的Pb(OAc)可以进一步稳定CsPbI钙钛矿的γ相。因此，在通过新方法制备的CsPbI薄膜中观察到结晶度和形貌得到改善，载流子复合减少。通过优化CsPbI倒置结构太阳能电池的空穴传输层，我们展示了高达16.6%的效率，超过了之前关于倒置PSC中γ-CsPbI的报道。值得注意的是，封装后的太阳能电池在室温及暗光条件下25天内保持其初始效率的97%，证明了EDAI和Pb(OAc)在稳定γ-CsPbI PSC方面的协同作用。
