Device structure and perovskite composition are two of the most important factors for maximizing the efficiency of light emitting diodes with perovskite as the light emitting layer. However, combining the best structures reported does not necessarily lead to better device performance. In the present study, the authors examine the device performance affected by the interplay between polyvinylpyrrolidone (PVP) as the interlayer and cesium (Cs)- or formamidinium (FA)-based perovskite composition (PEA₂(Cs_0.87MA_0.13)₄Pb₅Br₁₆ (PEA: phenyl ethyl ammonium cation, MA: methyl ammonium cation) or PEA₂FA₂Pb₃Br₁₀, respectively). In the case of Cs-based perovskite light-emitting diodes (PeLEDs), PVP improves the formation of perovskite by preventing intermixing at the interface, thereby improving the device efficiency. On the other hand, although PVP is thought to behave similarly on FA-based perovskite, it degrades device efficiency by decreasing hole injection and shifting the charge balance due to its insulating property. Based on the analysis, high efficiency Cs- and FA-based PeLEDs of 12.31 and 24.5 cd A^−1, respectively, are obtained.

中文翻译：

---

聚乙烯吡咯烷酮中间层与钙钛矿成分相互作用影响钙钛矿发光二极管性能的研究

器件结构和钙钛矿成分是使以钙钛矿为发光层的发光二极管的效率最大化的两个最重要的因素。然而，结合报告的最佳结构并不一定会导致更好的器件性能。在本研究中，作者检查了作为中间层的聚乙烯吡咯烷酮 (PVP) 与基于铯 (Cs) 或甲脒 (FA) 的钙钛矿组合物 (PEA ₂ (Cs _0.87 MA _0.13 ) ₄ Pb ₅之间的相互作用影响的器件性能。Br ₁₆（PEA：苯乙基铵阳离子，MA：甲基铵阳离子）或 PEA ₂ FA ₂ Pb ₃ Br₁₀，分别）。在 Cs 基钙钛矿发光二极管 (PeLED) 的情况下，PVP 通过防止界面处的混合来改善钙钛矿的形成，从而提高器件效率。另一方面，尽管 PVP 被认为在 FA 基钙钛矿上表现相似，但由于其绝缘特性，它会通过减少空穴注入和改变电荷平衡来降低器件效率。根据分析，获得了分别为 12.31 和 24.5 cd A ^{^1 的}高效 Cs 和 FA 基 PeLED 。