Institute of Microstructure Technology , Karlsruhe Institute of Technology , Hermann-von-Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany.
Light Technology Institute , Karlsruhe Institute of Technology , Engesserstrasse 13 , 76131 Karlsruhe , Germany.
ACS Appl Mater Interfaces. 2018 Jul 5;10(26):21985-21990. doi: 10.1021/acsami.8b03024. Epub 2018 Jun 25.
Perovskite solar cells (PSCs) demonstrate excellent power conversion efficiencies (PCEs) but face severe stability challenges. One key degradation mechanism is exposure to ultraviolet (UV) light. However, the impact of different UV bands is not yet well established. Here, we systematically study the stability of PSCs on the basis of a methylammonium lead iodide (CHNHPbI) absorber exposed to (i) 310-317 (UV-B range) and (ii) 360-380 nm (UV-A range), under accelerated conditions. We demonstrate that the investigated UV-B band is detrimental to the stability of PSCs, resulting in PCE degradation by more than 50% after an exposure period >1700 sun-hours. This finding is valid for architectures with a range of electron transport layers, including SnO, compact-TiO, electron-beam TiO, and nanoparticle-TiO. We also show that photodegradation is apparent for high, as well as for low illumination intensities of UV-B light, but not for illumination with UV-A wavelengths. Finally, we show that degradation of PSCs is preventable at the cost of a small fraction of photocurrent by using UV-filtering or luminescent downshifting layers.
钙钛矿太阳能电池 (PSCs) 展现出优异的功率转换效率 (PCE)，但面临严重的稳定性挑战。一个关键的降解机制是暴露在紫外 (UV) 光下。然而，不同 UV 波段的影响尚未得到很好的确立。在这里，我们基于暴露于 (i) 310-317nm（UV-B 范围）和 (ii) 360-380nm（UV-A 范围）的碘化甲基铵铅 (CHNHPbI) 吸收体的 PSCs，在加速条件下系统地研究了其稳定性。我们证明，所研究的 UV-B 波段对 PSCs 的稳定性有害，导致在 >1700 个太阳光小时的暴露后，PCE 下降超过 50%。这一发现适用于具有一系列电子传输层的架构，包括 SnO、致密-TiO、电子束 TiO 和纳米颗粒-TiO。我们还表明，对于高和低强度的 UV-B 光的光降解是明显的，但对于 UV-A 波长的光的光降解不明显。最后，我们表明通过使用 UV 过滤或发光下转换层，可以以牺牲一小部分光电流为代价来防止 PSCs 的降解。
