[论文解读] Removing Leakage and Surface Recombination in Planar Perovskite Solar Cells

Kristofer Tvingstedt, Lidón Gil‐Escrig+7 more|arXiv (Cornell University)|Feb 18, 2019

Perovskite Materials and Applications参考文献 62被引用 145

一句话总结

论文通过用 polyarylamine 替代 PEDOT:PSS，在平面钙钛矿铅碘太阳能电池中实现漏电（分流）损耗三阶降低，改善低光照工作并减少表面复合。

ABSTRACT

Thin-film solar cells suffer from various types of recombination, of which leakage current usually dominates at lower voltages. Herein, we demonstrate first a three-order reduction of the shunt loss mechanism in planar methylammonium lead iodide perovskite solar cells by replacing the commonly used hole transport layer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with a better hole-selective polyarylamine. As a result, these cells exhibit superior operation under reduced light conditions, which we demonstrate for the extreme case of moonlight irradiance, at which open-circuit voltages of 530 mV can still be obtained. By the shunt removal we also observe the VOC to drop to zero after as long as 2 h after the light has been switched off. Second, at higher illumination intensities the dominant losses in the PEDOT:PSS-based cell are ascribed to surface recombination and are also proven to be substantially minimized by instead employing the polyarylamine. We attribute the reduced shunt and surface recombination to the far better suited semiconductor character of the polyarylamine, compared to that of PEDOT:PSS, efficiently blocking electrons from recombining at this electrode.

研究动机与目标

• Motivate and quantify leakage/shunt losses in planar perovskite solar cells.
• Investigate the impact of hole transport layer choice on recombination and device performance.
• Show improvements in low-light operation and surface recombination with an alternative hole-selective layer.

提出的方法

• 在平面 MAPbI3 太阳能电池中用空穴选择性 polyarylamine 替代 PEDOT:PSS。
• 在降低照明强度下表征器件性能，包括月光级辐照度。
• 分析空穴传输层对漏电流和表面复合的影响。
• 将性能提升归因于 polyarylamine 的半导体特性，该特性更有效地阻止电子在电极处复合。

实验结果

研究问题

• RQ1 空穴传输层的选择如何影响平面钙钛矿太阳能电池的漏电/分流损耗？
• RQ2 在不同照明水平下，用 polyarylamine 替代 PEDOT:PSS 在多大程度上降低了表面复合和漏电？
• RQ3 在低光照和切断光源后，改进的空穴选择性对开路电压有何影响？

主要发现

• 用 polyarylamine 代替 PEDOT:PSS 可实现分流损耗的三阶降低。
• 在月光照度下，可实现高达 530 mV 的开路电压。
• 分流被移除后，关灯约2小时内 VOC 降至零（显示漏电减少）。
• 在较高照明下，作为空穴传输/选择层的 polyarylamine 能显著降低表面复合损失。
• polyarylamine 的改进半导体特性更有效地阻止电子在电极处复合。