钙钛矿太阳能电池纳米纤维改性电子传输层研究

Nanofiber-modified Electron Transport Layer for Perovskite Solar Cells

二氧化锡(SnO_(2))由于具有高透光率、高电子迁移率、良好的紫外稳定性以及可低温加工等优势,作为电子传输材料在钙钛矿太阳能电池(PSC)中得到广泛应用。然而,用商业胶体溶液制备的SnO_(2)电子传输层仍然存在易团聚、缺陷多、能级不匹配等问题,限制了器件性能和稳定性。本研究将一种高分子甲壳素纳米纤维(1,2-二苯甲酰氧基苯基甲壳素,DC)引入到SnO_(2)前驱液中来改善SnO_(2)薄膜质量,系统研究了DC对前驱液、薄膜和器件性能的影响。实验结果表明,DC添加剂能够有效抑制纳米颗粒团聚,使前驱液分散得更均匀。改善后的SnO_(2)薄膜的粗糙度更小,能更好地被钙钛矿溶液浸润,有利于SnO_(2)与钙钛矿层形成更紧密的接触。同时,SnO_(2)薄膜中的氧空位缺陷被有效钝化,缺陷占比降低至30%,进一步提升了薄膜质量。改进后SnO_(2)电子传输层与钙钛矿层的能级匹配性更好,载流子提取和传输性能得到优化。DC改性后的PSC性能得到显著提升,最优器件的光电转换效率达到19.11%。本工作不仅解决了SnO_(2)电子传输层在制备过程中的团聚问题,而且为提高PSC能提供了理论指导与方法。

Tin dioxide(SnO_(2))is widely used in perovskite solar cell(PSC)as an electron transport material due to its high transmittance,high electron mobility,good UV stability,and low-temperature processing.However,SnO_(2)electron transport layer prepared from commercial colloidal solution still faces some challenges such as easy agglomeration,defects,and energy level mismatch,limiting its performance and stability.This study improved the quality of SnO_(2)films by introducing a polymer chitin nanofiber(1,2-dibenzoyloxyphenylchitin,DC)into the SnO_(2)precursor solution,and systematically studied the effect of DC on the precursor solution,film and device performance.Experimental results showed that DC additive could effectively inhibit the agglomeration of SnO_(2)nanoparticles,ensuring a more homogeneous dispersion in the precursor solution.The improved SnO_(2)films had smaller roughness and could be better wetted by perovskite solution,which is beneficial to closer contact with the perovskite layer.Simultaneously,the oxygen vacancy defects in the SnO_(2)films were effectively passivated,and the proportion of defects was reduced to 30%,further improving the quality of the films.Based on the improved energy level matching between the SnO_(2)electron transport layer and the perovskite layer,the carrier extraction and transport performance was optimized.The performance of DC-modified PSC was significantly improved,and the photoelectric conversion efficiency of the optimal device reached 19.11%.This work not only overcomes the agglomeration problem of the SnO_(2)electron transport layer during the preparation process,but also provides theoretical guidance and method for improving the performance of perovskite solar cells.