School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
ACS Appl Mater Interfaces. 2017 Apr 12;9(14):12629-12636. doi: 10.1021/acsami.6b15762. Epub 2017 Apr 3.
Tungsten oxide as an alternative to conventional acidic PEDOT:PSS has attracted much attention in organic solar cells (OSCs). However, the vacuum-processed WO layer and high-temperature sol-gel hydrolyzed WO are incompatible with large-scale manufacturing of OSCs. Here, we report for the first time that a specific tungsten oxide WO (WO) nanowire can function well as the anode buffer layer. The nw-WO film exhibits a high optical transparency. The power conversion efficiency (PCE) of OSCs based on three typical polymer active layers PTB7:PCBM, PTB7-Th:PCBM, and PDBT-T1:PCBM with nw-WO layer were improved significantly from 7.27 to 8.23%, from 8.44 to 9.30%, and from 8.45 to 9.09%, respectively compared to devices with PEDOT:PSS. Moreover, the photovoltaic performance of OSCs based on small molecule p-DTS(FBTTh):PCBM active layer was also enhanced with the incorporation of nw-WO. The enhanced performance is mainly attributed to the improved short-circuit current density (J), which benefits from the oxygen vacancies and the surface apophyses for better charge extraction. Furthermore, OSCs based on nw-WO show obviously improved ambient stability compared to devices with PEDOT:PSS layer. The results suggest that nw-WO is a promising candidate for the anode buffer layer materials in organic solar cells.
氧化钨作为传统酸性PEDOT：PSS 的替代品，在有机太阳能电池（OSC）中引起了广泛关注。然而，真空处理的 WO 层和高温溶胶-凝胶水解 WO 与 OSC 的大规模制造不兼容。在这里，我们首次报道，特定的氧化钨 WO（WO）纳米线可以很好地用作阳极缓冲层。nw-WO 薄膜表现出高光学透明度。基于三种典型聚合物活性层 PTB7：PCBM、PTB7-Th：PCBM 和 PDBT-T1：PCBM 的 OSCs 的功率转换效率（PCE）分别从具有 PEDOT：PSS 的器件的 7.27%提高到 8.23%、从 8.44%提高到 9.30%、从 8.45%提高到 9.09%。此外，在小分子 p-DTS（FBTTh）：PCBM 活性层的 OSCs 中，掺入 nw-WO 也提高了光伏性能。性能的提高主要归因于短路电流密度（J）的提高，这得益于氧空位和表面突起，有利于更好的电荷提取。此外，与具有 PEDOT：PSS 层的器件相比，基于 nw-WO 的 OSCs 表现出明显改善的环境稳定性。结果表明，nw-WO 是有机太阳能电池中阳极缓冲层材料的有前途的候选材料。
