Kim Jung Kyu
School of Chemical Engineering, Sungkyunkwan University (SKKU), Seobu-ro 2066, Jangan-gu, Suwon 16419, Korea.
Polymers (Basel). 2019 Jan 11;11(1):120. doi: 10.3390/polym11010120.
As a -type metal oxide, nickel oxide (NiO) has been extensively utilized for providing a favorable hole transport pathway in organic solar cells (OSCs). To obtain higher crystallinity, a post-annealing process at high temperature is required for the NiO layer. Therefore, fluorine-doped tin oxide (FTO) glass has been widely used for the substrate of NiO. However, the rough surface of the FTO substrate deteriorates the interfacial properties of the NiO layer, which hinders efficient charge extraction in OSCs. In this study, a facile polyethylene glycol (PEG)-assisted sol-gel synthesis of the compact NiO layer as the hole-selective layer is demonstrated. The compact NiO layer has a significantly uniform and smooth surface morphology, facilitating better interfacial properties for favorable charge transport. The modified interfacial properties outstandingly promote the charge migration and recombination blocking in OSCs. In addition, a hybrid structure with compact NiO and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is designed to form a cascade charge extraction and passivate possible pinholes on the NiO layer. Consequently, the compact NiO layer enhances all the parameters determining the power conversion efficiency, including the open-circuit potential (), short-circuit current density (), and fill factor ().
作为一种α型金属氧化物，氧化镍（NiO）已被广泛用于在有机太阳能电池（OSC）中提供良好的空穴传输途径。为了获得更高的结晶度，NiO层需要在高温下进行后退火处理。因此，氟掺杂氧化锡（FTO）玻璃已被广泛用作NiO的基板。然而，FTO基板的粗糙表面会降低NiO层的界面性能，这阻碍了OSC中的有效电荷提取。在本研究中，展示了一种简便的聚乙二醇（PEG）辅助溶胶 - 凝胶法合成致密NiO层作为空穴选择性层。致密NiO层具有显著均匀且光滑的表面形态，有利于实现更好的界面性能以促进电荷传输。改性后的界面性能显著促进了OSC中的电荷迁移和复合阻挡。此外，设计了一种具有致密NiO和聚（3,4 - 亚乙基二氧噻吩）聚苯乙烯磺酸盐（PEDOT:PSS）的混合结构，以形成级联电荷提取并钝化NiO层上可能存在的针孔。因此，致密NiO层提高了所有决定功率转换效率的参数，包括开路电势（）、短路电流密度（）和填充因子（）。
