Amelot Dylan, Ahmadpour Mehrad, Ros Quim, Cruguel Hervé, Casaretto Nicolas, Cossaro Albano, Floreano Luca, Madsen Morten, Witkowski Nadine
Sorbonne Université, UMR CNRS 7588, Institut des Nanosciences de Paris, 4 Pl. Jussieu, F-75005 Paris, France.
SDU NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, Sønderborg DK-6400, Denmark.
ACS Appl Mater Interfaces. 2021 Apr 28;13(16):19460-19466. doi: 10.1021/acsami.1c01966. Epub 2021 Apr 19.
Organic photovoltaics (OPVs) technology now offers power conversion efficiency (PCE) of over 18% and is one of the main emerging photovoltaic technologies. In such devices, titanium dioxide (TiO) has been vastly used as an electron extraction layer, typically showing unwanted charge-extraction barriers and the need for light-soaking. In the present work, using advanced photoemission spectroscopies, we investigate the electronic interplay at the interface between low-temperature-sputtered TiO and C acceptor fullerene molecules. We show that defect states in the band gap of TiO are quenched by C while an interfacial state appears. This new interfacial state is expected to support the favorable energy band alignment observed, showing a perfect match of transport levels, and thus barrier-free extraction of charges, making low-temperature-sputtered TiO a good candidate for the next generation of organic solar cells.
有机光伏（OPV）技术目前的功率转换效率（PCE）超过18%，是主要的新兴光伏技术之一。在这类器件中，二氧化钛（TiO）被广泛用作电子提取层，但通常存在不必要的电荷提取势垒以及需要进行光浸泡处理的问题。在本工作中，我们使用先进的光发射光谱技术，研究了低温溅射的TiO与C受体富勒烯分子之间界面处的电子相互作用。我们发现TiO带隙中的缺陷态被C淬灭，同时出现了一个界面态。这个新的界面态有望支持所观察到的有利能带排列，显示出传输能级的完美匹配，从而实现无势垒电荷提取，使低温溅射的TiO成为下一代有机太阳能电池的良好候选材料。
