Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV18)
Publication date: 21st February 2018
Solid-state organic hole transporting materials (HTMs) are one of the important components of the perovskite solar cells (PSCs), ensuring stability of the perovskite absorber layer, good charge separation, and as a consequence high performance of the devices. Currently, Spiro-OMeTAD is the most popular choice for the HTM layer, and is used for the majority of the state-of-the-art PSC devices. However, due to the complicated multi-step synthetic procedure, price of the Spiro-OMeTAD remains at a very high level. To overcome this drawback, novel small-molecule HTMs V1050 and V1061 were designed and synthesized. Synthesis was performed using a facile three-step synthetic route, starting from simple fluorene molecules.Coplanar central core were previously shown to have positive effect on the efficiency of HTM [1]. As a hole transporting fragment, 4,4′-dimethoxydiphenylamine 3,6-disubstituted carbazole was used, due to its good performance in PSCs [2]. PSCs of planar configuration, employing V1050 HTM showed a high power conversion efficiency of 18.3%, which is comparable to the 18.9% efficiency, obtained in the same device configuration, only using Spiro-OMeTAD as a HTM. In addition, devices with V1050 and V1061 showed better stability in comparison to Spiro-OMeTAD based devices. Aging test was performed on a non-encapsulated devices under uncontrolled humidity conditions (relative humidity around 60%) in the dark and under continuous full sun illumination. Overall, we believe that V1050 can became a cheaper alternative to the Spiro-OMeTAD, thus contributing to the faster translation of the PSC technology from laboratories to the market.
[1] W.-J. Chi, P.-P. Sun, Z.-S. Li, Nanoscale, 2016, 8, 17752.
[2] A. Magomedov, S. Paek et.al., Adv. Funct. Mater., 2018, 8, 1704351