Improving the conductivity of sol–gel derived NiOx with a mixed oxide composite to realize over 80% fill factor in inverted planar perovskite solar cells. Issue 16 (29th January 2019)

• Record Type: Journal Article
• Authors: Li, Menglin; Xu, Xiuwen; Xie, Yuemin; Li, Ho-Wa; Ma, Yuhui; Cheng, Yuanhang; Tsang, Sai-Wing
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 16(2019)
• Page Start: 9578
• Page End: 9586
• Publication Date: 2019-01-29
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta10821h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : We demonstrated highly efficient and stable perovskite solar cells based on a NiO x :rGO oxide composite as the hole transport layer. Abstract : Charge extraction efficiency is one of the key factors to determine the performance of solar cells, which depends on the electronic properties of the electron and hole transporting layers. Sol–gel derived NiO x as the hole transporting layer (HTL) used in perovskite solar cells (PVSCs) promises both low-cost and high-stability. However, current NiO x based PVSCs have a relatively low fill factor (FF) and device efficiency. Here, we show that using an oxide composite approach by incorporating thermally reduced graphene oxide (rGO) into the NiO x layer (NiO x :rGO) can effectively improve the film conductivity without sacrificing its high work function. The improved charge extraction efficiency reduces the interfacial recombination loss and increases the carrier lifetime in NiO x :rGO based PVSCs, which are evidenced by transient photocurrent and transient photovoltage measurements. The NiO x :rGO based PVSC achieves a promising PCE of 19.1% with a significantly improved FF from 73% to 81% compared to the device using solely NiO x . Moreover, the NiO x :rGO based PVSC shows a decent photo-stability tracked at the maximum-power-point and a long shelf-lifetime with negligible degradation in device performance after 70 days. It is believed that the oxide composite transporting layer would be a promising alternative to further develop highly efficient and stable PVSCs.