2H-NbS2 film as a novel counter electrode for meso-structured perovskite solar cells

Feng Shao,Li Xu,Fuqiang Huang,Peng Qin,Wei Zhao,Deliang Wang,Zhangliu Tian,Kejun Bu

doi:10.1038/s41598-018-25449-x

Abstract

We report the use of 2H-NbS2 film as a novel counter electrode in perovskite solar cells fabricated with a cold isostatic pressing method. The 2H-NbS2 film, which was prepared through an exfoliation method followed by restacking from LixNbS2 powder, shows high electrical conductivity of 8.7 × 103 S cm−1 and work function of 5.20 eV. The two-dimensional transition metal dichalcogenide was used for the first time as a counter electrode in meso-structured perovskite solar cells. Through this process, we demonstrated a new alternative to noble metals. The perovskite solar cell base on the 2H-NbS2 counter electrode showed an open-circuit voltage of 1.046 V, comparable to that of gold, and a power conversion efficiency of 8.3%.

Highlights

Perovskite solar cells (PSCs) have been intensively investigated as a promising candidate for the low cost photovoltaic technology since the first report by Miyasaka et al in 20091
NbS2 powder was firstly synthesized through the conventional solid-state reaction (SSR) from Nb and S34
Exfoliation of the LixNbS2 in hydrochloric acid aqueous solution led to the exchange of Li+ with H+, forming a homogeneous NbS2 nanosheet colloid

Summary

Results and Discussion

The cold isostatic pressing method was firstly used to combine the prepared NbS2 film over the organic hole transporting layer for the preparation of perovskite solar cells Based on this new counter electrode, the device showed a power conversion efficiency of 8.3% in our tests, and a comparable Voc (1046 mV) comparing with that of gold. The two-dimensional transition metal dichalcogenide film is used as a counter electrode in perovskite solar cells, avoiding the conventional use of expensive noble metals and the high-energy consuming thermal evaporation process Both the TMD materials and the isostatic pressing technique need to be further optimized to improve the performance, this method provides an alternative way for the selection of new type of electrodes for the photovoltaic devices. (d) Degradation of PCE of the unencapsulated two best-performed devices under the ambient condition at room temperature (24 °C)

Methods

Author Contributions

Additional Information