Polyoxometalate-Based Inorganic–Organic Hybrid [Cu(phen)₂]₂[(α-Mo₈O₂₆)]: A New Additive to Spiro-OMeTAD for Efficient and Stable Perovskite Solar Cells

Abstract

It is quite meaningful for improving the properties of Spiro-OMeTAD-based hole transport materials (HTMs) to realize high-efficiency and stable perovskite solar cells. In this work, a polyoxometalate (POM)-based inorganic−organic hybrid [Cu(phen) 2 ] 2 [(α-Mo 8 O 26 )](CMP) with strong electron-accepting properties was successfully synthesized and for the first time introduced into Spiro-OMeTAD to achieve quantitative and controllable oxidation of Spiro-OMeTAD, which presents obviously increased conductivity in comparison to its counterpart. Accordingly, the corresponding perovskite solar cells' (PSCs) performance shows a substantial improvement. The optimal device achieves a power conversion efficiency (PCE) as high as 18.72%, which is higher than that of the ever-reported POMs-based PSCs. Meanwhile, CMP-based PSCs also show long-term stability. This work provides a feasible and efficient approach for further development of PSCs.

Application of polyoxometalates in third-generation solar cells

“…In 2019, Yang et al synthesized an inorganic-organic hybrid [Cu(phen)2]2[(α-Mo8O26)] (CMP) with strong electron acceptance and incorporated it into Spiro-Ome TAD for the first time to achieve quantitative controlled oxidation of Spiro-Ome TAD, which showed superior conductivity compared with the counterpart. 109 Accordingly, the PSC based on the CMP additive expressed an unprecedented increase in conductivity and charge extraction performance, which resulted in significant improvements in FF, Voc and PCE. The modified PSC can achieve a maximum PCE of 18.72%, which is much higher than the previously reported POM-based PSCs.…”

Current advancements on charge selective contact interfacial layers and electrodes in flexible hybrid perovskite photovoltaics

“…For example, polyoxometalates (POMs) are promising 3D metal oxide-based inorganic materials with versatile shape/size and several desirable physicochemical and photophysical properties that can be explored in a wide range of applications. Previous reports utilize POMs as a cost-effective standalone interface (injection/transport/scaffold) layer in optoelectronic applications (polymer/PSCs, light-emitting diodes and photodetectors) [273][274][275][276][277][278][279]. Therefore, more research should be carried out in this direction as they have significant potential with the multifunctional capabilities of the materials.…”

Application of Metal-Organic Frameworks and Covalent Organic Frameworks as (Photo)Active Material in Hybrid Photovoltaic Technologies

“…They tested a hybrid polyoxometalate@metal-organic framework (POM@MOF) material, [Cu 2 (BTC)4/3-(H 2 O) 2 ] 6 [H 3 PMo 12 O 40 ] 2 for the oxidation of spiro-OMeTAD with Li-TFSI and TBP. POMs began to attract attentions in PSCs, owing to their strong electron-accepting and oxidation ability, [236] being able to oxidize spiro-OMeTAD in an inert condition, and increase conductivity and performance of device [237]. In this context, POM@Cu-BTC composite showed dual-functions during chemical doping spiro-OMeTAD increasing the hole mobility of the resulting HTM by a factor of 2 and an overall PCE close to 22%.…”