PtSe2 outperforms Pt as a counter electrode in dye sensitized solar cells

In the present study, we show that PtSe2 films, prepared by soft selenization of pre-deposited Pt, is a very efficient counter electrode (CE) in dye sensitized solar cells (DSSCs). Devices based on PtSe2 achieve better photoconversion efficiency (9.5 & PLUSMN; 1.2%) than those employing bare Pt CE (9.18 & PLUSMN; 0.21%), even if the latter use three times more Pt loading than that used to prepare the PtSe2 CE. Films with of various Pt loadings have been prepared by electrodeposition and their catalytic properties have been investigated and compared with films of corresponding Pt loading which have been transformed to PtSe2 by low-temperature selenization. The improved performance of the PtSe2 CEs has been assigned to the higher availability of catalytic active sites and the more effective mechanism of interfacial electron transfer. This is a first attempt to explore the role of PtSe2 as the CE in DSSCs. The strong advantages of PtSe2 in relation to catalytic activity, stability, efficiency, combined with cost reduction, due to the lower mass loading required for a given performance, renders this noble-transition metal dichalcogenide a promising candidate to boost the performance of third generation photovoltaics, opening-up possibilities, at the same time, for other applications where Pt is used as the catalyst.