Efficient quasi-solid dye sensitized solar cells employing molten salt electrolyte

Abstract

There have been many attempts to increase the overall conversion efficiency of dye-sensitized solar cells using liquid-state electrolytes. However, this type of cells have unsolved critical problems such as leakage and evaporation of volatile organic solvents. Thus the development of more stable solid or quasi-solid state cell is of great importance. In the study reported here, we developed a novel fabrication method of dye sensitized quasi-solid solar cells using solid composite materials of LiSCN and methyl-hexyl-imidazolium iodide (MHImI) as hole transport materials to replace liquid iodide and polyiodide electrolyte which consists of volatile solvents. The device based on 6 µm thick nanocrystalline TiO 2 film absorbed by monolayer of Ru(II) terpyridyl complex photosensitizer (N719 dye), shows excellent incident photon-to-electron conversion efficiency (IPCE, ~ 75%) , large current density (11.6 mA cm -2 ), and high light-to-electric energy conversion efficiency (5.3-6.1%) under the illumination of 100 mW cm -2 (AM 1.5).

The potential of incorporation of binary salts and ionic liquid in P(VP-co-VAc) gel polymer electrolyte in electrochemical and photovoltaic performances

“…This is most probably the reason for the increase in photovoltaic efficiencies of the DSSCs. This increment can be recognized due to the larger number of the diffusion coefficient of triiodide rendering the dye molecule to be able to regenerate more easily resulting in lower recombination rate which leads to increase of J sc 57 58 59 . Normally, the charge transport mechanism in the polymer electrolyte of the DSSCs can be interpreted as Grotthus mechanism which is also known as the electron hopping and ion exchange 60 61 62 .…”

Polymer electrolytes based PAN for dye-sensitized solar cells

“…It was notified that the adsorption of cations such as Li + , Na + , TBA + and Mg 2+ into a polycrystalline TiO 2 electrode are significant not only in fixing the flat band potential of the electrode but also in the designation of electron diffusion coefficients of the mesoporous electrodes. The lithium salt could screen the field caused by space charge created under illumination of the heterojunction leading to inhibition of charge recombination and then to the increase of photo-generated electron on TiO 2 [17]. The varied short circuit current density is because of the enhanced ionic conductivity of the polymer electrolytes.…”