The use of 1-ethyl-3-methylimidazolium iodide ionic liquid in dye sensitized solar cells: A joint experimental and computational perspective

• Published in: Journal of molecular liquids 2022-10, Vol.364, p.119982, Article 119982
• Main Authors: Reza Zolghadr, Amin, Azari, Niloufar, Heydari Dokoohaki, Maryam
• Format: Article
• Language: English
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2022.119982

[Display omitted] •The influence of different electrolyte mixtures containing Emim-I ionic liquid on the performance of dye-sensitized solar cells were studied.•Some new thiocyanate additives (NaSCN and NH4SCN) were used to enhance the photovoltaic performance of DSSCs.•The structure and dynamics of electrolyte solutions confined between solid surfaces were investigated by using MD simulations. The photovoltaic performance of dye-sensitized solar cells (DSSCs) significantly depends on the components of electrolyte solution. In this study, the electrolytes involving acetonitrile (ACN) solvent and various salts namely potassium iodide (KI), 1-ethyl-3-methylimidazolium iodide ionic liquid ([C2mim]I ∼ Emim-I IL), sodium thiocyanate (NaSCN), and ammonium thiocyanate (NH4SCN) were fabricated and their effects on the DSSC performance were explored. Among the different inorganic (KI) and organic (Emim-I) iodide sources, the DSSC showed high performance when KI and Emim-I mixed. In the meantime, without KI, by increasing Emim-I concentration from 0.3 M to 1.2 M, the best efficiency of DSSC was obtained for 0.9 M concentration. The results indicated that the best performance of the cells can be obtained when Emim-I and NH4SCN were added to the 0.6 M of KI solution. Power conversion efficiency as high as 11.07 % was obtained under the best operation conditions. Beside experiments, the interface of solid/liquid electrolyte was also studied as a key element of DSSCs by using molecular dynamics simulations. The influence of cations such as K+, and 1-ethyl-3-methylimidazolium (Emim+), Na+, and NH4+ on the double-layer structure in ACN-based electrolytes at the anatase TiO2(101) and platinum surfaces was studied. Particularly, a strong impact of cations on the I− and SCN− anions density distribution at the interface was found.