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

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 ([C(2)mim] I similar to 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 NH 4 SCN 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. (C) 2022 Published by Elsevier B.V.

Automated summary

The study investigated the effects of electrolyte solutions containing acetonitrile solvent and various salts on the performance of dye-sensitized solar cells (DSSCs). Experimental results showed that the DSSC exhibited high performance when a mixture of potassium iodide (KI) and 1-ethyl-3-methylimidazolium iodide ionic liquid (Emim-I) was used. Additionally, molecular dynamics simulations were conducted to study the interface of solid/liquid electrolytes, revealing the significant influence of cations on the density distribution of anions at the interface.