THE DEVELOPMENT OF BIFACIAL DYE SENSITIZED SOLAR CELLS BASED ON BINARY IONIC LIQUID ELECTROLYTE

摘要

Dye sensitized solar cells (DSSC) have gained much interest in recent years due to its low cost,improved conversion efficiency and practical application methods. Most of the measurements of the efficiency ofdye sensitized solar cells are made in liquid electrolyte (I-/I_3- redox couple). Because, liquid electrolyte allowshigh electron mass transfer between dye and counter electrode and this also contributes to the efficiency. On theother hand, liquid electrolytes cause several problems to the system which are volatility of electrolyte, electrodecorrosion, difficulties in sealing and short time stability of the device. Recently, some work has been done toreplace liquid electrolytes with some solid systems. Solvent free ionic liquid electrolyte is shown to be a goodchoice for DSSC applications due to thermal stability, non-flammability, high ionic conductivity, negligiblevapour pressure and non-toxicity as solid state. However, solid structure decreases the electron transfer rate anddiffusion length; in other words, with this type of electrolyte, efficiency decreases considerably. This decreasecan be compensated by 4 different mechanisms. These are bifacial design, additional SiO_2 layer, thicknessoptimization of the semiconductor layer and using additional chemicals. In this work, TiO_2 will be used assemiconductor and it will be synthesized using related procedures as porous structures. 1-propyl 3-methylimidazolium iodide and 1-ethyl 3- methylimidazolium tetracyanoborate (PMII//(EMIB(CN)4)) electrolytewill be used as ionic liquid electrolyte.