The Effect of a Sol-gel Formed TiO₂Blocking Layer on the Efficiency of Dye-sensitized Solar Cells

Abstract

The effect of a dense TiO 2 blocking layer prepared using the sol-gel method on the performance of dyesensitized solar cells was studied. The blocking layer formed directly on the working electrode, separated it from the electrolyte, and prevented the back transfer of electrons from the electrode to the electrolyte. The dyesensitized solar cells were prepared with a working electrode of fluorine-doped tin oxide glass coated with a blocking layer of dense TiO 2 , a dye-attached mesoporous TiO 2 film, and a nano-gel electrolyte, and a counter electrode of Pt-deposited FTO glass. The gel processing conditions and heat treatment temperature for blocking layer formation affected the morphology and performance of the cells, and their optimal values were determined. The introduction of the blocking layer increased the conversion efficiency of the cell by 7.37% for the cell without a blocking layer to 8.55% for the cell with a dense TiO 2 blocking layer, under standard illumination conditions. The short-circuit current density (J sc ) and open-circuit voltage (V oc ) also were increased by the addition of a dense TiO 2 blocking layer.

A novel 2,7-diaminofluorene-based organic dye for a dye-sensitized solar cell

“…The cell with only DMPII, i.e., without any LiI shows the highest value of 0.80 V; however, the cell efficiency is not the highest in this case, because of its lowest J SC (8.00 mA cm À2 ), which was probably caused by a slow diffusion of DMPII ions in the electrolyte due to their large cation size. The large size of DMPII results in a low mass transfer rate of DMPI þ ions in the electrolyte, which in turn causes a small J SC for its cell [46,47]. On the other hand, higher J SC is observed with higher concentration of LiI, which is apparently due to faster diffusion of Li þ ions in the electrolyte, which in turn is due to its small size; however, the V OC decreases with increase in the concentration of Li þ , because the potential of TiO 2 conduction band shifts positively due to the positive charge of Li þ ions adsorbing on the TiO 2 surface [48,49].…”

Investigating the effect of molar ratio between TiO2 nanoparticles and titanium alkoxide in Pechini based TiO2 paste on photovoltaic performance of dye-sensitized solar cells

“…In recent years, dye-sensitized solar cells (DSSCs) have attracted considerable attention, because of their potentially high conversion efficiency, easy fabrication process and low production cost [1]. Photoanode is one of the most important components of DSSCs, which composed of a dye sensitized meso-porous semiconductor layer on a transparent conducting oxide (TCO) glass.…”

Titanium oxide hollow structure layer for dye sensitized solar cell by liquid phase deposition

“…Investigators have utilized via sputter deposition [7,8], spray pyrolysis [9], sol-gel method [10,11], and liquid phase deposition (LPD) [12] to prepare TiO 2 compact layers in an attempt to passivate the TCO surface [13].…”