Electrochemical characterization of TiO2 blocking layers prepared by reactive DC magnetron sputtering

Abstract

This is an author produced version of a paper published in Journal of Electroanalytical Chemistry. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination. AbstractThin TiO 2 (anatase) films were prepared by reactive DC magnetron sputtering and characterized in detail. Specifically, they were tested as compact blocking underlayers in dye-sensitized solar cells. Elastic recoil detection analysis and optical measurement showed some porosity in the sputtered films, but electrochemical measurements demonstrated good blocking characteristics. This suggests the presence of small voids rather than pinholes in the deposited films. In the case of an iodide/iodine redox couple, thin underlayers (~20 nm) improved the fill factor without affecting other properties of 1 the cell. In case of a ferrocene / ferrocenium-based electrolyte, the presence of underlayers was necessary to obtain functional dye-sensitized solar cells.

Preparation of novel TiO 2 quantum dot blocking layers at conductive glass/TiO 2 interfaces for efficient CdS quantum dot sensitized solar cells

“…3 Table 1, the PCE of these cells are enhanced with the increased thickness of TiO 2 -QD-BLs to 641 nm, and both the open-circuit voltage (V oc ) and short-circuit current density (J sc ) are also increased, whereas the fill factor (FF) gradually decreased. The reason is that apart from the positive function of blocking dark recombination reaction, too thick TiO 2 -QD-BLs can also hinder electron transportation and decrease wetting ability of polysulfide electrolyte in the QDSSCs [21,22]. Fig.…”

Dye‐Sensitized Back‐Contact Solar Cells

“…The role of the iodide/triiodide redox mediator is to regenerate the dye, following electron injection and effectively transport positive charge away from the dye towards the counter electrode. The electrochemical reduction of triiodide to iodide on plain FTO glass is very inefficient due to high overpotentials 5. This has two important implications.…”

Blocking layers for nanocomposite photoanodes in dye sensitized solar cells: Comparison of atomic layer deposition and TiCl4 treatment

“…Blocking layers are widely used in DSSC to prevent recombination of the electron in the semiconductor or FTO with the electrolyte. Blocking layers are often thin insulating layers of TiO2 [6], ZnO [7,8], ZrO2 [9,10], SiO2 [9], Al2O3 [9,11], MgO [12,13], HfO2 [14], CdO [15], or polysiloxane [16] deposited on working electrode by various techniques like spray pyrolysis [17], sputtering [18], spin coating [19], dip coating [20], chemical vapor deposition [21], sol-gel deposition [9], TiCl4 treatment [6], chemical bath deposition [22] or atomic layer deposition [23]. The ideal blocking layer should cover the entire surface of the FTO and TiO2 to prevent recombination and should not prevent electron injection.…”