Enhanced performance of dye-sensitized solar cells based on TiO₂nanotube membranes using an optimized annealing profile

Abstract

We use free-standing TiO2 nanotube membranes that are transferred onto FTO slides in front-side illuminated dye-sensitized solar cells (DSSCs). We investigate the key parameters for solar cell arrangement of self-ordered anodic TiO2 nanotube layers on the FTO substrate, namely the influence of the annealing procedure on the DSSC light conversion efficiency. The results show that using an optimal temperature annealing profile can significantly enhance the DSSC efficiency (in our case η = 9.8%), as it leads to a markedly lower density of trapping states in the tube oxide, and thus to strongly improved electron transport properties.

Stable and Efficient Perovskite Solar Cells Based on Titania Nanotube Arrays

“…Compared to nanoparticle films, highly ordered and strongly interconnected arrays of 1D architectures, such as nanowires, nanorods and nanotubes, can eliminate the drawbacks that arise from the randomization of the grain network . In such highly ordered structures, the photoinjected electrons can find a direct path, which could increase the charge collection and avoid unnecessary electron–hole recombination . Xu and co‐workers fabricated rutile TiO 2 nanowire‐based perovskite solar cells, showing a PCE of 11.7% .…”

Free‐Standing Membranes to Study the Optical Properties of Anodic TiO2 Nanotube Layers

“…After anodization, the samples are treated in a 30 % H 2 O 2 aqueous solution at room temperature for ca. 3 h. Owing to the higher chemical stability of the upper anodic layer, this treatment leads to the chemical dissolution of the lower tube layer, so that the upper one is detached from the substrate as entire self‐standing TiO 2 nanotube membrane …”

“…TiO 2 , having bandgap of ∼3.2 eV in the anatase form and of ∼3.0 eV in the rutile form, is widely explored as a photocatalyst for water splitting, since valence band holes and conduction band electrons generated upon super‐bandgap irradiation are able to oxidize and reduce water into O 2 and H 2 , respectively . In addition, owing to the relatively high electron mobility of TiO 2 , TiO 2 scaffolds have found wide application as anodes for photo‐electrochemical (PEC) water splitting, and for dye‐sensitized solar cells (DSSCs) …”

Double-layer TiO2 nanotube arrays by two-step anodization: Used in back and front-side illuminated dye-sensitized solar cells

“…The detached upper-layer was an intact membrane. This membrane with length of 20 mm (for this purpose the first anodization was done for 40 min) was transferred on coated FTO glass with 2 mm nanoparticle paste (Ti-Nanoxide HT, Solaronix) and after crystallization at 500 1C with heating and cooling rate of 30 1C min À 1 used in frontside illuminated DSSCs [1]. Also, the remained TiO 2 nanotube layers on Ti foil were used to make back-side illuminated DSSCs.…”

“…Over the past decade TiO 2 nanotubes have been widely used as photoanode in dye-sensitized solar cells (DSSCs) [1][2][3][4]. Highly ordered geometry [5,6], promising optical and electronic properties [7][8][9] and one dimensional direction of electron movements [10,11] make them a good candidate for this purpose.…”