Effects of TiCl₄ Treatment of Nanoporous TiO₂ Films on Morphology, Light Harvesting, and Charge-Carrier Dynamics in Dye-Sensitized Solar Cells

Abstract

We report on the effects of treating TiO 2 nanocrystalline films with different concentrations of TiCl 4 (5−500 mM) on the film morphology, chargecarrier dynamics, and performance of dye-sensitized solar cells. Transport and recombination in the TiCl 4 -treated films were studied by frequency-resolved modulated photocurrent/photovoltage spectroscopies. These studies showed that, at a low TiCl 4 concentration (5 mM), the electron diffusion coefficient in the annealed film increased. At intermediate TiCl 4 concentrations (15−50 mM), the surface area of the films increased, resulting in an increase of light harvesting and overall power conversion efficiency. At a high TiCl 4 concentration (500 mM), light scattering in the film in the long wavelength region of the visible spectrum was enhanced, but the averaged pore size of the film became narrower, resulting in slower transport and loss of cell performance.

Impact of a Mesoporous Titania–Perovskite Interface on the Performance of Hybrid Organic–Inorganic Perovskite Solar Cells

“…In DSSC, TiCl 4 -treatment of mp-TiO 2 electrode prior to the device fabrication improves the performance of the photovoltaic devices 22 , because of several phenomena, such as an increase in the electron injection rate, a retardation of the electron-hole recombination and/or an increase in the dye loading. However, the exact mechanism of the improvement is not clearly understood 23 .…”

Improvement of Light-Harvesting Efficiency of TiO2Granules Through Chemical Interconnection of Nanoparticles by Adding TEOT to Spray Solution

“…In addition, the use of submicron-sized TiO 2 beads generates voids, helping for the electrolyte to permeate well into the porous photoanode. TiCl 4 treatment is also known as an effective way to improve the cell efficiency because it results in the increase of electron lifetimes as the result of better connections between nanoparticles in photoanodes [14][15][16]. Given these results reported previously, the direct formation of chemical interconnection between nanoparticles at the preparation step of granules is expected to be beneficial for improving the efficiency of DSSCs.…”

Study on Antibacterial Activity of Ag Nanometal-deposited TiO2Prepared by Sonochemical Reduction Method

“…따라서 나노사이즈의 귀금속을 도핑하게 되면 광흡수도를 높이 고 전자-홀 쌍의 재결합속도를 감소시킴으로써 광촉매 기능의 향상을 이룰 수 있다 [4]. 이산화티탄 나노입자 표면에 자체 항균성이 있는 Ag 를 나노사이즈로 도핑하게 되면 광기능성 및 항균효과가 증진되어, 자외선차단, 항균효과, 청정 분해기능이 향상된 다양한 응용분야(항균 필터, 화장품 첨가제, 광촉매소재, 전극소재)에 적용이 가능하다 [5][6][7].…”