Functionalization of SnO₂ photoanode through Mg-doping and TiO₂-coating to synergically boost dye-sensitized solar cell performance

Investigation of the structural and electrochemical properties of a ZnO–SnO2 composite and its electrical properties for application in dye-sensitized solar cells

This study compares photovoltaic and electrochemical properties of nano sized ZnO–SnO2 composite as photoanode material made by a simple but effective mechanical mixing method with Ru N719 dye for energy harvesting applications in DSSCs.

Eco-friendly synthesis of core-shell structured (TiO2/Li2CO3) nanomaterials for low cost dye-sensitized solar cells

Core-shell structured TiO₂/Li₂CO₃ electrode was successfully synthesized by eco-friendly solution growth technique. TiO₂/Li₂CO₃ electrodes were characterized using X-ray Diffractometer (XRD), Scanning electron microscopy (SEM) and photocurrent-voltage measurements. The synthesized core-shell electrode material was sensitized with tetrabutylammonium cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine)ruthenate(II) (N-719). The performance of dye-sensitized solar cells (DSCs) based on N719 dye modified TiO₂/Li₂CO₃ electrodes was investigated. The effect of various shell thickness on the photovoltaic performance of the core-shell structured electrode is also investigated. We found that Li₂CO₃ shells of all thicknesses perform as inert barriers which improve open-circuit voltage (V_oc) of the DSCs. The energy conversion efficiency was greatly dependent on the thickness of Li₂CO₃ on TiO₂ film, and the highest efficiency of 3.7% was achieved at the optimum Li₂CO₃ shell layer.

Engineered band structure for an enhanced performance on quantum dot-sensitized solar cells

A photon-to-current efficiency of 2.93% is received for the Mn-doped CdS (MCdS)-quantum dot sensitized solar cells (QDSSCs) using Mn:ZnO (MZnO) nanowire as photoanode. Hydrothermal synthesized MZnO are spin-coated on fluorine doped tin oxide (FTO) glass with P25 paste to serve as photoanode after calcinations. MCdS was deposited on the MZnO film by the successive ionic layer adsorption and reaction method. The long lived excitation energy state of Mn2+ is located inside the conduction band in the wide bandgap ZnO and under the conduction band of CdS, which increases the energetic overlap of donor and acceptor states, reducing the “loss-in-potential,” inhibiting charge recombination, and accelerating electron injection. The engineered band structure is well reflected by the electrochemical band detected using cyclic voltammetry. Cell performances are evidenced by current density-voltage (J-V) traces, diffuse reflectance spectra, transient PL spectroscopy, and incident photon to current conversion efficiency characterizations. Further coating of CdSe on MZnO/MCdS electrode expands the light absorption band of the sensitizer, an efficiency of 4.94% is received for QDSSCs.

Effects of Ga doping and hollow structure on the band-structures and photovoltaic properties of SnO2 photoanode dye-sensitized solar cells

By introducing the rough hollow microspheres structure and Ga-doping technique, a high power conversion efficiency (η) up to 7.11% is obtained for SnO₂ based DSSCs.

Preparation of rutile TiO(2) coating by thermal chemical vapor deposition for anticoking applications

To inhibit the metal catalytic coking and improve the oxidation resistance of TiN coating, rutile TiO2 coating has been directly designed as an efficient anticoking coating for n-hexane pyrolysis. TiO2 coatings were prepared on the inner surface of SS304 tubes by a thermal CVD method under varied temperatures from 650 to 900 °C. The rutile TiO2 coating was obtained by annealing the as-deposited TiO2 coating, which is an alternative route for the deposition of rutile TiO2 coating. The morphology, elemental and phase composition of TiO2 coatings were characterized by SEM, EDX and XRD, respectively. The results show that deposition temperature of TiO2 coatings has a strong effect on the morphology and thickness of as-deposited TiO2 coatings. Fe, Cr and Ni at.% of the substrate gradually changes to 0 when the temperature is increased to 800 °C. The thickness of TiO2 coating is more than 6 μm and uniform by metalloscopy, and the films have a nonstoichiometric composition of Ti3O8 when the deposition temperature is above 800 °C. The anticoking tests show that the TiO2 coating at a deposition temperature of 800 °C is sufficiently thick to cover the cracks and gaps on the surface of blank substrate and cut off the catalytic coke growth effect of the metal substrate. The anticoking ratio of TiO2 coating corresponding to each 5 cm segments is above 65% and the average anticoking ratio of TiO2 coating is up to 76%. Thus, the TiO2 coating can provide a very good protective layer to prevent the substrate from severe coking efficiently.

Quintuple-shelled SnO(2) hollow microspheres with superior light scattering for high-performance dye-sensitized solar cells

Quintuple-shelled SnO2 hollow microspheres are prepared by a hard-template method. DSSCs constructed with SnO2 multi-shell photoanodes show a record photoconversion efficiency of 7.18% due to enhanced light scattering. SnO2 hollow microspheres that are utilized as a scattering layer on top of P25 films increase the DSSC photoconversion efficiency from 7.29% to 9.53%.

Gallium-doped tin oxide nano-cuboids for improved dye sensitized solar cell

Tin dioxide (SnO2) is a potential candidate to replace conventional titanium dioxide (TiO2) in dye-sensitized solar cells (DSSCs) because of its wider bandgap and higher electron mobility. However, SnO2 suffers from low band edge that causes severe backflow of electrons towards electrolyte (charge recombination). Herein, we demonstrate that gallium (Ga) doping can increase the band edge of SnO2, and we show that DSSCs using a Ga-doped SnO2 nano-cuboids based photoanode offer improved open circuit potential (~0.74 V), fill factor (~73.7%), and power conversion efficiency (~4.05%).