Dye-sensitized solar cells consistently provide a cost-effective avenue for sources of renewable energy, primarily due to their unique utilization of nanoporous semiconductors. Through mathematical modelling, we are able to uncover insights into electron transport to optimize the operating efficiency of the dye-sensitized solar cells. In particular, fractional diffusion equations create a link between electron density and porosity of the nanoporous semiconductors. We numerically solve a fractional diffusion model using a finite-difference method and a finite-element method to discretize space and an implicit finite-difference method to discretize time. Finally, we calculate the accuracy of each method by evaluating the numerical errors under grid refinement.

Two phases of nickel sulfide (α-NiS and β-NiS) nanoarchitectures were successfully and controllably synthesized by a facile solvothermal method with two different solvents of alcohol and water, respectively. The products were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-vis diffuse reflectance spectrophotometer. The sphere-like shape for α-NiS and cross-like shape composed of nanorods for β-NiS are uniform and well distributed as well as their size. Both α-NiS and β-NiS powders were used as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). It is found that the DSSC with an α-NiS CE performs much better than the one with a β-NiS CE. The energy conversion efficiency of the former was 5.2%, whereas the latter was 4.2%, about 20% increment.

Nanosized anatase TiO2 nanosheets with highly exposed reactive {001} facets (∼80%) were prepared via hydrothermal reaction with the addition of hydrofluoric acid and characterized by various techniques including transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller. High-quality TiO2 nanosheets films with different thicknesses (∼5–20 μm) were fabricated by doctor blading, and the effect of film thickness on the performance of dye-sensitized solar cells (DSSCs) was investigated by I-V characterization and dark current potential scan. The results show that each parameter of DSSCs performance depends strongly on the thickness of the TiO2 nanosheets films. An optimized DSSCs performance of 8.39% was obtained by the TiO2nanosheets film with a thickness of ∼15 μm.

The dye-sensitized solar cell (DSSC) provides a technically and economically viable alternative concept to present-day p–n junction photovoltaic devices. In contrast to conventional silicon systems, where the semiconductor assumes both the task of light absorption and charge carrier transport, these two functions are separated in DSSCs. The use of sensitizers having a broad absorption band in conjunction with wide-bandgap semiconductor films of mesoporous or nanocrystalline morphology permits harvesting a large fraction of sunlight. There are good prospects that these devices can attain the conversion efficiency of liquid-electrolyte-based dye-sensitized solar cells, which currently stands at 11%. In this article, we present the current state of the field, the realm of our review being restricted to the discussion of organic molecular hole conductors, which have demonstrated the best performance to date.