Array of solid-state dye-sensitized solar cells with micropatterned TiO2 nanoparticles for a high-voltage power source

Improvement in Energy Conversion Efficiency by Modification of Photon Distribution within the Photoanode of Dye-Sensitized Solar Cells

The dye-sensitized solar cell (DSSC) is a potential alternative to the widely used Si-based solar cell, with several advantages including higher energy conversion efficiency under weak and indirect illumination conditions, and the possibility of practical application in urban life due to their exterior characteristics. However, despite these advantages, the energy conversion efficiency of DSSCs has remained low at ∼10%. To improve the efficiency of DSSCs, research has been done on modifying the materials used in DSSC component parts, such as the photoanode, electrolyte, and counter electrode. Another approach is to modify the photoanode to increase the diffusion coefficient, reduce the recombination rate, and enhance the light behavior. One of the most popular methods for improving the efficiency of DSSCs is by trapping and dispersing the incident light using a scattering layer. Use of a scattering layer has shown various and interesting results, depending on the application, but it is currently used only in a simple form and there has been no deep research on the further potential of the scattering layer. In this study, the scattering center was introduced to maximize the effect of scattering. Light distribution near the scattering center, within or on the photoanode, was investigated using finite differential time domain (FDTD) numerical methods. Based on the FDTD analysis, an optimized, dome-shaped three-dimensional modified structure of a transparent photoanode with minimized scattering centers was introduced and indicated the possibility of modifying the photon distribution in the photoanode to enhance the performance of DSSCs. In addition to using the scattering center, we have introduced the structure of the dome-shaped three-dimensional structure to utilize the light distribution within the photoanode. This novel three-dimensional transparent photoanode and scattering center design increased the energy conversion efficiency of DSSCs from 6.3 to 7.2%. These results provide a foundation for investigating the role of the scattering center via further in-depth research. This new three-dimensional photoanode design provides a means to overcome the previous limitations on DSSC performance.

Micropatterned arrays of functional materials by self-organized dewetting of ultrathin polymer films combined with electrodeposition

Directed dewetting of polymer films is established as a viable large area patterning tool for selective growth of functional oxides.

Self-powered ion detectors based on dye-sensitized photovoltaics

Autonomous sensing of metal ion contamination in remote environments with high reproducibility and sensitivity could unlock many new applications, but involves trade-offs between compactness, sensitivity, and power provisioning. In prior demonstrations of semi-autonomous sensors, the power source (e.g. a solar cell) was an additional component. Here, we demonstrate a concept, wherein a dye-sensitized solar cell is used for both power generation and sensitive detection of ionic analytes, unlocking a new pathway for ultra-miniaturization and integration.