Photosensitizers
1
Dye-Sensitized Solar Cells (DSCs)
DSCs have various fascinating properties, such as relatively low-toxic compounds, aesthetic colors, transparency, less sensitive to incident angle of sunlight and light intensity. These characteristics suggest that DSCs have significant advantages in building-integrated photovoltaics (BIPVs) compared to other kinds of photovoltaics, such as traditional silicon solar cells, perovskite, and organic photovoltaics. Recently, Grätzel et al. reported a power-conversion efficiency (PCE) of 15.2%, which is the highest PCE value in DSCs. To enhance PCE further, it is essential to develop photosensitizers possessing efficient charge transfer properties and absorbing near-infrared (NIR) regions.
My research interest is to develop highly-efficient photosensitizers by molecular engineering. For the molecular design of photosensitizers, their electronic properties, including energy levels, light harvesting ability, charge transfer, intramolecular, and intermolecular interactions, should be considered comprehensively. I modulated the electronic coupling of photosensitizers using conformational effects to enhance charge transfer into TiO2 and suppress charge recombination processes. I’m currently developing fused π-conjugated cores unit by controlling their aromaticity for enhancing light-harvesting (e.g., NIR regions) and charge transfer properties.
Aesthetic Colored DSCs
Building-Integrated Photovoltaic with DSCs
![DSCs - images [Edit].tif](https://static.wixstatic.com/media/db3762_edd334cb086a4213a45e979f6edc5ada~mv2.png/v1/fill/w_53,h_29,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/DSCs%20-%20images%20%5BEdit%5D_tif.png)
Schematic of DSCs
Working Principle of DSCs
Molecular-Design Strategy of Photosensitizers for DSCs
Electronic Coupling Engineering for Vectorial Electron Transfer
Chem 2022, 8, 1121
Resonance Raman Spectroscopic Study on Charge Transfer
Mat. Today Adv. 2022, 12, 100180
Controlling π-Spacer for Suppressing Charge Recombination
J. Phys. Chem. C 2016, 120, 24655
2
Dye-Sensitized Photoelectrochemical Cells (DSPECs)
Recalling, the DSCs are intrinsically photoelectrochemical cells. Thus, dye-sensitized systems can convert not only solar energy into electricity but also directly into storable solar fuels. DSPECs have focused mainly on water splitting in aqueous solution for several decades to produce eco-friendly hydrogen. However, the low quantum yields and insufficient stability of DSPECs in aqueous phase are huge hurdles. These limitations can be circumvented by replacing water-splitting reactions in the aqueous phase with organic reactions in non-aqueous phases, such as upcycling lignin, as demonstrated by Leem et al. recently reported several papers.
My research interest is molecular engineering of photosensitizers for enhancing the stability and performance of non-aqueous DSPECs. Furthermore, I'm currently utilizing the DSPECs in synthetic photoelectrochemistry for converting chemical wastes (e.g., lignin and CO2) into valuable aromatic compounds.
Non-aqueous DSPECs for Upcycling of Lignin