| 研究実績の概要 |
1. We demonstrated that the length of hydrophilic blocks in amphiphilic semiconducting copolymers can control the morphology and stability of water-dispersed nanoparticles used in eco-friendly organic solar cells (OSCs). In particular, short insulating poly(4-vinylpyridine) blocks (~ 3 repeating units) lead to more stable dispersions but the best photovoltaic performances are obtained with slightly longer blocks (~ 5 units) that promote aggregation of conjugated moieties through hydrophobic interactions.
2. We fabricated nano- and microstructured thin films by phase separation in polymer blends. We integrated these low-cost self-assembled structures into OSC architectures that produced a 10% increase in OSC performances.
3. Using natural dyes (carotenoids) that can be extracted from vegetables through eco-friendly processes as active materials, we produced OSCs with efficiencies 4 times higher than previous reports on similar devices.
4. We produced OSCs using a low-cost green process with power conversion efficiencies (PCEs) of 5.8%. The PCE is the same as conventional spin-coated OSCs but the amount of hazardous solvent and costly material is reduced by a factor of 20 or more. The low-cost and green thin active layers can also be integrated as large scale semitransparent photovoltaic windows (PVWs) with PCEs over 4% and a slight purple color.
5. We fabricated PVWs based on active materials with complementary visible light absorption with PCE over 4% and transparency around 40%. The light transmitted through these PVWs does not change color (color rendering index over 95).
|
