光励起キャリアダイナミクスに対する拡散異方性、混合、界面の効果

抄録

The effect of diffusion on photoexcited carrier kinetics has been studied for decades. However, many difficult issues remain unresolved. For example, when the concentration of photoexcited carriers is high, diffusive mixing of photoexcited carriers proceeds with time. Immediately after pulsed excitation, the photoexcited carriers are expected to interact with their nearest neighbour carriers, and as time passes, diffusive mixing proceeds and free carriers are generated. The delayed fluorescence due to triplet-triplet annihilation (TTA) in organic solids are reviewed, followed by recent results on diffusive mixing. We also present recent results on bulk reactions of electrons and holes in particulate photocatalysts. The bulk reactions of carriers in semiconductors are well studied by using the semiconductor equations. However, for particulate photocatalysts, boundary conditions at the interface with water need to be considered. The quantum yield of photocatalysts under solar irradiation is discussed.