Kyushu University: Highly efficient conversion of visible light to ultraviolet light: 20% conversion efficiency
-Molecular material that achieves conversion efficiency of over 20% without using heavy metals-
January 14, 2022
Hydrogen production by sunlight:
“To improve the efficiency of hydrogen production by sunlight, it is necessary to use ultraviolet light with high energy.”
However, “most of the sunlight is visible light or near-infrared light” and the intensity is weak.
Therefore, a conversion system that works with low excitation light intensity is required.
Kyushu University Graduate School
Associate Professor Nobuhiro Yangi
To improve the efficiency of hydrogen fuel production and environmental purification using photocatalysts
Without using heavy metals
Highly efficient conversion of visible light to ultraviolet light,
Developed a molecular material.
The conversion efficiency, which was about 8.2% in the past, has been increased to 20.3%.
It can be applied to an environment-friendly solar hydrogen production system at low cost.
Focus on ketocumarin derivatives:
Shows strong visible light absorption,
Happens between different quantum states
Moreover, the efficiency of intersystem crossing is high.
We focused on ketocumarin derivatives.
Combine acceptor molecules:
From ketocoumarin derivatives
Receives energy and emits light in the ultraviolet region,
The acceptor molecule was combined.
By combining acceptor molecules, the excitation light intensity required for conversion was reduced to several tens of mw per square cm.
Highly efficient conversion of visible light to ultraviolet light:
In the past, visible light that was about 1000 times stronger than sunlight was required.
This time, we were able to convert visible light to ultraviolet light with the same weak intensity as sunlight.
New switch