A fleeting photoinduced electronic state and the subsequent formation of a photoinduced hidden state in a metal–organic framework were captured in just 30 femtoseconds by researchers at Science Tokyo, Tohoku University and Nagoya Institute of Technology, Japan. By combining ultrafast laser spectroscopy with theoretical analysis, the researchers found that a transient electronic state plays a key role in this process. The findings provide new insights into controlling material properties with light for future applications.
When materials absorb light, they can enter unusual states with properties that differ from their normal behavior. These photoinduced states offer scientists a way to control material properties beyond what can be achieved through heating or cooling. Understanding how such states emerge on ultrafast timescales is essential for designing future photoresponsive materials and advanced optical technologies.
However, the earliest stages of photoinduced state formation can occur on the femtosecond (fs) timescale (a millionth of a billionth of a second), making it extremely difficult to observe and understand the process. To overcome this, a research team led by Assistant Professor Tadahiko Ishikawa from the Department of Chemistry, School of Science, Institute of Science Tokyo (Science Tokyo), Japan, along with doctoral student Samiran Banu (currently a Special Postdoctoral Researcher at RIKEN), conducted a study in collaboration with researchers from Tohoku University and Nagoya Institute of Technology, Japan.