Professor

Shigefusa Chichibu

Associate Professor

Kohei Shima

Design and creation of wide bandgap semiconductor quantum nanostructures and spatiotime-resolved spectroscopy

Research objectives of the laboratory are to design and create quantum nanostructures desirable for new functional optoelectronic devices workable in deep ultraviolet, visible, and optical communication wavelengths using planetconscious wide bandgap semiconductors, namely (Al,In,Ga)N and (Mg,Zn)O systems. We are growing quantum structures by metalorganic vapor phase epitaxy and unique helicon-wave-excited-plasma sputtering epitaxy methods. Ultrafast recombination dynamics of excited particles in nanostructures are studied by time-resolved spectroscopy using a femtosecond laser, and very local carrier dynamics are proved by focused pulsed electron beams using a homemade, spatio-time-resolved cathodoluminescence system equipped with a photoelectron-gun.

Themes

• A new concept coherent light source based on light-matter coupling in environment-friendly (B,Al,Ga,In)N and (Mg,Zn)O wide bandgap semiconductor microcavities
• Spatio-time-resolved spectroscopy in semiconductor materials
• Design and fabrication of (B,Al,Ga,In)N quantum nanostructures: epitaxial growths by metalorganic vapor phase epitaxy
• Helicon-wave-excited-plasma sputtering epitaxy of II-oxide semiconductor(Mg,Zn)O and fabrication of multifunctional oxide thin films