Prof Makoto KONAGAI

Prof Makoto KONAGAI

Tokyo City University, Japan

Major Research Accomplishment in 5 Years of "FUTURE -PV Innovation" Project”

The author's group is currently developing methods to dramatically improve efficiency of solar cells using existing Si technology. Started in July 2012, the "FUTURE -PV Innovation" project is underway as a 5-year project in Koriyama City, Fukushima Prefecture. The current conversion efficiency of Si solar cells is restricted by the Si energy bandgap (Eg = 1.1 eV). The optimum energy bandgap for converting solar energy into electricity is approximately 1.5 eV. In the FUTURE-PV Innovation project, the  energy bandgap of Si will be controlled to around 1.3-1.7 eV using the quantum confinement effect, which will be obtained using an Si nanowire/wall  structure. According to theoretical analysis, it will be possible to obtain an energy bandgap of 1.3-1.7 eV if an extremely fine wire/wall of several nm diameter/width can be produced. Further, the project aims to achieve an energy conversion efficiency exceeding 30% by preparing a tandem solar cell using a waidegap nanowire/wall solar cell and a Si heterojunction solar cell.  The research is being implemented using a system known as an industry-university consortium. The research system consists of three teams; Team 1: Super-high-quality Si crystal technology, Team 2: Fabrication process for silicon nanowire/wall and characterization, Team 3:  Nanowire/wall solar cells.  In the presentation, research targets and recent major accomplishment will be demonstrated. 



Makoto KONAGAI is Professor at Tokyo City University. He received the B.E., M.E and D.E degrees in Electronic Engineering from Tokyo Institute of Technology in 1972, 1974 and 1977, respectively.  Since 1977, he has been with Tokyo Institute of Technology, where he has been engaged in the development of solar cell materials and devices.  He retired Tokyo Institute of Technology on March 2015 and has been working for Tokyo City University since April 2015.

He is currently working on bulk and thin-film Si Si solar cells.  He has authored over 400 publications in international journals and over 500 international presentations.

  He organized PVSEC-9 (1996) and WCPEC-6(2014).  He is currently the chairman of JSPS, The 175th Committee on Innovative Photovoltaic Power Generation Systems and the chairman of International Advisory Committee of PVSEC.

He has received prestigious awards, including the PVSEC Award (1999), Medal with Purple Ribbon (2013) and Hamakawa Award(2014).  He is now a member of Science Council of Japan.