Prof Grätzel has worked closely with Han Group (Prof Hongwei Han) for many years. In 2014 both teams (Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China and EPFL developed the hole-conductor–free, fully printable mesoscopic perovskite solar cell, currently the one with the highest stability and the most potential to be commercialized. In 2016 Prof Hongwei Han set up WonderSolar Co. Ltd. .
http://www.wondersolar.cn/nd.jsp?id=10#_np=2_802happyman
