Dr. Kai Zhu is a senior scientist in the Chemistry and Nanoscience Center at the National Renewable Energy Laboratory (NREL). He received his Ph.D. degree in Physics from Syracuse University in 2003, where he studied the electrical and optical properties and the device physics of solar cells based on amorphous-silicon thin films and dye-sensitized mesoporous TiO₂ films. He was then a postdoctoral researcher for about one year at Kansas State University, working on III-nitride wide-bandgap semiconductors for high-power blue and ultraviolet light-emitting diodes. In 2004, he joined NREL as a postdoctoral researcher in the laboratories of Dr. Arthur J. Frank, working on fundamental charge-carrier transport and recombination in photoelectrochemical cells, especially dye-sensitized solar cells. Since 2007, he has worked as a staff scientist at NREL.

Research Interests

• Current research interests are both basic and applied research on perovskite solar cells, including perovskite material development, device fabrication and characterization, and basic understanding of charge-carrier dynamics in these cells.
• Research interests have also included hydrogen production via photoelectrochemical cells and nanostructured electrodes for Li-ion batteries and supercapacitors.

Education

Ph.D. Physics, Syracuse University

M.S. Physics, University of Science & Technology of China

B.S. Physics, University of Science & Technology of China

Featured Work

Yang, M.; Li, Z.; Reese, M.O.; Reid, O.G.; Kim, D.H; Siol, S.; Klein, T.R.; Yan, Y.; Berry, J.J.; van Hest M.F.A.M.; Zhu, K., “Perovskite ink with wide processing window for scalable high-efficiency solar cells,” Nature Energy 2, 17038 (2017).

Guo, Z.; Wan, Y.; Yang, M. Snaider, J. Zhu, K.; Huang; L., “Long-range hot-carrier transport in hybrid perovskites visualized by ultrafast microscopy,” Science 356, 59 (2017).

Yang, Y.; Yang, M.; Moore, D.T.; Yan, Y.; Miller, E.M.; Zhu, K.; Beard, M.C., “Top and bottom surfaces limit carrier lifetime in lead iodide perovskite films,” Nature Energy 2, 16207 (2017).

Li, Z.; Xiao, C.; Yang, Y; Harvey, S.P.; Kim, D.H.; Christians, J.A.; Yang M.; Schulz, P.; Nanayakkara, S.U.; Jiang, C.-S. Luther, J.M.; Berry, J.J., Beard, M.C.; Al-Jassim, M.M.; Zhu, K., “Extrinsic ion migration in perovskite solar cells,” Energy Environ. Sci. (2017), DOI: 10.1039/C7EE00358G

Kim, D.H.; Park, J., Li, Z.; Yang, M.; Park J.-S.; Park, I.J.; Kim, J.Y.; Berry, J.J; Rumbles, R.; Zhu, K., “300% enhancement of carrier mobility in uniaxial-oriented perovskite films formed by topotactic-oriented attachment,” Adv. Mater., 1606831 (2017).

Park, N.-G.; Grätzel, M.; Miyasaka, T.; Zhu, K.; Emery, K., “Towards stable and commercially available perovskite solar cells,” Nature Energy 1, 16152 (2016).

Zhao, Y.; Zhu, K., “Organic-inorganic hybrid lead halide perovskites for optoelectronic and electronic applications,” Chem. Soc. Rev. 45, 655–689 (2016).

Yang, M.; Zhang, T.Y.; Schulz, P.; Li, Z.; Li, G.; Kim, D.H.; Guo, N.J.; Berry, J.J.; Zhu, K.; Zhao, Y.X., “Facile fabrication of large-grain CH3NH3PbI3-xBrx films for high-efficiency solar cells via CH3NH3Br-selective Ostwald ripening,” Nature Commun. 7, 12305–12305 (2016).

Li, Z.; Yang, M.; Park, J.S.; Wei, S.H.; Berry, J.J.; Zhu, K., “Stabilizing perovskite structures by tuning tolerance factor: Formation of formamidinium and cesium lead iodide solid-state alloys,” Chem. Mater. 28, 284–292 (2016).

Yang, M.; Zhou, Y.; Zeng, Y.; Jiang, C.-S.; Padture, N.P.; Zhu, K., “Square-centimeter solution-processed planar CH3NH3PbI3 perovskite solar cells with efficiency exceeding 15%,” Adv. Mater. 27, 6363–6370 (2015).

Zhang, T.; Yang, M.; Zhao, Y.; Zhu, K., “Controllable sequential deposition of planar CH3NH3PbI3 perovskite films via adjustable volume expansion,” Nano Lett. 15, 3959–3963 (2015).

Zhao, Y.; Zhu, K., “Efficient planar perovskite solar cells based on 1.8 eV band gap CH3NH3PbI2Br nanosheets via thermal decomposition,” J. Am. Chem. Soc. 136, 12241–12244 (2014).