1) Flexible CIGS Solar Cell
We are working on flexible CIGS solar cell in collaboration with KIER from 2016. Polyimide is used as a flexible substrate and solar cell fabrication is based on roll-to-roll process. Our group is mainly focused on electrical and optical characterization of the flexible CIGS solar cell.
Ref: SengYeon Kim et al., Advanced Energy Materials. 14, 1801501 (2018)
2) Kesterite CZTS Solar Cell
Presently, we are interested in low temperature growth of CZTS solar cell. Cation-disorder in kesterite CZTS results in deep defects acting as recombination centers, which are one of main limitation factors to high efficiency cell. We are investigating how to reduce the deep defects in the kesterite solar cell. We are also working on developing Cd-free buffer for the kesterite solar cell. Conduction band alignment between absorber and buffer is main issue in the Cd-free buffer research.
Ref: SeongYeon Kim et al., Nano Energy 45, 75-83 (2018)
3) Material Sciences and Device Physics for Photovoltaics
We have carried out defect characterization of CIGS and CZTS solar cell by using admittance spectroscopy (AS). Power conversion efficiency is strongly correlated with deep defects of the absorber layer. Currently, by using AS, PL and TRPL we are characterizing defect characteristics in more systematic way.
Ref: J.H Heo et al., Advanced Materials 27, 3424 (2015)
4) Perovskite Solar Cells
We are interested in how to increase the lifetime of the perovskite solar cell, which includes 2D/3D hybrid structure, cation-mixing, interface engineering, and defect passivation etc.
5) Next Generation Energy Storage: All-Solid-State Li Ion Battery
We are interested in development of all-solid-state Li ion battery with solid electrolyte such as sulfide and oxide.