Presentation Information
[19p-P04-23]Development of High Efficiency Organometal Halide Perovskite Solar Cells via Phase Control of Light Absorber
〇Taewoong Kim1, Satoshi Uchida2, Sang Geun Cho1, So Jeong Kim1, Takashi Kondo2, Hiroshi Segawa2 (1.Konkuk Univ., 2.Univ. of Tokyo)
Keywords:
perovskite solarcell,transmission electron microscopy,phase control
Organometal halide perovskite (OHP) has received great attention as the next-generation photovoltaic materials based on the unprecedented achievements in solar cell application, since the first organometal halide perovskite solar cell (PSC) using methylammonium lead iodide (MAPbI3, MA = CH3NH3) was reported. Recently, the certified power conversion efficiency (PCE) of the PSCs have reached up to 26% exceeding top records of some conventional solar cells.
Controlling the grain size of the OHP to reduce grain boundaries in the OHP light absorber is one of the well-known techniques for the development of high efficiency PSCs because the grain boundaries act as defects and, thus, induce negative influences on the performance of the PSCs. Until now, plenty of research concerning grain of the OHP and its boundaries have been executed for the high efficiency PSCs however there is enough possibility for further enhancement. For this reason, various attempts for the improvements of the boundary and the interface condition of the OHP are still actively being conducted.
In this study, we identified that large physical gaps exist at the grain boundary of the OHP (MAPbI3) with transmission electron microscopy (TEM) analysis and revealed that the physical gap blocks charge carrier flow in the MAPbI3 light absorber. To minimize the physical gap and its negative influences, the grain size of the MAPbI3 perovskite was enlarged by increasing ratio of the cubic phase via microstructural phase control using liquid nitrogen (LN2). As the result of the adopting the microstructural phase control, the grain boundaries and physical gap of the MAPbI3 light absorber were significantly decreased and, finally, 20.23% PCE was achieved with a single cation MAPbI3 PSC.
Controlling the grain size of the OHP to reduce grain boundaries in the OHP light absorber is one of the well-known techniques for the development of high efficiency PSCs because the grain boundaries act as defects and, thus, induce negative influences on the performance of the PSCs. Until now, plenty of research concerning grain of the OHP and its boundaries have been executed for the high efficiency PSCs however there is enough possibility for further enhancement. For this reason, various attempts for the improvements of the boundary and the interface condition of the OHP are still actively being conducted.
In this study, we identified that large physical gaps exist at the grain boundary of the OHP (MAPbI3) with transmission electron microscopy (TEM) analysis and revealed that the physical gap blocks charge carrier flow in the MAPbI3 light absorber. To minimize the physical gap and its negative influences, the grain size of the MAPbI3 perovskite was enlarged by increasing ratio of the cubic phase via microstructural phase control using liquid nitrogen (LN2). As the result of the adopting the microstructural phase control, the grain boundaries and physical gap of the MAPbI3 light absorber were significantly decreased and, finally, 20.23% PCE was achieved with a single cation MAPbI3 PSC.