| 초록 |
Recently, organometal halide perovskite solar cells (PSCs) have received great attention. The power conversion efficiency (PCE) of PSCs have shown a dramatic increase and certified PCEs in the case of mixed organic cations and halide anions have reached up to 25.2%. The remarkable achievements originate from their specific properties, such as long charge carrier diffusion length, large absorption coefficient and low recombination rate etc. Unfortunately, although photovoltaic characteristics of crystals such as the organometal halide perovskite are strongly concerned with their crystal structure and quality, microstructural analyses of the organometal halide perovskite have not been actively reported. Several analyses such as X-ray diffraction (XRD) have reported important features of the organometal halide perovskite like phase transition or overlap at transition temperature, however, because they cannot offer direct evidence about the configuration of crystal inside, precise and in-depth understanding in microstructure of the organometal halide perovskite is still not sufficient. In this respect, the direct observation of the real microstructural configuration of the organometal halide perovskite via transmission electron microscopy (TEM) has been considered as one of the most needed analysis approaches in PSCs research field. In this talk, I will treat the real microstructural configuration of the organometal halide perovskite showing 1) the phase coexistence and 2) the self-organized superlattices, and 3) the detailed procedure of its thermal degradation on the basis of the TEM investigations. The newly identified characteristics of the organometal halide perovskite will shed light on its potential as promising materials for next-generation renewable energy devices. |
