Hybrid organic-inorganic perovskites^(*1) have received much attention as potential next generation solar cells and as materials for light-emitting devices.

Kobe University’s Associate Professor TACHIKAWA Takashi (of the Molecular Photoscience Research Center) and Dr. KARIMATA Izuru (previously a graduate student engaged in research at the Graduate School of Science) have succeeded in completely substituting the halide ions of perovskite nanocrystals ^(*2) while maintaining their morphology and light-emitting efficiency.

Furthermore, by using techniques such as single-particle photoluminescence imaging, the researchers were able to understand the momentary changes in light emission and the crystal structure, which in turn enabled them to develop a principle for controlling ion composition.

It is expected that these research results will contribute towards enabling the synthesis of perovskites of varying compositions and advancing the development of devices which utilize them. In addition, it is hoped that the flexibility of perovskite structures can be harnessed, allowing for them to be applied to devices and the creation of new functional materials.

These findings were published in the German academic journal ‘Angewandte Chemie International Edition’ on October 19, 2020.

Research Background

Hybrid organic-inorganic perovskites, such as organic lead halide perovskites (for example, CH₃NH₃PbX₃(X = Cl, Br, I)), have been receiving worldwide attention as a promising material for highly efficient solar cells (Figure 1). Furthermore, the color of the light that they emit can be controlled by altering the type and composition of the halide ions. Consequently, it is hoped that hybrid organic-inorganic perovskites can be applied to light-emitting devices such as displays and lasers.

However, the halide ions inside the crystals are known to move around even at room temperature, and this high flexibility causes issues such as reductions in both synthesis reproducibility and device durability.

Research Method