Nanomaterials - 16

Abstract

Perovskite semiconductors are expected to be applied to high-efficiency solar cells and light-emitting devices because of their strong optical absorption in a wide range of visible light and strong emissions at room temperature. Among perovskite semiconductors, double perovskite semiconductors are materials that contain monovalent metal cations and trivalent metal cations. Especially, Cs₂AgInCl₆ belongs to space group \( Fm ̅3m \) at room temperature with AgCl₆ and InCl₆ octahedra connected to each other at the corners. This semiconductor has a direct band gap and is known to exhibit white luminescence associated with self-trapped excitons (STEs) derived from strong electron-lattice interactions. From the characteristics, it is expected to be applied to white LEDs [1]. In this study, the effects of pressure-induced perturbations on the electronic state and structural change of Cs₂AgInCl₆ have been clarified by XRD measurements and optical measurements under high pressure. It is very important to understand the relationship between a structural change such as octahedral distortion and a change in electronic states. The high pressure can effectively change crystal lattice and electronic states, as shown in Figs. 1 and 2.