Self‐Organized Superlattice and Phase Coexistence inside Thin Film Organometal Halide Perovskite

• DOI: 10.1002/adma.201705230
• Publication Date: 2018-01-10T15:18:48Z
• Authors: Tae Woong Kim; Satoshi Uchida; Tomonori Matsushita; Ludmila Cojocaru; Ryota Jono; Kohei Kimura; Daiki Matsubara; Manabu Shirai; Katsuji Ito; Hiroaki Matsumoto; Takashi Kondo; Hiroshi Segawa
• Keywords: Tetragonal crystal system

Organometal halide perovskites have attracted widespread attention as the most favorable prospective material for photovoltaic technology because of their high photoinduced charge separation and carrier transport performance. However, microstructural aspects within organometal perovskite are still unknown, even though it belongs to a crystal system. Here direct observation microstructure thin film using transmission electron microscopy is reported. Unlike previous reports claiming each phase solely exists at given temperature range, identified that tetragonal cubic phases coexist room temperature, confirmed superlattices composed mixture self-organized without compositional change. The self-adjusts configuration automatically organizes buffer layer boundaries by introducing superlattice. This report shows fundamental crystallographic information demonstrates new possibilities promising materials various applications.