[(4AMTP)PbBr2]2PbBr4: a Nontypical Cation-Coordinated Perovskite Showing Deep-Blue Emissions and Blue-Light Photoelectric Response br

Metal-halide perovskites have been extensively investigated due to their fascinating structural diversity and outstanding optoelectronic properties. We report the photo-luminescence and photoelectric response behavior of a nontypical Dion-Jacobson perovskite [(4AMTP)PbBr2]2PbBr4 (4AMTP = 4-aminomethyltetrahydropyran cation), featuring neutral PbBr2 layers incorporated into the cationic layers between the anionic [PbBr4]2- layers. A 4AMTP-coordinated PbBr2 unit constitutes the unique nontypical dication layer. The seven-coordinated PbBr6O unit forms a largely distorted decahedron with a short distance from the inorganic [PbBr4]2- layer. The photoluminescence behavior of [(4AMTP)PbBr2]2PbBr4 shows crystal size dependence. Larger crystals show purplish-blue emission with two peaks at 414 and 431 nm, whereas smaller grain size (<50 mu m) crystals demonstrate a single emission peak at 425 nm. Meanwhile, it shows a blue-light photoelectric response under the illumination of 405 nm with an on/off ratio of 175 for single-crystal devices and 97 for thin-film devices. The photoresponse performance is proportional to the molar extinction coefficient of the absorption band edge.

Automated summary

Metal-halide perovskites, such as [(4AMTP)PbBr2]2PbBr4, have diverse structures and excellent optoelectronic properties. This study investigates their photoluminescence and photoelectric response behavior. The emission color can be tuned by changing the crystal size, and the material exhibits blue-light photoelectric response at a specific wavelength, proportional to the molar extinction coefficient of the absorption band edge.