Synthesis of large two-dimensional lead-free bismuth–silver double perovskite microplatelets and their application for field-effect transistors

Two-dimensional phenylethylammonium (PEA, C8H9NH3) Bi-Ag double perovskite (PEA)4BiAgX8 (X = Br, I) microplatelets are synthesized for the first time via a facile self-assembly recrystallization method. Absorption spectra of microplatelets exhibit direct bandgaps and different halide compositions show distinct morphologies and bandgap tunability. Field-effect transistors based on a single (PEA)4BiAgBr8 microplatelet display a p-type semiconducting behavior.