Synthesis of cesium silver bismuth bromide double perovskite nanoparticles via a microwave-assisted solvothermal method

Bismuth-based perovskites have been widely investigated in recent years as an alternative candidate for resolving the toxicity of a high-performance lead-based perovskite. In this work, we present the synthesis of a cesium silver bismuth bromide (Cs2AgBiBr6) perovskite employing a microwave-assisted solvothermal method, which offers features for simple and minute-scale sample synthesis. The X-ray diffraction and Raman spectroscopy results reflected the high purity of bismuth-based perovskites synthesized at non-inert conditions. Field-emission scanning electron microscopy and energy-dispersive X-ray showed a particle size of 72 nm and Br-rich or Cs-deficient condition in the materials, respectively. The synthesized material also shows promising moisture and thermal stability. Ultraviolet–visible spectroscopy and temperature-dependent photoluminescence spectroscopy revealed the electronic structure and nature of the material, including low carrier localization and a strong electron-phonon effect. The time-resolved photoluminescence revealed a carrier lifetime of 921 ns, which is desired for an optoelectronic application. These findings point to a simple and rapid method for producing Cs2AgBiBr6 perovskite nanoparticles.