Controllable deposition of regular lead iodide nanoplatelets and their photoluminescence at room temperature

Highlights: • We synthesized regular single crystalline PbI₂ nanoplatelets based on the physical vapor phase deposition method. • The influences of the substrate location and furnace temperature on the morphologies of PbI₂ nanoplatelets are carried out. • The rules of size, thickness, density of the lead iodide nanoplatelets at varied deposition conditions are analyzed. • We measured the PL spectra of lead iodide nanoplatelets at room temperature. • Pumping power dependent PL measurement indicates two apparent emission peaks are produced by the PbI₂ nanoplatelets. In this work, the synthesis of regular single crystalline lead iodide nanoplatelets are carried out based on the physical vapor phase deposition method. Different lead iodide nanoplatelets are obtained by tuning the location of the mica substrate along with the temperature of the tube furnace. The rules of size, thickness, density of the lead iodide nanoplatelets at varied deposition conditions are analyzed according to the crystal growth principles. It was claimed in literature that the photoluminescence of lead iodide could be obtained only at a low temperature (lower than 200 K). Here, at room temperature, we successfully obtained the photoluminescence spectra of the prepared lead iodide nanoplatelets, which possess two apparent peaks due to the biexcitons and the inelastic scattering of excitons, respectively. Our present study contributes to the development of nanoscaled high performance optoelectronic devices.