Very thin PbI2 single crystals grown by a hot wall technique

Abstract

A hot wall technique was applied to grow PbI₂ thin films of about 100 nm thickness on cleaved surfaces of CdI₂ single crystals. The band‐edge exciton absorption spectra were investigated for the films grown in various conditions. A very sharp exciton absorption line of 8.8 meV half‐width was obtained in a PbI₂ single‐crystal film grown at a 75 °C substrate temperature. The sharpness of the exciton line proved the excellent quality of the PbI₂ film and the usefulness of the technique.