A comprehensive comparative investigation of thick layer and microcrystalline CsPbBr3 perovskite material: optical and electrical properties

Lately, researchers have been investigating perovskite materials as they have attracted an enormous amount of attention due to their interesting properties. In this paper we are emphasizing the preparation method to obtain microcrystals or thick layers of CsPbBr 3 perovskite materials. Prepared samples, on an ITO substrate, are characterized optically by the means of the stationary photoluminescence (PL) and the Time-Resolved photoluminescence (TRPL). Electrically, they are characterized by the meaning of I – V technique. The PL spectra of the microcrystal’s samples (denoted S1) show the presence of two peaks. The peak associated with the highest energy level allowed the determination of the bandgap energy ( E g ), yielding a value of 2.37 eV. On the other hand, the thick layer samples (denoted S2) revealed a single sharp peak with a band gap energy E g = 2.33 eV. The TRPL of S1 has shown a carriers’ lifetime τ = 37.2 ns. However, the S2 manifested a faster decay with a carriers’ lifetime τ = 0.88 ns. By studying the I–V responses, we have revealed that the Schottky contacts are sensitive to light, and they show a normal hysteresis (NH) and inverted one (IH) depending on the type of the sample. In both sample types, the manifestation of a self-heating phenomenon has been observed. Notably, this observation represents a novel contribution to the existing literature, as, to the best of the authors’ knowledge, such a phenomenon has not been previously reported in the study of CsPbBr3.