Systematic Approach to the Study of Optical Stability According to the Crystal Structure of Perovskite Quantum Dots

In our study, we investigated the crystal structure and optical properties of multiphase CsPbBr3 quantum dots (QDs). CsPbBr3 QDs can exist in three different crystal structures, but distinguishing them using X-ray diffraction (XRD) is challenging due to their high similarity. Therefore, we utilized XRD and Lasso-regression analysis to successfully differentiate between the cubic and orthorhombic phases of CsPbBr3 QDs. Additionally, we examined the photoluminescence properties of the QDs, including their emission spectra, quantum yield, and stability over time. Our results revealed that the cubic phase exhibited higher photoluminescence quantum yield and better stability compared to those of the orthorhombic phase, indicating that the crystal structure significantly affects the optical properties of the QDs.