General hot-plate heating is used to form a crystal structure of films; however, how to achieve a homogeneous and regulated crystal formation will be a crucial challenge in the future. In this study, based on perovskite-series materials, organic methylamine lead trioxide (MAPbI3) films doped with inorganic lead iodide (CsPbI3) quantum dots (QDs) are treated using the rapid thermal annealing (RTA) process in argon gas to break the crystallization barrier. These RTA-treated perovskite quantum dot (PQD) films at various temperatures of 100–160 °C are detected using X-ray diffraction, X-ray spectroscopy, and absorbance measurements to investigate their structural and optical properties as well as their binding states. The experimental results demonstrate that the PQD film annealed at 120 °C has optimized characteristics, revealing better crystallinity and the lowest content of oxygen atoms (31.4%) and C-O-C bonding (20.1%). A too-high RTA temperature, more than 140 °C, causes severe degradation with the existence of PbI2. A proper RTA process, an alternative to normal heating and annealing, can effectively inhibit the occurrence of degradation and even usefully improve the performance of PQD films.

After the preparation of inorganic perovskite cesium lead iodide quantum dots (CsPbI3 QD) by ligand-assisted reprecipitation (LARP), CsPbI3 QD was added to the organic perovskite methylamine lead triiodide (CH3NH3PbI3; MAPbI3) to successfully form composite perovskite film. To obtain better perovskite quantum dot (PQD) crystal characteristics, this research used different annealing temperatures to discuss the crystallinity changes of perovskite quantum dots (PQD). Through X-ray diffraction (XRD) analysis, it was found that the preferred peak (110) of MAPbI3 had maximum peak intensity when the annealing temperature increased to 120 °C. Based on the measurement results of PQD’s Ultraviolet-Visible spectrum, it was shown that the maximum absorption area was obtained at the wavelength of 350 nm~750 nm at the annealing temperature 120 °C. From the scanning electron microscope (SEM) measurement, it was found that the grain size was the largest at the annealing temperature 120 °C, and the grain size was 60.2 nm. The best crystallization characteristics of PQD were obtained at the annealing temperature 120 °C.