Speaker
Description
APbBr3 (A = FA, Cs) perovskites have emerged as benchmark materials for X-ray and gamma-ray detection, combining excellent X-ray stopping power with high processability. While FAPbBr3 is typically processed in solution, the congruent melting nature of CsPbBr3 allows synthesis from melted precursors or via vacuum deposition techniques. However, scalable fabrication that meets device performance requirements remains challenging.
Close space sublimation (CSS) represents an attractive, industry-relevant deposition technique due to its high growth rates, solvent-free process, and compatibility with large-area manufacturing. Nevertheless, the single-source nature of CSS and the close proximity between the material source and substrate require careful control over deposition conditions.
This work demonstrates the growth of CsPbBr3 films using CSS, exploring the flexibility of process parameters to tune film properties. Key findings establish CSS as an effective technique for depositing high-quality polycrystalline CsPbBr3 films with thicknesses ranging from nanometers to hundreds of micrometers. Remarkable growth rates from 1 to 15 μm/min, along with the ability to tailor film morphology and deposited surface area using shadow-masking, highlight the advantages of CSS for perovskite absorber deposition. The fabrication of fully functional 4 × 4 cm² imagers on TFT pixelated backplanes is demonstrated, establishing CSS as a promising technique for dynamic X-ray imaging applications. First demonstrators of large-area 20 × 20 cm² X-ray imagers are presented, paving the way for advanced X-ray radiography. Finally, the potential of CSS for growing more complex perovskite compositions, including hybrid structures such as FAPbBr3, is discussed.