Optimization of halide perovskite nanocrystals for advanced optoelectronics

This PhD thesis presents a comprehensive study of perovskite light-emitting diodes (PeLEDs), addressing key challenges that limit their commercialization. The first study evaluates the impact of purification on the optical properties of CsPbBr₃ nanocrystals, comparing different post-synthetic protocols. An absorbance-based method is also developed to assess material quality between batches, enabling the fabrication of efficient and reproducible PeLEDs. The second part investigates the colloidal stability of perovskite nanocrystals in polar media through a systematic study of alkylammonium bromide ligands (DDAB, BDAB, TBAB), revealing how ligand structure and steric effects influence surface passivation and defect suppression. Finally, the device architecture is optimized by replacing the conventional PEDOT:PSS layer with self-assembled monolayers (SAMs), improving band alignment, luminance, EQE, and reproducibility while reducing cost. Overall, this thesis advances understanding of material purification, surface chemistry, and interface engineering toward efficient, stable, and scalable perovskite-based LEDs.