• Electron-phonon coupling strength in CsPbBr3 QDs in solution is twice that in thin films, indicating ligand phonon involvement in solution.
• PL lifetime in solution (22.5 ns) is longer than in film (5 ns) at room temperature, with both decreasing abnormally at lower temperatures due to thermally activated trap states.
• Trap energy levels are deeper in thin films (~20 meV) compared to solution (~4 meV), affecting non-radiative recombination.
• The morphology of organic ligands regulates electron-phonon interactions and optoelectronic properties in CsPbBr3 QDs.