Facet-specific ligand dynamics: scaling the descriptors of Cs₂AgBiBr₆ nanocrystals

Facet control by primary amines can bolster the optoelectronic parameters of A(2)B(I)B ' X-III(6) perovskite nanocrystals (NCs) with large indirect bandgaps. The 18-C amine competitively attaches to the (222) facet of Cs2AgBiBr6 (CABB) NCs, 16-C and 14-C bind to (400) and (440), and 12-C binds to (400). The NCs with only the (400) facet decrease the bandgap and exciton binding energy by 0.26 eV and 15 meV, respectively.