Fig. 3: Chemical binding characterizations of different ligands synthesized CsPbI3 QDs.
From: Stable and efficient CsPbI3 quantum-dot light-emitting diodes with strong quantum confinement
a Fourier transform infrared spectroscopy (FTIR) of oleic acid/oleylamine (OA/OAm) and 2-naphthalenesulfonic acid hexafluorophosphate (NSA-NH4PF6) QDs; for OA/OAm QDs, the peaks at 1750 cm−1 and 1573 cm−1 are attributed to the stretching vibration of C=O and oleate anion (-COO−) of OA, respectively, and the signal peaks at 1642 cm−1 and 908 cm−1 can be attributed to N-H bending vibration and C-N stretching vibration of OAm, respectively34,35. X-ray photoelectron spectroscopy (XPS) of (b) Pb 4 f, (c) I 3d, and (d) N 1 s of OA/OAm QDs and NSA-NH4PF6 QDs.
