Fig. 3: Transformation of Zn and Se adatoms to crystalline ZnSe epitaxial layer.
a Raman spectra of InP–OA NCs with a size of 3.3 nm (grey) and InP–ZnSe NCs annealed at elevated temperatures of 200 (deep blue), 240 (blue), 280 (light blue), and 340 °C (cyan). InP–ZnSe prepared in the presence of HF (purple dotted line) resulted in a stronger ZnSe LO mode. b X-ray diffractograms of InP–OA (grey), InP–ZnSe (blue), and InP/ZnSe (light blue; annealed at 340 °C). For comparison, diffraction lines of bulk InP (black) and ZnSe (blue) are included at the bottom. c Intensities of In(P)Ox (open square) and ZnSe LO phonon modes (solid circle) at different reaction temperatures without (light blue) and with HF (purple). Grey background represents the noise level. d Hydrostatic strain (Δα/α) applied to InP NCs with a size of 3.3 nm by a single ZnSe epitaxial layer generated at different annealing temperatures with (purple solid diamond) and without HF (light blue open square). The dashed line represents theoretical compressive strain by double ZnSe epitaxial layers based on the elastic continuum theory. e Raman spectra of InP–OA at ~150 cm–1 with sequential treatments: HF addition at 120 °C (purple), and Zn(OA)2 addition at 120 °C (light blue) and at 280 °C (green). Dotted grey line indicates pristine InP–OA. All Raman spectra were normalised to the InP LO peak. The surface migration of oleate and the proposed oxidation pathway are illustrated on the right. All samples are characterised using InP–OA NCs with a size of 3.3 nm. Source data are provided as a Source Data file.
