Fig. 3: Energy-independent interfacial electron transfer.
From: Interface-driven energy-independent charge extraction in GaN photocatalysts
a Atomic force microscopy (AFM) image of GaN after surface Pt modification. b Height profile along the dashed white line in a, showing Pt nanoislands with an average height of approximately 0.65 nm. c High-resolution Pt 4 f X-ray photoelectron spectroscopy (XPS) of GaN and Pt/GaN samples. d Representative two-dimensional pseudo-color 2PPE spectrum of Pt/GaN acquired under one-color excitation at a photon energy of 4.49 eV (276 nm) after background subtraction using the signal recorded at –5 ps. e 2PPE spectra of Pt/GaN recorded at various pump-probe delay times. The inset displays an enlarged view within the energy range of 1.0–3.8 eV. f Temporal evolution of the normalized photoemission intensity for excited-state carriers at selected energies. The shaded red curve represents the autocorrelation trace of the pump and probe pulses. g Extracted time constants as a function of excited-state energy, revealing an energy-independent interfacial electron transfer process. Error bars represent the standard deviation of the fits.
