Resolving hot-carrier photocurrent pathways in operating Schottky nanodiodes by time-resolved two-pulse photocurrent spectroscopy
Year: 2026
Type: article
Abstract: Determining how nonequilibrium carriers contribute to photocurrent in a functioning Schottky junction remains challenging because ultrafast relaxation and interfacial transmission pathways are typically inferred rather than quantitatively separated under device-operating conditions. Here, we present time-resolved two-pulse photocurrent spectroscopy (TR-2PPS), an all-electrical readout time-domain method that turns the Schottky barrier into an intrinsic energy filter and partitions the photocurrent into pathway-resolved components. Fitting time-delay-dependent photocurrent traces separates a prompt, delay-independent baseline (I base ) from a delay-dependent nonlinear component (I exp ) with a sub-picosecond lifetime ( τ decay ), directly tracking the survival of the current-generating electron population. The bias dependence of A exp and τ decay allows us to distinguish a collection-enhancement regime from a high-reverse-bias regime in Au/TiO 2 where both the delayed pathway weight and its apparent lifetime increase. Across Au, Ag, Pt, and Pd/TiO 2 , TR-2PPS yields metal-dependent lifetimes and electron-phonon coupling constants (G ep ) consistent with ultrafast diffraction benchmarks using a single excitation wavelength.
Source: Matter & Light
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G3148917236, G3916497809, G4846768360
OpenAlex ID: W7164418637