Quantifying Wavelength-Dependent Plasmonic Hot Carrier Energy Distributions at Metal/Semiconductor Interfaces.

Hot carriers generated from the nonradiative decay of localized surface plasmons are capable of driving charge-transfer reactions at the surfaces of metal nanostructures. Photocatalytic devices utilizing plasmonic hot carriers are often based on metal nanoparticle/semiconductor heterostructures owing to their efficient electron-hole separation ability. The rapid thermalization of hot carriers generated at the metal nanoparticles yields a distribution of carrier energies that determines the capability of the photocatalytic device to drive redox reactions.

Strain-Engineered Oxygen Vacancies in CaMnO Thin Films.

We demonstrate a novel pathway to control and stabilize oxygen vacancies in complex transition-metal oxide thin films. Using atomic layer-by-layer pulsed laser deposition (PLD) from two separate targets, we synthesize high-quality single-crystalline CaMnO films with systematically varying oxygen vacancy defect formation energies as controlled by coherent tensile strain. The systematic increase of the oxygen vacancy content in CaMnO as a function of applied in-plane strain is observed and confirmed experimentally using high-resolution soft X-ray absorption spectroscopy (XAS) in conjunction with bulk-sensitive hard X-ray photoemission spectroscopy (HAXPES).