Plasmon-Enhanced Surface Photovoltage of ZnO/Ag Nanogratings

Abstract

We investigated the surface photovoltage (SPV) behaviors of ZnO/Ag one-dimensional (1D) nanogratings using Kelvin probe force microscopy (KPFM). The grating structure could couple surface plasmon polaritons (SPPs) with photons, giving rise to strong light confinement at the ZnO/Ag interface. The larger field produced more photo-excited carriers and increased the SPV. SPP excitation influenced the spatial distribution of the photo-excited carriers and their recombination processes. As a result, the SPV relaxation time clearly depended on the wavelength and polarization of the incident light. All of these results suggested that SPV measurement using KPFM should be very useful for studying the plasmonic effects in nanoscale metal/semiconductor hybrid structures.

Chemistry and Charge Trapping at the Interface of Silver and Ultrathin Layers of Zinc Oxide

“…The diagram resembles the Schottky junction of an n-type semiconductor in contact with a metal of a larger work function, as compared to that of the semiconductor. 27 However, the decrease in CPD during supra-band-gap illumination is contrary to the expectation from the built-in electric field ( Figure 8 ). The latter would suggest photo-induced electron accumulation at the ZnO surface, whereas the actual result corresponds to hole accumulation.…”

“… 34 In another study, SPPs increased the charge separation efficiency and surface photovoltage (SPV) in Ag/ZnO gratings. 27 Alternatively, SPR increases the electron density at the ZnO defect states and enhances visible-light emission. 22 Brillson and co-workers, 35 , 36 and Durbin and co-workers, 37 have studied and emphasized the electronic implications of defect states at metal/ZnO interfaces.…”

Photothermal Plasmonic Actuation of Micromechanical Cantilever Beams

“…However, the mechanical response of coated mechanical resonators, such as cantilever beams, when driven by optical excitation at various wavelengths across the visible spectral domain remains unexplored. This is critical for experiments conducted with tunable light sources, as needed for instance in microscopic photovoltage spectroscopy [42,43], Kelvin probe force microscopy under illumination [44,45], photo-piezoresponse and photoelectric force microcopy [46][47][48], or photoinduced force microscopy and spectroscopy [49][50][51][52].…”

Mie Resonance-Modulated Spatial Distributions of Photogenerated Carriers in Poly(3-hexylthiophene-2,5-diyl)/Silicon Nanopillars

“…Thus, the generation of electron-hole pairs and their separation directly determine surface photovoltage (SPV), defined as the difference of V surf in the dark and under light. Kelvin probe force microscopy (KPFM) enables real space mapping of V surf with nanoscopic spatial resolution 24 25 26 .…”

“…V surf of the samples in the dark and under illumination by a red laser (wavelength λ = 635 nm) was measured using a KPFM system (XE-100, Park Systems) inside a glove box 24 25 . The glove box was purged with N 2 gas for at least 3 h after loading each sample and the N 2 atmosphere was maintained throughout the experimental procedures.…”