Tunable Localized Surface Plasmon Resonance and Broadband Visible Photoresponse of Cu Nanoparticles/ZnO Surfaces

Abstract

Plasmonic Cu nanoparticles (NP) were successfully deposited on ZnO substrates by atomic layer deposition (ALD) owing to the Volmer-Weber island growth mode. An evolution from Cu NP to continuous Cu films was observed with increasing the number of ALD cycles. Real and imaginary parts of the NP dielectric functions, determined by spectroscopic ellipsometry using an effective medium approach, evidence a localized surface plasmon resonance that can be tuned between the visible and near infrared ranges by controlling the interparticle spacing and size of the NP. The resulting Cu NP/ ZnO device shows an enhanced photo-response under white light illumination with good responsivity values, fast response times and stability under dark/light cycles. The significant photocurrent detected for this device is related with the hot electron generation at the NP surface and injection into the conduction band of the ZnO. The possibility of tuning the plasmon resonance together with the photo-responsivity of the device is promising in many applications related with photo-detection, photonics and photovoltaics.

Self‐Polarized BaTiO3 for Greatly Enhanced Performance of ZnO UV Photodetector by Regulating the Distribution of Electron Concentration

“…However, the practical applications of ZnO film UV PDs have been seriously hindered from their low on/off ratio (≈10) or long decay time (≈20 s) due to the influence of adsorption and desorption of surface oxygen molecules . A variety of methods have been reported for improving the performance of ZnO devices including surface plasma modification, internal doping, heterojunction, and surface functionalization . Ouyang et al integrated ZnO film UV PDs with CdMoO 4 microplates.…”

Surface Plasmonic‐Assisted Photocatalysis and Optoelectronic Devices with Noble Metal Nanocrystals: Design, Synthesis, and Applications

“…a) Schematic diagram and results of ZnO‐based photodetector. Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…De Melo et al fabricated photodetector on ZnO substrate via atomic layer deposition owing to the Volmer-Weber island growth mode. [128] After that they grew the CuNPs onto the ZnO-based substrate and achieved the phenomena within the premises of Volmer-Weber island that was in the growth mode at a very early stage of deposition. Due to the outstanding properties of the NPs, they investigated that LSPR of Cu NPs can be tunable between the visible and NIR spectrum.…”

“…Reproduced with permission. [128] Copyright 2018, American Chemical Society. b) Schematic diagram of CQD-based double band detector.…”

Ultrahigh Responsivity UV Photodetector Based on Cu Nanostructure/ZnO QD Hybrid Architectures

“…To match the response spectra of photodetectors, it becomes crucial to choose an appropriate metal for supporting a strong localized surface plasmon resonance (LSPR), which can cover the wavelength above the bandgap energy of ZnO. Compared with the traditional noble metals (Ag and Au), Cu exhibits an excellent LSPR within a relatively broader wavelength range below 600 nm, and it guarantees a strong absorbance of ZnO with the enhanced surface scattering . Moreover, Cu is also low cost and malleable, which is suitable for fabrication of nanostructures with tunable configuration to manipulate the light–mater interaction.…”