Plasmon-enhanced lateral photovoltaic effect observed in Ag-ZnO core–shell nanoparticles

Abstract

The lateral photovoltaic effect (LPE) is widely used in sensitive position detectors. Discovering comprehensive mechanisms and continuously improving their sensitivity are the ongoing goals in this field. However, the limited absorption and rapid recombination are two major challenges in the traditional LPE. Here, surface plasmon-based approaches have been used to boost the energy conversion efficiency, and the Ag-ZnO core–shell nanoparticles (NPs) with enhanced LPE are prepared on the Si substrate through atomic layer deposition. Owing to the enhanced light absorption, prolonged hot electron generation, and plasmon-induced charge separation, this system exhibits good LPE performance with a maximum sensitivity of 122.1 mV/mm at 980 nm, which is about seven times larger than that observed in conventional Ag/Si (5.03 mV/mm) and ZnO/Si (76.13 mV/mm). Besides, its sensitivity can increase up to 114.7% by using rapid thermal annealing to change the shape and size of active plasmon Ag NPs. Furthermore, the surface-enhanced Raman scattering spectra and finite-difference time-domain electric field simulation prove the occurrence of localized surfaced plasmon resonance excitation. This infrared sensitive shell-isolated structure has great potential for applications in high sensitivity and stability photoelectric devices.