Hybrid nanostructures have a great potential to improve the overall properties of photonic devices. In the present study, silver nanoparticles (AgNPs) were infiltrated into nanostructured porous silicon (PSi) layers, aiming at enhancing the optoelectronic performance of Si-based devices. More specifically, Schottky diodes with three different configurations were fabricated, using Al/Si/Au as the basic structure. This structure was modified by adding PSi and PSi + AgNPs layers. Their characteristic electrical parameters were accurately determined by fitting the current-voltage curves to the non-ideal diode equation. Furthermore, electrochemical impedance spectroscopy was used to determine the electrical parameters of the diodes in a wide frequency range by fitting the Nyquist plots to the appropriate equivalent circuit model. The experimental results show a remarkable enhancement in electrical conduction after the incorporation of metallic nanoparticles. Moreover, the spectral photoresponse was examined for various devices. An approximately 10-fold increment in photoresponse was observed after the addition of Ag nanoparticles to the porous structures.
Keywords: impedance spectroscopy; photoresponse; porous silicon; reflectance; silver nanoparticles.