Fabrication of plasmonic junction diodes based on Ag@ZnO core-shell nanostructures

In this study, Ag nanoparticles and Ag@ZnO core–shell nanostructures were prepared using the wet chemical method and these nanostructures were used for Ag@ZnO/p-Si diode fabrication. Structural, morphological, and optical characterization techniques were applied for Ag@ZnO core–shell NPs prepared by using different molarity of precursor ZnCl 2 (10 mM, 20 mM, 30 mM) and showed that the effect of increasing precursor amount on these physical properties of nanoparticles is important. For Ag@ZnO, transmission electron microscopy shows an average diameter of Ag nanoparticles was 51.32 nm and Ag@ZnO core–shell nanostructures were found to be between 31 and 92 nm. The UV-visible absorbance also shows significant plasmonic resonance for NPs, with a slight red shift increasing precursor molarity. The peaks are found to be from 412 nm to 432 nm. This redshift in surface plasmon absorption of Ag@ZnO core–shell structures are consistent with XPS survey. The current–voltage (I-V) characteristic curves of heterojunction diodes were taken in the dark and at room temperature, and it was observed that they showed a rectifying feature. Ideality factor and barrier height values have been found between 2.14 and 3.87, and 0.56 and 0.78, respectively. The results revealed that Ag@ZnO was successfully synthesized and can be used in rectification applications.