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 ZnCl2 (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.