Effects of gold nanoparticles on the growth of ZnO thin films and p-Si/ZnO heterostructures

Gold nanoparticles (AuNPs) were grown on p-Si substrate in order to investigate its effects on the optical, electrical and structural characteristics of the electrochemically deposited ZnO thin films and produced p-Si/AuNP/n-ZnO hetero-structures. Homogenous distribution of AuNPs on p-Si substrate with an average size of 150 nm and surface plasmon resonance wavelength around 700 nm has been observed. Polycrystalline nature of ZnO thin films have been confirmed with the dominant crystal plane of (002) for the sample grown on bare p-Si substrate, while it is (100) plane dominant for the sample grown on the AuNPs/p-Si substrate. Formation of Zn-rich ZnO has been realized in ZnO thin films grown on the AuNPs substrate, while it is O-rich in the thin films grown on p-Si substrate with X-ray Photoelectron Spectroscopy. Enhancement of Raman peaks, near-bandedge and intra-bandgap absorption, and the near-bandedge emission has been observed on the ZnO thin films grown on AuNPs. Higher forward bias current values have been observed in the hetero-structure produced by interface AuNPs, p-Si/ AuNPs/n-ZnO.