Structural and electronic investigation of metal-semiconductor hybrid tetrapod hetero-structures

This article highlights the new electronic properties of tetrapod hetero-structures with metal Au core and semiconductor CdSe arms, which is one of the new classes of hybrid metal-semiconductor nanostructures. From the analysis of XRD, HRTEM, HAADF-STEM images, and EDAX line-scan studies, the growth mechanism of all these hetero-structures is proposed. These findings are important from the basic fundamental aspects of understanding the shape control of hetero-structures. Scanning tunneling spectroscopic study confirms the coulomb staircase-like features near Au which is characteristic of Au nanoparticles and the gap increases as we move the tip towards CdSe. Analysis suggests that the resonance tunneling occurs between valance band edge (conduction band edge) of CdSe and coulomb stairs of Au dot. These tetrapod hetero-structures could pave the way for designing new optical-based materials for developing new challenging photonic devices.