X-Ray Photoelectron Spectroscopy and Raman Scattering Studies of ALD Alumina Coated ZnTe Nanowires

Wednesday, 27 May 2015
Salon C (Hilton Chicago)
K. Pradhan, S. Sahoo (University of Puerto Rico), J. H. Peng, H. Yu, S. K. Dey (Arizona State University), and R. S. Katiyar (University of Puerto Rico)
Semiconductor nanowires (NWs) represent a versatile platform for evaluating novel phenomena at the nanoscale and also exhibit high potential for applications in future electronic, photovoltaic, and optoelectronic devices [1]. Moreover, the fabrication of core-shell heterostructures based on semiconductor NW-insulator heterostructures further enable the generation of devices with diverse functions. In this work, the fabrication of core-shell heterostructures, via metal-catalyzed vapor–liquid–solid synthesis of Zinc Telluride (ZnTe) NWs followed by the conformal coating of alumina (Al2O3) by atomic layer deposition (ALD), has been demonstrated.  While the former is a direct band gap (~ 2.26 eV), II-VI semiconductor in the blue-green region of the spectrum, the latter is a high band gap (~ 6.4 eV) insulator that is amorphous. Here, preliminary x-ray photo electron spectroscopy (XPS) and Raman scattering results on the ZnTe/Al2O3 core-shell nanostructures are presented and discussed. Additionally, photoluminescence spectra of coated and uncoated ZnTe NWs are discussed in light of the variations in peak position and line-width.


1. J. Wallentin, et al, InP nanowire array solar cells achieving 13.8 % efficiency by exceeding the ray optics limit, Science 339, pp. 1057-1060, (2013).