Optical Properties of Carbon Doped Metal Telluride Core-Shell Structures for Optoelectronic Applications

Abstract

Modern lighting technologies (LEDs and display devices) based on semiconductor Quantum dot (QD) luminescent materials employ semiconductor metal chalcogenides including ZnS, ZnSe, PbS, PbSe, CdS and CdSe. However, they suffer with non-radiative recombination due to surface and structural defects and most of the metal chalcogenides including Cd and Pb are toxic in nature. Moreover, zinc-based chalcogenides including ZnS and ZnSe are also investigated as luminescent materials but sulfides and selenides are toxic in nature. Therefore, there is a large space available to explore non-toxic novel materials and to investigate their luminescent properties based on also exhibit toxicity and their luminescent properties are tuned using complex architectures such as ZnSxSe(1- x) and CdSxSe(1-x). Whereas, Zinc telluride is a chalcogenide having optimum band gap of 2.25eV is less toxic and its optical properties are easily tunable due to optimum bandgap. Moreover, carbon-based materials (carbon derivatives, QDs) offer a huge variety of tunable energy states with non-toxic nature of the materials. and their photoluminescent properties investigated suitable for lighting devices including LEDs, display devices and photo-sensors. In this work, ZnTe/carbon allotropes (graphene derivatives/QDs) based nanocomposite/core-shell nanostructures synthesized by wet-chemical method. The structural, morphological, and optical properties of the prepared samples are studied using XRD, Raman spectroscopy, UV-Visible and PL spectroscopy techniques.