Structural and photo luminescent properties of uncapped nanocrystalline Cd1-xZnxS solid solutions

Uncapped nanocrystalline Cd1-xZnxS (0.0 <= x >= 0.5) solid solution prepared by microwave assisted combustion route shows hexagonal to cubic phase transformation for even low doping of zinc up to 5 at.% as evident from the X-ray diffraction patterns and the selected area electron diffraction patterns. The solid solutions show a considerable shift in the optical absorption edge from similar to 2.43eV (CdS) to similar to 2.73 eV for the equi-atomic composition (Cd0.5Zn0.5S). The blue emission in CdS shows effect of quantum confinement. The photo luminescence spectra of Zn lean compositions (up to 5 at.%) show emergence of a peak at lambda similar to 530 nm along with the blue emission features of US. However, solid solutions with higher zinc content (tip to 50 at.%), show a systematic increase in the intensity of peak at 530 rim with a blue shift up to 30 at.% of zinc doping. Beyond 30%, a broad blue-green emission with full width at half maxima of similar to 100 nm for Cd0.5Zn0.5S is observed. (C) 2008 Elsevier B.V. All rights reserved.