ZnS and ZnO Semiconductor Nanoparticles Doped with Mn2+ Ions. Size Effects Investigated by EPR Spectroscopy (original) (raw)

Springer Series in Materials Science, 2014

Abstract

Electron paramagnetic resonance (EPR) spectroscopy has been extensively employed to investigate the presence, localization, distribution and interaction with the host crystalline lattice of the paramagnetic point defects (intrinsic defects and transition metal ions) in semiconductors. The retrieval of such information for nanostructured semiconductors is considerably more difficult, due to the high disorder level in such systems, reflected in broad, featureless EPR spectra. We show here how, with proper adjustments of the EPR experiments and accurate numerical analysis of the resulting spectra, it was possible to obtain more accurate information regarding the localization and structure of various Mn2+ centers in ZnS and ZnO semiconductor nanoparticles (NPs). This lead to the observation and investigation of size related effects such as the presence of the extended lattice defect assisted incorporation of impurities in small (~3 nm) cubic ZnS NPs, the dominant size induced lattice disorder observed for ZnO NPs, independent of the synthesis procedures, or the three steps decomposition of the e-Zn(OH)2 disordered shell of ZnS NPs with formation of new oxy-hydrated zinc compounds. These effects can be used to synthesize semiconductor nanoparticles with controlled size distribution, doping level and functionalized surfaces for specific technological applications.

Mariana Stefan hasn't uploaded this paper.

Let Mariana know you want this paper to be uploaded.

Ask for this paper to be uploaded.