Capping Ligand Influence on the Structural, Optical and Luminescence Properties of CdTe Nanoparticles Prepared by a Simple Wet Chemical Process

Abstract

The nature of the capping ligands used and the strength of their interactions with the surface atoms of the nanoparticles (NPs) impact greatly on the material properties and the stability of the resulting NPs. The structural analysis revealed that all the as‐prepared CdTe NPs samples had a zinc blende crystal structure of different phases. The glutathione and L‐cysteine capped CdTe NPs had the same zinc blende phase (JCPDS no. 75–2086) while thioglycolic acid capped and co‐capped CdTe NPs possessed another zinc blende phase (JCPDS no. 75–2083). The calculated crystallite sizes were in the range 2–26 nm for all the samples. The optical spectroscopy studies showed various properties when different capping ligands were used. The band gap energies for all the as‐prepared CdTe NPs confirmed the results obtained from the X‐ray diffraction. The band gap energies were in the range of 2.39–3.34 eV for all the as‐prepared CdTe NPs.