Low-cost fabrication of ternary CuInSe2 nanocrystals by colloidal route using a novel combination of volatile and non-volatile capping agents

• Wet-route synthesis of CISe nanocrystals reported without post-selenization process.
• Single-phase, stable and well-passivated colloidal ternary CISe nanocrystals formed.
• Novel combination of capping agents: volatile aniline and non-volatile 1-octadecene.
• Higher growth temperature attained using the colligative properties of the mixture.
• Metallic salts presence explains exp. and theoretical boiling point difference.

Wet-route synthesis of CuInSe2 (CISe) nanocrystals has been envisaged with the utilization of the unique combination of coordinating ligand and non coordinating solvent. Our work demonstrates the formation of a single-phase, nearly stoichiometric and monodispersive, stable and well-passivated colloidal ternary CISe nanocrystals (band gap (Eg)~1.16 eV) using a novel combination of ligands; viz. volatile arylamine aniline and non-volatile solvent 1-octadecene. The synthesis and growth conditions have been manoeuvred using the colligative properties of the mixture and thus higher growth temperature (~250 °C) could be attained that promoted larger grain growth. The beneficial influence of the capping agents (aniline and 1-octadecene) on the properties of chalcopyrite nanocrystals has enabled us to pictorally model the structural, morphological and optoelectronic aspects of CISe nanoparticles.

Without resorting to any post-selenization process and using the colligative properties of the mixture comprising of volatile aniline and non-volatile 1-octadecene to manoeuvre the growth conditions to promote Ostwald ripening, a single phase, monodispersive and nearly stoichiometric ternary CISe nanocrystals are formed by wet-synthesis route.Figure optionsDownload as PowerPoint slide