S. Ananthakumar

Cesium lead halide ( CsPbX 3, X = Cl , Br, I) perovskite quantum dots-synthesis, properties, and applications: a review of their present status

Abstract. Metal halide-based perovskite quantum dots (QDs) have emerged as promising materials for optoelectronics and future energy applications. Among them, cesium lead halide-based perovskite quantum dots (Cs-LHQDs) have been found to be potential luminescent candidates and alternatives for the II–VI and I−III−VI2 groups semiconductor nanoparticles. These perovskites provide an excellent quantum yield (90%) larger than any other semiconductor QDs. At present, synthesis of Cs-LHQDs has been successfully achieved through a traditional colloidal-based hot-injection method and a room temperature precipitation method. Some of the interesting results in their structural, optical, and morphological properties are being analyzed to understand their energy-transfer mechanism in the colloidal state. Morphology of nanoplates, nanowires, nanocube, and nanosheets in these materials confirms their physical parameters-dependent self-assembly nature in a colloidal medium. Their potential use for light emitting diodes, photodetectors, and lasers is also highly motivated. This review provides a collective view of recent developments made in the synthesis of Cs-LHQDs and their properties.

Colloidal synthesis and characterization of Cu2ZnSnS4 nanoplates

Synthesis of copper zinc tin sulphide (Cu 2 ZnSnS 4 ) with nanoplate morphology was achieved through colloidal method using oleic acid as capping agent and solvent with 1-octadecene (1-ODE) at 240℃. X-ray diffraction (XRD) analysis shows that the synthesized nanoplates possessed pure kesterite phase. SEM analysis clearly shows the formation of nanoplates having the size of about 50-100 nm. Electron spin resonance (ESR) spectrum analysis of the prepared nanoplates shows that the valence state of copper (Ⅱ) which indicates the strong coupling with other metal ions. Thermo gravimetric/differential thermal analysis (TG/DTA) analysis shows the weight loss of sample at 450℃ predicting the loss of capping ligands on the surface of the nanoparticles. The possible mechanism for the conversion of nanoplate-like structures during synthesis was discussed. The results are discussed in detail.

Enhanced light absorption in CdTe nanoparticles/P3HT nanofiber blends

Colloidal cadmium telluride (CdTe) nanoparticles were synthesized in aqueous medium and it was transferred into organic medium through surface treatment process by a thiol. The prepared particles were blended with P3HT nanofibers and the blend was studied using UV-Visible spectroscopy. The P3HT fibers were formed in the presence of the poor solvent acetone through simple mixed solvent approach. The size of the particles and morphology of the fibers were analysed using TEM and SEM. Solvatochromic shift was observed in the spectra for pristine P3HT and P3HT fiber polymer in chloroform due to the crystallization of highly interconnected P3HT chains. The fiber structure of the P3HT polymer/CdTe nanoparticles blends shows greater absorption than the pristine P3HT/CdTe nanoparticles blend.