IMPACT OF NEW CHLOROTRIAZINE LIGANDS ON THE PHOTO PHYSICAL PROPERTIES ON CSPbBr3 QUANTUM DOTS

Abstract

This study investigates the influence of a newly synthesized chlorotriazine ligand on the photophysical properties of cesium lead bromide (CsPbBr₃) nanocrystals (NCs). Control NCs were prepared with oleic acid/oleylamine capping, while chlorotriazine modification was introduced through both post-synthetic ligand exchange and direct synthesis approaches. Structural and surface analyses confirmed successful ligand binding via coordination with surface Pb²⁺ and Br⁻ sites. Optical characterization revealed a slight band gap blue shift from 2.38 to 2.40 eV, accompanied by a sharper absorption edge, reduced Urbach energy, and suppression of sub-gap states, indicative of improved surface passivation. Time-resolved photoluminescence demonstrated longer carrier lifetimes and reduced non-radiative recombination in chlorotriazine-functionalized NCs compared to controls. These improvements highlight the role of chlorotriazine in stabilizing surface chemistry, enhancing photoluminescence efficiency, and improving resistance to optical degradation. The findings establish that subtle ligand-driven modifications can significantly tune the optoelectronic performance of CsPbBr₃ nanocrystals, offering pathways for their optimized application in light-emitting diodes, lasers, and photovoltaic devices.