Studies on Size Dependent Structures and Optical Properties of CdSeS Clusters

TL;DR

This study investigates the size-dependent structures and optical properties of CdSeS nanoclusters using DFT/TDDFT, revealing their stability, hyperpolarizability, and potential as nonlinear optical quantum dots, with experimental validation via UV-Vis spectroscopy.

Contribution

It provides new insights into the size-dependent stability and optical properties of CdSeS clusters, highlighting their nonlinear optical activity and potential applications as quantum dots.

Findings

CdSeS clusters are more hyperpolarizable than CdX clusters.

Structure influences response properties, especially for clusters with n>3.

Cd4Se_mS_p clusters are identified as nonlinear optical quantum dots.

Abstract

The size-dependent structures and optical properties of CdSeS nanoclusters in water medium are investigated. The stability of different size-dependent Cd$_n$Se$_m$S$_p$ nanoclusters (up to n=6) is studied using density functional theory/time-dependent density functional theory (DFT/TDDFT). The computed results for ground (S$_0$) and excited (S$_1$, S$_2$, S$_3$) states are experimentally verified through UV-Vis spectroscopy. Computed ab initio results suggest that CdSeS clusters are significantly more hyperpolarizable compared to CdX (X= S, Se, Te) clusters. Structure dependent response properties are also observed, especially for n>3. Larger hyperpolarizabilities ($\beta$ and$\gamma$), charge variation and orbital analysis establish Cd$_4$Se$_m$S$_p$ clusters, as nonlinear optically active quantum dots (QDs).