The goal of this work is to obtain ensemble-averaged description of excitonic properties of colloidal semiconductor quantum dots at non-zero temperature. The investigation was performed using the canonical ensemble, and the sampling was performed using equilibrium molecular dynamics in the presence of explicit solvent (water) molecules. A range of semiconductor material types (CdS, CdSe, PbS, PbSe, ZnSe) were investigated, and the QD-solvent interaction was treated using QM/MM method. A set of QD structures were randomly selected from the equilibrated MD trajectories and excitonic properties such as exciton binding energies and electron-hole recombination probabilities were computed using the electron-hole explicitly correlated Hartree-Fock method. The results from these calculations were used to generate temperature-dependent distribution of the excitonic properties and calculation of ensemble-averaged expectation values. The impact of choice of material type (CdS, CdSe, PbS, PbSe, ZnSe) and dot size (1-5 nm) was investigated and will be presented. The results from this study show the importance of including the solvent environment in the determination of excitonic properties. The results also highlight the limitations of using minimum energy structures (0 K geometry) for predicting optical and electronic properties of semiconductor nanoparticles.<br/> <br/>

Effect of temperature on excitonic properties in colloidal quantum dots

256th National Meeting (2018)

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