A DFT study for the structural and electronic properties of Zn m Se n nanoclusters

Phool Singh Yadav,Dheeraj Kumar Pandey

doi:10.1007/s13204-012-0091-y

Phool Singh Yadav, Dheeraj Kumar Pandey

Open Access

https://doi.org/10.1007/s13204-012-0091-y

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Journal: Applied Nanoscience	Publication Date: Apr 5, 2012
Citations: 10	License type: cc-by

Affiliation: University of Allahabad

Abstract

An ab initio study has been performed for the stability, structural and electronic properties of 19 small zinc selenide ZnmSen (m + n = 2–4) nanoclusters. Out of these nanoclusters, one nanocluster is found to be unstable due to its imaginary vibrational frequency. A B3LYP-DFT/6-311G(3df) method is used in the optimization of the geometries of the nanoclusters. We have calculated the zero point energy (ZPE), which is ignored by the other workers. The binding energies (BE), HOMO–LUMO gaps and bond lengths have been obtained for all the optimized nanoclusters. For the same value of ‘m’ and ‘n’, we designate the most stable structure the one, which has maximum final binding energy (FBE) per atom. The adiabatic and vertical ionization potentials (IP) and electron affinities (EA), dipole moments and charge on atoms have been investigated for the most stable nanoclusters. For the same value of ‘m’ and ‘n’, the nanocluster containing maximum number of Se atoms is found to be most stable.

Highlights

The period for more than three decades has drawn significant attention to explore the physics and chemistry of II–VI semiconductor nanoclusters (Alivisatos 1996; Murray et al 2000; Trindade et al 2001; Efros and Rosen 2000; Hagfeldt and Gratzel 1995; Brus 1984)
We report the results of a theoretical study of the structural, stabilities, HOMO–LUMO gap, adiabatic and vertical ionization potential (IP) and electron affinity (EA), charge on atoms and dipole moment of small size ZnmSen (m ? n = 2–4) nanoclusters by using the B3LYP-DFT/6-311G(3df) method
The value of HOMO–LUMO gap increases with number of Se atoms, except for the twoatom ZnSe nanocluster

Summary

Introduction

The period for more than three decades has drawn significant attention to explore the physics and chemistry of II–VI semiconductor nanoclusters (Alivisatos 1996; Murray et al 2000; Trindade et al 2001; Efros and Rosen 2000; Hagfeldt and Gratzel 1995; Brus 1984). Most recently, Sanville et al (2006) produced the ZnSe nanoclusters by direct laser ablation method and analyzed in a time of flight mass spectrometer. They predicted only few physical properties like atomization energy, HOMO–LUMO gap and vertical ionization potential of small stoichiometric ZnnSen (n = 1–16) nanocluster at B3LYP level of theory using SKBJ (d, 2df) basis set. We report the results of a theoretical study of the structural, stabilities, HOMO–LUMO gap, adiabatic and vertical ionization potential (IP) and electron affinity (EA), charge on atoms and dipole moment of small size ZnmSen

Methods

Conclusions