Electronic and Optical Properties of Small Hydrogenated Silicon Quantum Dots Using Time-Dependent Density Functional Theory

Muhammad Mus Ab Anas, Geri Kibe Gopir

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

This paper presents a systematic study of the absorption spectrum of various sizes of small hydrogenated silicon quantum dots of quasi-spherical symmetry using the time-dependent density functional theory (TDDFT). In this study, real-time and real-space implementation of TDDFT involving full propagation of the time-dependent Kohn-Sham equations were used. The experimental results for SiH4 and Si5H12 showed good agreement with other earlier calculations and experimental data. Then these calculations were extended to study larger hydrogenated silicon quantum dots with diameter up to 1.6 nm. It was found that, for small quantum dots, the absorption spectrum is atomic-like while, for relatively larger (1.6 nm) structure, it shows bulk-like behavior with continuous plateau with noticeable peak. This paper also studied the absorption coefficient of silicon quantum dots as a function of their size. Precisely, the dependence of dot size on the absorption threshold is elucidated. It was found that the silicon quantum dots exhibit direct transition of electron from HOMO to LUMO states; hence this theoretical contribution can be very valuable in discerning the microscopic processes for the future realization of optoelectronic devices.

Original languageEnglish
Article number481087
JournalJournal of Nanomaterials
Volume2015
DOIs
Publication statusPublished - 2015

Fingerprint

Silicon
Electronic properties
Semiconductor quantum dots
Density functional theory
Optical properties
Absorption spectra
Electron transitions
Optoelectronic devices
Electrons

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Electronic and Optical Properties of Small Hydrogenated Silicon Quantum Dots Using Time-Dependent Density Functional Theory. / Anas, Muhammad Mus Ab; Gopir, Geri Kibe.

In: Journal of Nanomaterials, Vol. 2015, 481087, 2015.

Research output: Contribution to journalArticle

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