Microbe-Assisted Synthesis and Luminescence Properties of Monodispersed Tb3+-Doped ZnS Nanocrystals

Zhanguo Liang,Hongquan Yu,Jun Mu,Lei Han

doi:10.1155/2015/519303

Zhanguo Liang, Hongquan Yu + Show 2 more

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https://doi.org/10.1155/2015/519303

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Abstract

Tb3+-doped zinc sulfide (ZnS:Tb3+) nanocrystals were synthesized by spray precipitation with sulfate-reducing bacterial (SRB) culture at room temperature. The morphology of the SRB and ZnS:Tb3+nanocrystals was examined by scanning electron microscopy, and the ZnS:Tb3+nanocrystals were characterized by X-ray diffractometry and photoluminescence (PL) spectroscopy. The PL mechanism of ZnS:Tb3+nanocrystals was further analyzed, and the effects of Tb3+ion concentration on the luminescence properties of ZnS:Tb3+nanocrystals were studied. ZnS:Tb3+nanocrystals showed a sphalerite phase, and the prepared ZnS:Tb3+nanocrystals had high luminescence intensity under excitation at 369 nm. The main peak position of the absorption spectra positively blueshifted with increasing concentrations of Tb3+dopant. Based on the strength of the peak of the excitation and emission spectra, we inferred that the optimum concentration of the Tb3+dopant is 5 mol%. Four main emission peaks were obtained under excitation at 369 nm:489 nm (5D4→7F6), 545 nm (5D4→7F5), 594 nm (5D4→7F4), and 625 nm (5D4→7F3). Our findings suggest that nanocrystals have potential applications in photoelectronic devices and biomarkers.

Highlights

Zinc sulfide (ZnS) is one of the most important II–IV semiconductors with a band gap of approximately 3.6 eV [1] and is commercially used as a phosphor and thin film in electroluminescent devices
Since Bhargava et al first reported the remarkable optical properties of Mn-doped ZnS nanocrystals prepared by chemical process at room temperature in 1994 [6, 7], a large number of investigations on semiconductor nanocrystals have focused on the photoluminescence properties of Mn-doped ZnS nanocrystals [8,9,10,11,12,13,14,15,16], Cu-doped ZnS nanocrystals [9, 17], Sm-doped ZnS nanocrystals [18], Tb-doped ZnS nanocrystals [18,19,20], and Eu-doped ZnS nanocrystals [21,22,23,24,25] prepared by different techniques [26]
ZnS:Tb3+ nanocrystals were synthesized by the direct precipitation and spray precipitation methods with sulfatereducing bacterial (SRB) culture (Figures 2(a), 2(b), 2(c), 2(d), 2(e), 2(f), and 2(g))

Summary

Introduction

Zinc sulfide (ZnS) is one of the most important II–IV semiconductors with a band gap of approximately 3.6 eV [1] and is commercially used as a phosphor and thin film in electroluminescent devices. Since Bhargava et al first reported the remarkable optical properties of Mn-doped ZnS nanocrystals prepared by chemical process at room temperature in 1994 [6, 7], a large number of investigations on semiconductor nanocrystals have focused on the photoluminescence properties of Mn-doped ZnS nanocrystals [8,9,10,11,12,13,14,15,16], Cu-doped ZnS nanocrystals [9, 17], Sm-doped ZnS nanocrystals [18], Tb-doped ZnS nanocrystals [18,19,20], and Eu-doped ZnS nanocrystals [21,22,23,24,25] prepared by different techniques [26] These papers, do not report on ZnS:Tb3+ nanocrystals synthesized by spray precipitation method in sulfatereducing bacterial (SRB) culture at room temperature

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