Manganese doped zinc sulphide nanoparticles by aqueous method

Abstract

Zinc sulphide nanoparticles in the size range ∼10–40 Å diameter have been synthesized using the aqueous chemical method. Scanning tunneling microscopy showed that particles are indeed nanosize particles. The size dependent band gap could be varied from a bulk value of 3.68 to 4.5 eV. X-ray diffraction indicated that nanoparticles are crystalline except for those with band gap ∼4.5±0.1 eV. Nanoparticles with particle size ∼21×2 Å diameter or energy gap 4.1×0.1 eV were doped with manganese. The photoluminescence peak at ∼600 nm corresponding to yellow light emission was observed. Atomic absorption studies show that maximum luminescence intensity is achievable with 0.12 at. wt % of Mn doping.

Factors Influencing the Luminescence Quantum Efficiency of Nanocrystalline ZnS:Mn2+

“…In contrast to what has been published before [2][3][4] no concentration quenching was observed. Previous reports stated that concentration quenching was observed at Mn 2+ concentrations of 0.12 at% Mn [3] and 1 at% Mn [4] incorporated in the nanoparticle.…”

“…Previous reports stated that concentration quenching was observed at Mn 2+ concentrations of 0.12 at% Mn [3] and 1 at% Mn [4] incorporated in the nanoparticle. Possibly, the earlier reported decrease in quantum efficiency with increasing Mn content was not due to the increase Mn-concentration, but to other factors which influence the quantum efficiency (e.g.…”

“…Bhargava et al [1] reported that with decreasing particle size the quantum efficiency increases from 1% for particles of 7 nm to 18% for particles of 3.5 nm due to quantum size effects. Other researchers [2][3][4] have found that the quantum efficiency of nanocrystalline ZnS : Mn 2+ is dependent on the Mn 2+ concentration. Besides, several papers have appeared in which it was reported that the quantum efficiency of nanocrystalline ZnS and ZnS : Mn 2+ was enhanced by irradiation of the samples with UV [5][6][7][8][9].…”

A simple one Step Thermochemical Approach for Synthesis of ZnS:Mn Nanocrystals (NCs)

“…Maity and Chattopadhyay [18] found an optimal Mn +2 concentration of 0.07%. Khosravi et al [19] observed a maximum luminescence at a doping concentration of 0.12 wt%. Leeb et al [20] reported an optimal Mn +2 concentration of 1%.…”

A Review on Zinc Sulphide Nanoparticles: From Synthesis, Properties to Applications

“…In this paper they have measured PL emission for various excitation wavelengths. They observed a broad peak at about 363 nm (3.41 eV) for all samples in the PL spectra for all organic passivating agents at 220 nm excitation wavelength [2].…”