title: Synthesis, characterization and thermoluminescence studies of Mn-doped ZnS nanoparticles.
abstract: ZnS:Mn nanoparticles were prepared by a chemical precipitation method and characterized by X-ray diffraction (XRD), field emission gun scanning electron microscope (FEGSEM), and high resolution transmission electron microscopy (HRTEM). Capping agent (mercaptoethanol) concentrations used were 0 M, 0.005 M, 0.01 M, 0.015 M, 0.025 M, 0.040 M, and 0.060 M, and resulted in nanoparticles sizes of 2.98 nm, 2.9 nm, 2.8 nm, 2.7 nm, 2.61 nm, 2.2 nm and 2.1 nm, respectively. The thermoluminescence (TL) glow curve was recorded by heating the sample exposed to UV-radiation, at a fixed heating rate 1°C sec(-1). The TL intensity initially increased with temperature, attained a peak value Im for a particular temperature, and then decreased with further increase in temperature. The peak TL intensity increased with decreasing nanoparticle size, whereas the temperature corresponding to the peak TL intensity decreased slightly with reducing nanocrystal size. As a consequence of increase in surface-to-volume ratio and increased carrier recombination rates, the TL intensity increased with decreasing nanoparticle size. It was found that, whereas activation energy slightly decreased with decreasing nanoparticle size, the frequency factor decreased significantly with reduction in nanoparticle size.
authors.affiliation: School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur, 492010, (C.G.), India.
authors.forename: Raju Kumar
authors.initials: RK
authors.lastname: Chandrakar
authors.affiliation: School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur, 492010, (C.G.), India.
authors.forename: R N
authors.initials: RN
authors.lastname: Baghel
authors.affiliation: School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur, 492010, (C.G.), India.
authors.forename: B P
authors.initials: BP
authors.lastname: Chandra
mesh_terms: D049449:Luminescence; D008163:Luminescent Measurements; D008345:Manganese / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D013440:Sulfides / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; C031238:zinc sulfide
keywords: ZnS:Mn; activation energy; factor; frequency; nanoparticles; thermoluminescence