ZnS:Mn (CMn = 5 %mol) nanoparticles have been synthesized by a hydrothermal method from solutions of Zn(CH3COO)2 M, Na2S2O3 M and Mn(CH3COO)2 M at 220oC for different reaction time. The result showed that increasing reaction time from 3 to 30h almost does not change cubic crystalline structure, peak positions attributed to Mn2+ ions at 585 nm in photoluminescence spectra and 392, 430, 463, 468, 492 nm in photoluminescence excitation spectra when monitoring the 585 nm band of ZnS:Mn nanoparticles but only slight increases lattice constant, the average particle size and changing their intensity. | VNU Journal of Science: Mathematics – Physics, Vol. 33, No. 1 (2017) 81-85 Influence of Reaction Time on Optical Property of ZnS:Mn Nanoparticles Synthesized by a Hydrothermal Method Pham Van Ben, Bui Hong Van* Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Hanoi, Vietnam Received 05 January 2017 Revised 16 February 2017; Accepted 20 March 2017 Abstract: ZnS:Mn (CMn = 5 %mol) nanoparticles have been synthesized by a hydrothermal method from solutions of Zn(CH3COO)2 M, Na2S2O3 M and Mn(CH3COO)2 M at 220oC for different reaction time. The result showed that increasing reaction time from 3 to 30h almost does not change cubic crystalline structure, peak positions attributed to Mn 2+ ions at 585 nm in photoluminescence spectra and 392, 430, 463, 468, 492 nm in photoluminescence excitation spectra when monitoring the 585 nm band of ZnS:Mn nanoparticles but only slight increases lattice constant, the average particle size and changing their intensity. As increasing the reaction time from 3 to 10h, intensity of bands attributed to Mn2+ ions also increase, reaches the maximum at 15h and then decreases as increasing reaction time to 30 h. Cause of these phenomena have been investigated and reported. Keywords: Nanoparticles, photoluminescence, photoluminescence excitation. 1. Introduction With the prominent features wide band gap, direct transition, strong luminescence in the yelloworange region, ZnS:Mn nanomaterial has been widely applied in optoelectronic devices, bio-label, photo-catalyst [1-3]. ZnS:Mn nanoparticles may be prepared by some methods such as chemical vapor deposition, microwave, hydrothermal, [4], in which, by hydrothermal method, the morphology and particle size can be controlled by changing the reaction time and temperature. Therefore, some optical properties of them will be changed. In this paper, ZnS:Mn nanoparticles with the Mn content of 5 %mol have been prepared by the hydrothermal method at 220oC for reaction .
