Absorption and Radiation Transitions in Mn2+(3d5) Configuration of Mn-Doped ZnS Nanoparticles Synthesized by a Hydrothermal Method. (21st April 2013)

• Record Type: Journal Article
• Authors: Van, Bui Hong; Ben, Pham Van; Thi, Tran Minh; Nhat, Hoang Nam
• Other Names: Ferrari Maurizio Academic Editor.
• Is Part Of: Journal of materials. Volume 2013(2013)
• Publication Date: 2013-04-21
• Subjects: Materials -- Periodicals; Materials; Periodicals; 620.11
• DOI: 10.1155/2013/716452
• Languages: English
• ISSNs: 2314-4866

Abstract

Abstract : The Mn-doped ZnS nanoparticles with Mn content of 0–15 mol% were synthesized by a hydrothermal method from the solutions Zn(CH3 COO)2 0.1 M, Mn(CH3 COO)2 0.01 M, and Na2 S2 O3 0.1 M at 220°C for 15 h. These nanoparticles presented the cubic structure with average particle size about 16 nm. The yellow-orange photoluminescence (PL) band at 586 nm was attributed to the radiation transition of the electrons in 3d 5 unfilled shell of Mn 2+ ions [ 4 T1 ( 4 G)- 6 A1 ( 6 S)] in ZnS matrix. The photoluminescence excitation (PLE) spectra monitored at the yellow-orange band, the absorption spectra also showed the near band edge absorption of 336–349 nm and the characteristic absorption bands of Mn 2+ (3d 5 ) ions at 392, 430, 463, 468, 492, and 530 nm. These bands should be attributed to the absorption transitions of 3d 5 electrons from the ground state 6 A1 ( 6 S) to the excited states 4 E( 4 D), 4 T2 ( 4 D), 4 A1 ( 4 G)- 4 E( 4 G), 4 T2 ( 4 G), and 4 T1 ( 4 G) of Mn 2+ ions. The intensity of PL band and absorption bands of Mn 2+ (3d 5 ) ions also increased with the Mn content from 0.1 to 9 mol%, but their peak positions were almost unchanged. The PLE spectra showed clearly the energy level splitting of Mn 2+ ions in ZnS crystal field and allowed for the calculation of the splitting width between the excited states 4 A1 ( 4 G), 4 E( 4 G) about of 229 cm −1 (28.6 meV), and the Racah parameters B = 559 cm −1, C = 3202 cm −1 ( γ = C / B = 5.7 ), and the crystal field strength D q = 568 cm −1 . The PL spectra with different excitation wavelengths corresponding to absorption transition bands of the PLE spectra allow for the discussion of the indirect and direct excitation mechanisms of Mn 2+ (3d 5 ) ions in the ZnS crystal.