Glycothermal Synthesis of ZnGa[sub 2]O[sub 4]:Mn[sup 2+] Nanophosphor and Change in Its Photoluminescence Intensity by Heat-Treatment

Abstract

ZnGa 2 O 4 :Mn 2+ nanophosphors were synthesized from zinc acetate dihydrate, gallium acetylacetonate, and manganese͑II͒ acetate tetrahydrate in 1,4-butanediol by glycothermal method at 300°C for 2 h. Their average particle diameter was 12.1 ± 2.5 nm. We investigated the influence of temperatures of postheat-treatment in Ar on the luminescent and structural properties. The photoluminescence ͑PL͒ intensity slightly decreased after heating below 900°C. The PL intensity increased between 900 and 1200°C, reached at the maximum at 1200°C and decreased over 1200°C. The decrease of the PL intensity by heating below 900°C occurred by the removal of adsorbed organic species. The X-ray diffraction profile indicated the decomposition of ZnGa 2 O 4 to Ga 2 O 3 and ZnO by heating over 1200°C, resulting in the decrease of the PL intensity. The change in the integrated intensity of electron paramagnetic resonance due to paramagnetic Mn 2+ with the temperature of heat-treatment in Ar was similar to that of the PL intensity. This suggests that the PL intensity is correlated to the incorporated Mn 2+ amount.

Size-Tunable Solvothermal Synthesis of Zn2GeO4:Mn2+Nanophosphor in Water/Diethylene Glycol System

“…23 Two peaks at 1438 and 1561 cm -1 (peaks 6 and 7) are assigned to the symmetric and asymmetric stretching vibration modes of carboxyl groups, respectively, derived from acetate ions. 37,38 These are characteristic of carboxyl groups coordinating to metal ions at the surface of the particles. A small peak at 1022 cm -1 (peak 3) is assigned to the stretching vibration modes of C-C and C-O bonds in acetate ions.…”

Low-voltage cathodoluminescence properties of green-emitting ZnAl2O4:Mn2+ nanophosphors for field emission display

“…Therefore, it has been successfully used in flat-panel displays as a low-voltage oxide phosphor [3][4][5][6][7]. However, the high cost of source materials containing Ga limits its application to optical devices.…”

Emission properties of Zinc Gallate nanophosphors

“…20) However, the spectrum in Fig. 5(a) 34) Synthesis by combustion with an organic-containing precursor is known to provide a large number of oxygen vacancies, resulting in emission peak at 680 nm (1.82 eV). 35) Based on these facts, it can be said that it is more probable for nano-sized ZnGa 2 O 4 to provide white emission than micron-sized ones.…”