Pulsed Laser Deposition 방법으로 증착시킨 Se가 첨가된 ZnGa2O4:Mn2+ 박막 형광체의 형광 특성 = Luminescent Characteristics of Se-doped ZnGa2O4:Mn2+ Thin Film Phosphors Grown by Pulsed Laser Deposition

다국어 초록 (Multilingual Abstract)

Mn-doped ZnGa$_2$O$_{4-x}$Se$_x$ thin-film phosphors were grown
using pulsed laser deposition (PLD) under various growth conditions. A structural characterization was carried out on a series of ZnGa$_2$O$_{4-x}$Se$_x$ : Mn$^{2+}$ films grown on MgO (100) substrates by using Zn-rich ceramic targets. Zn-rich ceramic targets were prepared to compensate for the vaporization loss of Zn during PLD. The substrate temperature was fixed at 600 $^\circ$C and the oxygen pressure was varied from 50 to 200 mTorr. The luminescence results indicated that MgO (100) is a promising substrate for the growth of high-quality of ZnGa$_2$O$_{4-x}$Se$_x$ : Mn$^{2+}$ films. The crystallinity and the surface roughness of the ZnGa$_2$O$_{4-x}$Se$_x$ : Mn$^{2+}$ films were highly dependent on the oxygen pressure. Epitaxial films were obtained on MgO (100) substrates due to the low lattice mismatch between ZnGa$_2$O$_4$ and MgO. The crystallinity of the films was improved with Se doping. The root-mean-square surface roughness of these ZnGa$_2$O$_{4-x}$Se$_x$ : Mn$^{2+}$ films was found to initially increase from 3.25 nm at x = 0.00 to 10.92 nm at x = 0.075 then decrease to 8.43 nm at x = 0.10 as the amount of Se was increased. Incorporation of Se into the ZnGa$_2$O$_4$ lattice led to a remarkable increase into photoluminescence. The
highest green emission intensity was observed with ZnGa$_2$O$_4$Se$_x$ : Mn$^{2+}$ (x = 0.075) films whose brightness was increased by a factor of 3.1 in comparison with that of ZnGa$_2$O$_4$ : Mn$^{2+}$ films. This phosphor is promising for applications in flat panel displays.