Patent Application
20080044590
The manufacturing method of a phosphor according to the present invention is characterized in that a metal organic compound solution for forming a phosphor is applied on a support, and the film is irradiated with an ultraviolet laser during the subsequent drying process, calcination process and baking process. A laser beam may be used as the ultraviolet radiation in the present invention.
Depending on the objective, the irradiation process may be performed during a prescribed process, or before or after the respective processes. Further, it is also possible to spin-coat the metal organic compound solution on a substrate, dry the substrate for solvent elimination in a thermostatic bath at 130° C., thereafter mount the sample on a sample holder in a laser chamber, and perform laser irradiation at room temperature.
In the present invention, as the metal for oxide to form a phosphor substance, a precursor film obtained by adding at least one element selected from a group comprised of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu to an oxide represented with a composition formula of ABO3, A2BO4, A3B2O7 (provided that there may be a deficiency at the A, B, O sites) wherein A is Ca, Sr and Ba, and B is Ti and Zr. One among Al, Ga and In may also be added thereto.
The present invention is also effective for a thin film containing minute amounts of conductive substances selected from In2O3, SnO2, ZnO and metal in advance.
As a result of irradiating laser on a film applied with a metal organic compound and thereafter dried and a film at the initial stage of calcinations, and thereafter performing appropriate thermal treatment to these laser irradiated films, for instance, the following effects were confirmed in the case of preparing a CaTiO3:Pr film.
After the process of applying and drying a metal organic compound solution for preparing a CaTiO3:Pr film on a support, by irradiating a laser beam at a temperature of 400° C. or lower after the calcination process of thermally decomposing the organic constituent in the metal organic compound at a temperature of 400° C., it has been discovered that crystallization is promoted at a low temperature.
With conventional thermal MOD process for the preparation of oxide film, as shown in
In the present invention, as the support, one type selected from organic substrate, glass substrate, polycrystalline and single crystalline oxide substrates such as strontium titanate (SrTiO3), lanthanum aluminate (LaAlO3), magnesium oxide (MgO), lanthalum strontium tantalum aluminum oxide ((LaxSr1-x)(AlxTa1-x)O3), neodymium gallate (NdGaO3), yttrium aluminate (YAlO3), aluminum oxide (Al2O3), yttria-stabilized zirconia ((Zr, Y)O2, YSZ) substrate may be used.
Specific examples of the present invention are now explained in detail below, but the present invention is not limited by these Examples in any way.
A quartz substrate and a non-alkali glass substrate were used as the substrate for the Examples in the present invention, and a solution obtained by mixing a 2-ethyl-1-hexanoate Ti solution to a strontium 2-ethylhexanoate solution was used as the raw material solution. Praseodium 2-ethylhexanoate was also used. KrF excimer laser, ArF excimer laser, and XeCl excimer laser were used for the irradiation of ultraviolet radiation.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a calcium 2-ethylhexanoate solution in a definite proportion to prepare a mixed solution (C1).
The C1 solution was spin-coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and at a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. The prepared film showed high luminescence intensity based on ultraviolet excitation only at the irradiated portion.
When the spin-coated film was irradiated with laser at a fluence of 100 mJ/cm2 in Example 1, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the spin-coated film was irradiated with laser at a fluence of 120 mJ/cm2 in Example 1, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the pulse rate of irradiation was set to 50 Hz in Example 1, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the pulse rate of irradiation was set to 10 Hz in Example 1, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the quartz substrate was replaced with an ITO/glass substrate (ITO coated on a glass substrate) in Example 1, a crystallized CaTiO3:Pr film was obtained at the irradiated portion. Further, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the quartz substrate was replaced with a non-alkali glass substrate in Example 1, only the irradiated portion showed high luminescence intensity based on ultraviolet excitation.
When the temperature of calcination to be performed after spin coating was set at 25 to 250° C. in Example 1, although only the irradiated portion showed high luminescence intensity based on ultraviolet excitation, the film crystallinity was inferior compared to a case when the calcination temperature was set to 400° C., and the increase of luminescence intensity after oxygenation was small. Thus, the calcination temperature is preferably around 400° C.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a calcium 2-ethylhexanoate solution at a ratio of Ca:Ti:Pr=1.997:1:0.002 to prepare a mixed solution (C2).
The C2 solution was spin coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the creation of a Ca2TiO4:Pr film was acknowledged by X-ray diffraction. The prepared film showed high luminescence intensity, equivalent to CaTiO3:Pr, based on ultraviolet excitation only at the irradiated portion.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a calcium 2-ethylhexanoate solution at a ratio of Ca:Ti:Pr=2.994:2:0.004 to prepare a mixed solution (C3).
The C3 solution was spin-coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the creation of a Ca3Ti2O7:Pr film was acknowledged by X-ray diffraction. The luminescence intensity of the prepared film was six times that of the CaTiO3:Pr film.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a strontium 2-ethylhexanoate solution at a ratio of Sr:Ti:Pr=0.998:1:0.002 to prepare a mixed solution (S1).
The S1 solution was spin-coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a SrTiO3:Pr film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
A 2-ethyl-1-hexanoate Ti solution, praseodium 2-ethylhexanoate, and an aluminum acetylacetonate solution were added to a strontium 2-ethylhexanoate solution at a ratio of Sr:Ti:Pr:Al 1:1:0.002:0.15 to prepare a mixed solution (S2).
The S2 solution was spin-coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a SrTiO3:Pr,Al film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a strontium 2-ethylhexanoate solution at a ratio of Sr:Ti:Pr=2:1:0.002 to prepare a mixed solution (S3).
The S3 solution was spin coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a Sr2TiO4:Pr film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
A 2-ethyl-1-hexanoate Ti solution and praseodium 2-ethylhexanoate were added to a strontium 2-ethylhexanoate solution at a ratio of Sr:Ti:Pr=3:2:0.004 to prepare a mixed solution (S4).
The S4 solution was spin coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a Sr3Ti2O7:Pr film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
A strontium 2-ethylhexanoate solution, a 2-ethyl-1-hexanoate Ti solution, and praseodium 2-ethylhexanoate were added to a calcium 2-ethylhexanoate solution at a ratio of Ca:Sr:Ti:Pr=2:1:2:0.002 to prepare a mixed solution (S5).
The S5 solution was spin coated on a quartz substrate at 4000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a (Ca, Sr)3Ti2O7:Pr film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
The C1 solution was spin coated on a quartz substrate at 4000 rpm for 10 seconds, and irradiated with an ultraviolet lamp at room temperature for 10 minutes. Subsequently, the substrate temperature was retained at 250° C. and the spin-coated film was irradiated with a pulsed laser of 248 nm, 20 Hz, and a fluence of 80 mJ/cm2 in the atmosphere for 5 minutes. As a result, the formation of a CaTiO3:Pr film was identified by X-ray diffraction. Only the irradiated portion of the prepared film emitted light.
The C1 solution was spin-coated on a quartz substrate at 3000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. As a result, the deposited film did not emit light.
The C1 solution was spin-coated on non-alkali glass at 3000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. As a result, the deposited film did not emit light.
The C1 solution was spin-coated on an ITO/quartz substrate at 3000 rpm for 10 seconds, and heated at 400° C. for 10 minutes. As a result, the deposited film did not emit light.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-224627 | Aug 2006 | JP | national |
