Target for ultraviolet light generation, electron beam-excited ultraviolet light source, and production method for target for ultraviolet light generation
A target for ultraviolet light generation comprises a substrate adapted to transmit ultraviolet light therethrough and a light-emitting layer disposed on the substrate and generating ultraviolet light in response to an electron beam. The light-emitting layer includes a polycrystalline film constituted by an oxide polycrystal containing Lu and Si doped with an activator or a polycrystalline film constituted by a rare-earth-containing aluminum garnet polycrystal doped with an activator.
1. A target for ultraviolet light generation comprising:
a substrate adapted to transmit ultraviolet light therethrough; and
a light-emitting layer disposed on the substrate and generating ultraviolet light in response to an electron beam;
wherein the light-emitting layer includes a polycrystalline film constituted by an oxide polycrystal containing Lu and Si doped with an activator.
2. A target for ultraviolet light generation according to claim 1 , wherein the oxide polycrystal includes at least one of LPS and LSO.
3. A target for ultraviolet light generation according to claim 2 , wherein the activator is Pr.
4. A target for ultraviolet light generation according to claim 1 , wherein the polycrystalline film has a thickness of at least 0.1 μm but not more than 10 μm.
5. A target for ultraviolet light generation according to claim 1 , wherein the substrate is constituted by sapphire, silica, or rock crystal.
6. An electron-beam-excited ultraviolet light source comprising:
the target for ultraviolet light generation according to claim 1 ; and
an electron source providing the target with the electron beam.
7. A target for ultraviolet light generation comprising:
a substrate adapted to transmit ultraviolet light therethrough; and
a light-emitting layer disposed on the substrate and generating ultraviolet light in response to an electron beam;
wherein the light-emitting layer includes a polycrystalline film constituted by a rare-earth-containing aluminum garnet polycrystal doped with an activator, the polycrystalline film having an ultraviolet light emission peak wavelength of 300 nm or shorter.
8. A target for ultraviolet light generation according to claim 7 , wherein the rare-earth-containing aluminum garnet polycrystal is LuAG, while the activator is at least one of Sc, La, and Bi.
9. A target for ultraviolet light generation according to claim 7 , wherein the rare-earth-containing aluminum garnet polycrystal is YAG, while the activator is at least one of Sc and La.
10. A target for ultraviolet light generation according to claim 7 , wherein the polycrystalline film has a thickness of at least 0.1 μm but not more than 10 μm.
11. A target for ultraviolet light generation according to claim 7 , wherein the substrate is constituted by sapphire, silica, or rock crystal.
12. An electron-beam-excited ultraviolet light source comprising:
the target for ultraviolet light generation according to claim 7 ; and
an electron source providing the target with the electron beam.
13. A method for manufacturing a target for ultraviolet light generation, the method comprising:
a first step of vapor-depositing an activator and an oxide containing Lu and Si on a substrate adapted to transmit ultraviolet light therethrough, so as to form a film; and
a second step of turning the film into a polycrystal by heat treatment.
14. A method for manufacturing a target for ultraviolet light generation according to claim 13 , wherein the surroundings of the film are at an atmospheric pressure during the heat treatment in the second step.
15. A method for manufacturing a target for ultraviolet light generation according to claim 13 , wherein the film has a thickness of at least 0.1 μm but not more than 10 μm after the heat treatment in the second step.
16. A method for manufacturing a target for ultraviolet light generation, the method comprising:
a first step of vapor-depositing an activator having an ultraviolet light emission peak wavelength of 300 nm or shorter and a material for a rare-earth-containing aluminum garnet crystal, so as to form a film; and
a second step of turning the film into a polycrystal by heat treatment.
17. A method for manufacturing a target for ultraviolet light generation according to claim 16 , wherein the surroundings of the film are in a vacuum during the heat treatment in the second step.
18. A method for manufacturing a target for ultraviolet light generation according to claim 16 , wherein the film has a thickness of at least 0.1 μm but not more than 10 μm after the heat treatment in the second step.