Flexible radiation detectors
Disclosed is a flexible radiation detector including a substrate, a switching device on the substrate, an energy conversion layer on the switching device, a top electrode layer on the energy conversion layer, a first phosphor layer on the top electrode layer, and a second phosphor layer under the substrate.
1. A flexible radiation detector, comprising:
a substrate;
a switching device on the substrate;
an energy conversion layer on the switching device;
a top electrode layer on the energy conversion layer;
a first phosphor layer on the top electrode layer; and
a second phosphor layer under the substrate,
wherein the first phosphor layer comprises:
a first layer; and
a second layer,
wherein the first layer is disposed between the second layer and the top electrode layer, and the second layer is thicker than the first layer,
wherein the first layer comprises a first phosphor powder consisting of phosphor particles having a first average particle diameter dispersed in a first resin, the second layer comprises a second phosphor powder consisting of phosphor particles having a second average particle diameter dispersed in a second resin, and the first average particle diameter is greater than the second average particle diameter, such that an X-ray conversion efficiency of the first layer is greater than that of the second layer,
wherein the first average particle diameter is about 10 μm to 20 μm, and the second average particle diameter is about 0.1 μm to 10 μm.
2. The flexible radiation detector as claimed in claim 1 , wherein the second phosphor layer comprises a phosphor powder dispersed in a resin.
3. The flexible radiation detector as claimed in claim 2 , wherein the first phosphor powder, the second phosphor powder, and the phosphor powder of the second phosphor layer absorb an X-ray and emit a visible light and/or an ultraviolet light.
4. The flexible radiation detector as claimed in claim 1 , wherein particles of the first phosphor powder near the top electrode layer have a diameter larger than that of particles of the first phosphor powder distant from the top electrode layer, and particles of the second phosphor powder near the top electrode layer have a diameter larger than that of particles of the second phosphor powder distant from the top electrode layer.
5. The flexible radiation detector as claimed in claim 1 , wherein the first phosphor layer further comprises a fifth layer disposed between the first layer and the second layer, the fifth layer is thicker than the first layer, and the fifth layer is thinner than the second layer.
6. The flexible radiation detector as claimed in claim 5 , wherein the fifth layer comprises a fifth phosphor powder consisting of phosphor particles having a fifth average particle diameter dispersed in a fifth resin, the fifth average particle diameter being less than the first average particle diameter, and greater than the second average particle diameter.
7. The flexible radiation detector as claimed in claim 6 , wherein the fifth average particle diameter is about 5 μm to 15 μm.
8. The flexible radiation detector as claimed in claim 1 , wherein the second phosphor layer comprises:
a third layer; and
a fourth layer,
wherein the third layer is disposed between the fourth layer and the substrate, and the fourth layer is thicker than the third layer.
9. The flexible radiation detector as claimed in claim 8 , wherein the third layer comprises a third phosphor powder consisting of phosphor particles having a third average particle diameter dispersed in a third resin, the fourth layer comprises a fourth phosphor powder consisting of phosphor particles having a fourth average particle diameter dispersed in a fourth resin, and the third average particle diameter is greater than the fourth average particle diameter.
10. The flexible radiation detector as claimed in claim 9 , wherein the third average particle diameter is about 10 μm to 20 μm and the fourth average particle diameter is about 0.1 μm to 10 μm.
11. The flexible radiation detector as claimed in claim 9 , wherein the second phosphor layer further comprises a sixth layer disposed between the third layer and the fourth layer, the sixth layer is thicker than the third layer, and the sixth layer is thinner than the fourth layer.
12. The flexible radiation detector as claimed in claim 11 , wherein the sixth layer comprises a sixth phosphor powder consisting of phosphor particles having a sixth average particle diameter dispersed in a sixth resin, the sixth average particle diameter is less than the third average particle diameter, and greater than the fourth average particle diameter.
13. The flexible radiation detector as claimed in claim 12 , wherein the sixth average particle diameter is about 5 μm to 15 μm.
14. The flexible radiation detector as claimed in claim 1 , wherein the energy conversion layer has a thickness of about 1 μm to 25 μm.
15. The flexible radiation detector as claimed in claim 1 , wherein the energy conversion layer is a single-layered structure of semiconductor material, or a multi-layered structure of semiconductor materials, wherein the multi-layered structure comprises a P-I-N structure, an I-P structure, or an I-N structure.
16. The flexible radiation detector as claimed in claim 1 , wherein the energy conversion layer transfers an ultraviolet or visible light to electrons and holes.
17. The flexible radiation detector as claimed in claim 1 , wherein the substrate has a thickness of about 10 μm to 20 μm.
18. The flexible radiation detector as claimed in claim 1 , further comprising a reflective layer or an absorbent layer on the first phosphor layer or under the second phosphor layer.