Beam steering device including P-N junction layer
A beam steering device is provided including a p-n junction layer disposed on a reflective electrode layer, wherein a refractive index of the p-n junction layer is variable according to a voltage applied to the reflective electrode layer; a nanoantenna layer including a plurality of components disposed on the p-n junction layer; and a common electrode electrically connected to each of the plurality of components of the nanoantenna. The p-n junction layer may include a p-doped layer and an n-doped layer.
1. A beam steering device, the device comprising:
a reflective electrode layer;
a p-n junction layer disposed on the reflective electrode layer, wherein a refractive index of the p-n junction layer is variable according to a voltage applied to the reflective electrode layer;
a nanoantenna layer, disposed on the p-n junction layer, wherein the nanoantenna layer comprises a plurality of components; and
a common electrode electrically connected to each of the plurality of components of the nanoantenna layer,
wherein the p-n junction layer comprises a p-doped layer and an n-doped layer.
2. The device of claim 1 , wherein the p-doped layer comprises one of a p-type oxide semiconductor and p-silicon.
3. The device of claim 2 , wherein the p-doped layer comprises at least one of nanocrystalline cuprous aluminate delafossite (CuAlO 2 ), nickel oxide (NiO), and copper oxide (CuO).
4. The device of claim 1 , wherein the n-doped layer comprises at least one of Indium-Tin-Oxide (ITO), Indium-Zinc-Oxide (IZO), Ga—In—Zn-Oxide (GIZO), Al—Zn-Oxide (AZO), Ga—Zn-Oxide (GZO), and zinc oxide (ZnO).
5. The device of claim 1 , wherein the reflective electrode layer comprises a plurality of reflective electrodes separated from each other, wherein each of the plurality of reflective electrodes corresponds to a respective one of a plurality of pixel areas.
6. The device of claim 5 , further comprising a driving circuit comprising a plurality of drivers, wherein each of the plurality of drivers applies a driving voltage to a corresponding one of the plurality of reflective electrodes.
7. The device of claim 6 , wherein each of the plurality of reflective electrodes and each of the plurality of components of the nanoantenna layer comprise at least one of silver (Ag), gold (Au), aluminum (Al), an alloy comprising Ag, Au, or Al, titanium nitride (TiN), and tantalum nitride (TaN).
8. The device of claim 1 , wherein the common electrode is a wiring connected to each of the plurality of components.
9. The device of claim 1 , wherein the common electrode is a transparent electrode layer disposed between the p-n junction layer and the nanoantenna layer.
10. The device of claim 1 , further comprising an intrinsic layer disposed between the p-doped layer and the n-doped layer, wherein a doping density of the intrinsic layer is lower than a doping density of the p-doped layer and a doping density of the n-doped layer.
11. The device of claim 1 , further comprising an insulating layer disposed between the p-n junction layer and the nanoantenna layer.
12. The device of claim 11 , wherein the insulating layer has a thickness of about 10 nm to about 20 nm.
13. The device of claim 11 , wherein the common electrode is a transparent electrode layer disposed between the p-n junction layer and the insulating layer or disposed between the insulating layer and the nanoantenna layer.
14. The device of claim 1 , wherein each of the plurality of components of the nanoantenna layer has one of a circular shape, an elliptical shape, and a polygonal shape when viewed from a plan view.
15. The device of claim 1 , wherein each of the plurality of components of the nanoantenna layer has a length shorter than a wavelength of a beam irradiated on the nanoantenna layer, and wherein a gap between adjacent ones of the plurality of components of the nanoantenna layer is shorter than the wavelength.
16. The device of claim 1 , wherein the p-doped layer is disposed directly on the reflective electrode layer.