US-20260130010-A1 - LIGHT SOURCE USING PHOTONIC CRYSTAL STRUCTURE

Abstract

The inventive concept includes a substrate, a heterojunction structure including a first encapsulation layer, a graphene layer, and a second encapsulation layer sequentially stacked on the substrate, photonic crystal holes vertically penetrating the first encapsulation layer, the graphene layer, and the second encapsulation layer, and first and second electrodes respectively connected to both end portions of the heterojunction structure, The heterojunction structure includes buffer areas contacting the first and second electrodes, respectively, and emission areas between the buffer areas, The photonic crystal holes are provided in the emission area, and the width of the emission area is smaller than the widths of the buffer areas to provide a light source using a photonic crystal structure. In addition, a light source using the photonic crystal structure may be utilized as a photodetector.

Inventors

• Youngduck Kim

Assignees

• UNIVERSITY-INDUSTRY COOPERATION GROUP OF KYUNG HEE UNIVERSITY

Dates

Publication Date

20260507

Application Date

20251223

Priority Date

20191227

Claims (9)

1. 1 .- 11 . (canceled)
2. 12 . A light source comprising: a substrate; a heterojunction structure including a first encapsulation layer, a graphene layer, and a second encapsulation layer sequentially stacked on the substrate; photonic crystal holes vertically penetrating the first encapsulation layer, the graphene layer, and the second encapsulation layer; and first and second electrodes respectively connected to both end portions of the heterojunction structure, wherein the heterojunction structure comprises a first area in which the photonic crystal holes are not provided and a second area surrounding the first area, the second area in which the photonic crystal holes are regularly arranged.
3. 13 . The light source of claim 12 , wherein the heterojunction structure further comprises buffer areas between the second area and the first electrode and between the second area and the second electrode.
4. 14 . The light source of claim 12 , wherein a size of the photonic crystal holes decreases from the first area toward an edge of the second area.
5. 15 . The light source of claim 14 , wherein the first area is located in a center of an upper surface of the heterojunction structure.
6. 16 . The light source of claim 12 , further comprising a plurality of optical waveguides provided between the substrate and the heterojunction structure, wherein the optical waveguides are spaced apart from each other, wherein the first area vertically overlaps at least one of the optical waveguides.
7. 17 . The light source of claim 12 , wherein each of the first electrode and the second electrode is a source electrode or a drain electrode, wherein a pulse voltage or a DC bias voltage is applied to the first electrode and the second electrode.
8. 18 . The light source of claim 17 , wherein a degree of thermal expansion is adjusted according to an applied magnitude of the DC bias voltage, and a resonance frequency is controlled.
9. 19 . The light source of claim 12 , wherein a resonance frequency is controlled by adjusting a size and interval of the photonic crystal holes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a divisional of U.S. application Ser. No. 17/296,373, filed May 24, 2021, which claims priority to PCT International Application No. PCT/KR2020/017939 which has an International filing date of Dec. 9, 2020 under 35 U.S.C. § 371, which claims priority to Korean Patent Application No. 10-2019-0176539, filed on Dec. 27, 2019, the disclosures of each of which are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present disclosure relates to a light source using a photonic crystal structure, and more specifically, to a light source using a photonic crystal structure formed in a van der Waals heterojunction structure. BACKGROUND ART In a broad sense, a photonic crystal structure refers to a structure that affects the motion of a photon so that the optical properties of a material may be used. In addition, in a narrow sense, the photonic crystal structure may mean a structure that uses the optical properties of a material through a periodic optical nanostructure, and this periodic structure may be formed in 1D, 2D or 3D. The photonic crystal structure may be used in various technologies that need to confine or manipulate light, and various studies are being conducted to utilize the photonic crystal structure for optical modulation, light detection, or optical communication. In addition, unlike the conventional light emitting diode (LED) using the band structure characteristics of the material, the luminescence mechanism of a graphene light source is based on blackbody radiation by hot electrons. In general, blackbody radiation has a very wide spectrum of wavelengths from visible light to infrared light, so that its luminous efficiency is low and there is a limit to its application to optical communication technology. DISCLOSURE OF THE INVENTION Technical Problem The present disclosure is to provide a light source using a photonic crystal structure capable of controlling a spatial light emitting area and a light emitting wavelength. The problem to be solved by the present disclosure is not limited to the problems mentioned above, and other tasks that are not mentioned will be clearly understood by those of ordinary skill in the relevant technical field from the following description. Technical Solution In order to solve the above technical problems, a light source using the photonic crystal structure according to the embodiment of the inventive concept includes a substrate; a heterojunction structure including a first encapsulation layer, a graphene layer, and a second encapsulation layer sequentially stacked on the substrate; photonic crystal holes vertically penetrating the first encapsulation layer, the graphene layer, and the second encapsulation layer; and first and second electrodes respectively connected to both end portions of the heterojunction structure, wherein the heterojunction structure comprises buffer areas contacting the first and second electrodes, respectively, and emission areas between the buffer areas, wherein the photonic crystal holes are provided in the emission area, wherein a width of the emission area is smaller than widths of the buffer areas. In addition, a light source using the photonic crystal structure according to the embodiment of the inventive concept includes: a substrate; a heterojunction structure including a first encapsulation layer, a graphene layer, and a second encapsulation layer sequentially stacked on the substrate; photonic crystal holes vertically penetrating the first encapsulation layer, the graphene layer, and the second encapsulation layer; and first and second electrodes respectively connected to both end portions of the heterojunction structure, wherein the heterojunction structure comprises a first area in which the photonic crystal holes are not provided and a second area surrounding the first area, the second area in which the photonic crystal holes are regularly arranged. Advantageous Effects The light source using the photonic crystal structure according to the embodiment of the inventive concept may cause a strong light-material interaction at the heterojunction interface using the photonic crystal structure formed in the van der Waals heterojunction structure, so that a high quality value (Q-factor) may be maintained. In addition, the light source using the photonic crystal structure according to the embodiment of the inventive concept may adjust the spatial light emitting area and the light emission wavelength through the modification of the photonic crystal structure, so that energy efficiency may be further increased. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a structure of a light source using a photonic crystal structure according to an embodiment of the inventive concept. FIGS. 2 and 3 are cross-sectional views illustrating a structure of a light source using a photonic crystal structure according to an embodiment of the inventive concept, an