Granted Patent B2

US 12,641,910 · App. 18/393,210 · Granted May 26, 2026

Inventor: Hoon Kim (La Habra, CA)

H10F77/143H10F30/221H10F39/191H10F39/8057

Abstract

Claims (31)

1 . A photodetector comprising:

a metal layer to shield incident light and generate surface plasmon polaritons (SPPs);

an insulator;

a light absorbing layer to absorb the generated SPPs and allow charges excited by the SPPs and a localized electric field effect to tunnel through the insulator;

a dielectric formed at nanoholes in which at least a part of the metal layer is opened; and

a semiconductor layer to induce a photocurrent based on an electric field of the tunneled charges,

wherein the SPPs form localized electric field at an interface where the metal layer meets the dielectric,

wherein the localized electric field of the absorbed SPPs and tunneling of charges excited by photons of light induces the photocurrent, and

wherein the SPPs are absorbed into the semiconductor layer by using the light absorbing layer having a conduction band and a valence band in which an energy is split.

2 . The photodetector according to claim 1 , wherein the light absorbing layer includes a semiconductor having a conduction band and a valence band in which an energy level is split by applying uniaxial tensile stress.

3 . The photodetector according to claim 1 , wherein in the light absorbing layer, an energy level is split into a heavy hole and a light hole in the valence band.

4 . The photodetector according to claim 1 , wherein the photocurrent is generated by inducing the photocurrent through tunneling of charges caused by the SPPs.

5 . The photodetector according to claim 1 , wherein at least a part of the metal layer includes an opened nanohole, and the generated SPPs are absorbed into the light absorbing layer through the nanohole.

6 . The photodetector according to claim 5 , wherein the nanohole is formed of a material having a greater dielectric constant than air.

7 . The photodetector according to claim 5 , wherein the nanohole is formed of a material containing Si3N4, and the metal layer contains at least one of aluminum (Al), gold (Au), or silver (Ag).

8 . The photodetector according to claim 5 , wherein the metal layer is extended from a surface to the light absorbing layer and guides the generated SPPs to the light absorbing layer.

9 . The photodetector according to claim 1 , wherein a density of the localized electric field increases per unit area to increase the photocurrent as a size of the nanoholes decreases.

10 . An image sensor comprising:

a metal surface to shield incident light and generate surface plasmon polaritons (SPPs);

a metal nanohole array formed on the metal surface;

an insulator; and

a detector array formed at a position corresponding to the metal nanohole array, wherein the detector array comprises:

a light absorbing layer to absorb the generated SPPs and allow charges excited by the SPPs and a localized electric field effect to tunnel through the insulator;

a dielectric formed at the metal nanohole array in which at least a part of the metal layer is opened; and

a semiconductor layer to induce a photocurrent based on an electric field of the tunneled charges,

wherein the SPPs form localized electric field at an interface where the metal surface meets the dielectric,

wherein the metal surface is extended from a surface to the light absorbing layer and guides the generated SPPs to be transmitted to the light absorbing layer, and

wherein the detector array absorbs the SPPs into the semiconductor layer by using the light absorbing layer having a conduction band and a valence band in which an energy is split.

11 . The image sensor according to claim 10 , wherein the detector array generates the photocurrent by inducing the photocurrent through tunneling caused by the SPPs.

12 . The image sensor according to claim 10 , wherein the metal surface includes at least a part of an open nano-sized hole, and generate the localized electric field by the generated surface plasmon polariton at an interface of the nano-hole to tunnel photo-excited charges.

13 . The photodetector according to claim 10 , wherein a density of the localized electric field increases per unit area to increase the photocurrent as a size of the nanoholes decreases.

Assignments (1)

Continuity (4)

References Cited (54)