Photodetector, detection device, and fabricating method thereof

Abstract

A photodetector includes a semiconductor layer, a metal layer, a first electrode, and a second electrode. The semiconductor layer has a composite structure array composed of multiple composite structures. At least a portion of the surface of the metal layer forms a Schottky contact with the surface of the composite structure array, and the first electrode is in contact with the upper surface of the metal layer. The second electrode forms an ohmic contact with the lower surface of the semiconductor layer. Each composite structure includes a resonant cavity in which incident light resonates, and an intermediate core structure located within the resonant cavity for collecting and capturing strong resonant energy.

Claims

1. A photodetector element, comprising: a semiconductor layer having a composite structure array composed of a plurality of structures; a metal layer having at least a portion of its surface forming a Schottky contact with the surface of the composite structure array; a first electrode in contact with the upper surface of the metal layer; and a second electrode in an ohmic contact with the lower surface of the semiconductor layer; wherein, Each of these composite structures includes a resonant cavity in which an incident light resonates, and an intermediate core structure located within the resonant cavity for collecting and capturing resonant energy.

2. The photodetector element of claim 1, wherein the resonant cavity is shaped as an inverted pyramid, an inverted trapezoid, a cuboid, or a cup.

3. The photodetector element of request item 1 or 2, wherein the shape of the intermediate core structure is an upright pyramid, cylinder, rectangular prism, trapezoid, or cone.

4. The photodetector element of claim 1, wherein the photodetector element is used to detect the incident light with a wavelength greater than 1.1 micrometers (μm).

5. The photodetector element of claim 1, wherein the responsivity of the photodetector element for incident light of wavelength 3.46 μm is equal to or greater than 0.557 V / W.

6. The photodetector element of claim 1, wherein the first electrode is grid-shaped.

7. The photodetector element of claim 1, wherein the first electrode is mesh-like.

8. The photodetector element of claim 1, wherein the metal layer system is conformally deposited on the surface of the plurality of composite structures.

9. The photodetector element of claim 1, wherein the thickness of the metal layer is approximately 10 nm.

10. A method for manufacturing a photodetector, comprising: providing a semiconductor substrate; depositing a shielding layer on an upper surface of the semiconductor substrate; depositing a photoresist layer on the upper surface of the semiconductor substrate above the shielding layer; exposing and developing the semiconductor substrate and the photoresist layer using a photomask as a mask to obtain a patterned photoresist layer, the photomask comprising an array of light-shielding patterns, each light-shielding pattern in the array comprising a light-transmitting core portion, or each light-shielding pattern comprising a peripheral pattern and a core pattern located within the peripheral pattern; etching the shielding layer and the patterned photoresist layer to obtain a patterned shielding layer; etching the semiconductor substrate to form a composite structure array on the surface of the semiconductor substrate, wherein the composite structure array comprises a plurality of composite structures, each composite structure comprising a resonant cavity for resonating an incident light therein and an intermediate core structure located within the resonant cavity for collecting and capturing resonant energy; and depositing a metal layer on the surface of the plurality of composite structures. A first electrode is deposited on the metal layer; and a second electrode is deposited on the lower surface of the semiconductor substrate.

11. The method for manufacturing the light-detecting element as claimed in claim 10, wherein the light-shielding pattern is a square shape.

12. The method of manufacturing the photodetector element of claim 10, wherein the metal layers are conformally formed on the surface of the plurality of composite structures.

13. A detection device for detecting a light source, the detection device comprising an array of photodetectors, the array of photodetectors comprising one or more photodetectors as described in any one of claims 1 to 9.

14. The detection device as claimed in claim 13, wherein the detection device is a thermal imaging device.

15. The detection device of claim 13, wherein the detection device is used to detect one or more test gases, the detection device further includes a gas chamber in which the one or more test gases are disposed, and the light source passes through the one or more test gases and is received by the photodetector array and converted into an electrical signal.

16. The detection device of claim 15, wherein the light source is a light source with wavelengths covering near-infrared (NIR) to mid-wave infrared (MWIR), the detection device further comprising one or more reflective / lenses and a filter array, wherein the light source passes through the one or more reflective / lenses disposed in the air chamber, and then through the filter array, and is received by the light detection element array and converted into an electrical signal.

17. The detection device of claim 15, wherein the light source is a light source with wavelengths covering near-infrared (NIR) to mid-wave infrared (MWIR), and the detection device further includes a beam splitter, wherein the light source, after passing through the beam splitter disposed in the air chamber, is received by the light detection element array and converted into an electrical signal.

18. The detection apparatus of claim 15, wherein the light source comprises a plurality of narrowband light sources to emit monochromatic light beams of different wavelengths, the monochromatic light beams passing through the one or more gases to be measured and then received by the photodetector array and converted into electrical signals.

19. The detection device of claim 18, wherein the gas chamber comprises a plurality of gas channels, the plurality of gas channels being interconnected but not interfering with each other in terms of optical path, each gas channel containing one or more gases to be measured, and the monochromatic light beams passing through one of the gas channels being received and converted into electrical signals by one or more corresponding optical detection elements in the optical detection element array.

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