CN114649428A - Novel two-dimensional/three-dimensional heterogeneous high-speed photoelectric detector and preparation method thereof - Google Patents

Abstract

A novel two-dimensional/three-dimensional heterogeneous high-speed photodetector and a preparation method thereof, the high-speed photodetector comprises: a substrate, the material is a three-dimensional material silicon; a dielectric layer is formed on the surface of the substrate; an active layer, The material is a two-dimensional material germanium selenide, which is arranged on the adjacent area of the substrate surface and the surface of the dielectric layer; the source electrode is arranged on the adjacent area of the active layer and the dielectric layer; the drain electrode is arranged on the active layer. on the adjacent area of the layer and the substrate. The detector combines germanium selenide with silicon, realizes the light detection range from the visible light region to the near-infrared region, and improves the response time of the photodetector, and has the potential to become a wide bandwidth photodetector.

Description

Novel two-dimensional/three-dimensional heterogenous high-speed photodetector and its preparation method

technical field

The present disclosure relates to the technical field of photoelectric detection, and in particular, to a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector.

Background technique

Two-dimensional semiconductors, with their tunable energy bands, good flexibility, integration compatibility, and strong coupling with light, play an increasingly important role in modern nanoelectronics and optoelectronics. To date, a large number of hybrid 1D/2D, 2D/2D and 2D/3D heterogenous photodetectors have been successfully fabricated, among which 2D/3D heterogenous photodetectors have unique The advantages of low dark current, high signal-to-noise ratio, low energy consumption, and fast response.

On the one hand, 2D/3D heterojunctions have stronger light absorption capacity than 1D (2D)/2D heterojunctions, laying a solid foundation for the generation of photocarriers. On the other hand, 2D/3D heterojunction photodetectors can easily transfer and integrate 2D materials onto well-established commercial substrates such as silicon and graphene. When light is incident on the 2D/3D heterojunction photodetector, the photo-excited carriers cause the electrical conductivity of the detector to change, thereby converting the optical signal into an electrical signal. Since there are no dangling bonds on the surface of the two-dimensional material, it can be combined with the bulk material with lattice mismatch. Secondly, the thickness of the two-dimensional material is very thin, and the diffusion time of carriers in the two-dimensional material is reduced, thereby effectively improving the photodetector. response speed. 2D/3D heterojunction photodetectors can play an important role in the field of high-speed detectors.

SUMMARY OF THE INVENTION

The invention provides a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector and a preparation method thereof.

One aspect of the present disclosure provides a novel two-dimensional/three-dimensional heterogenous high-speed photodetector, comprising: a substrate, the material being a three-dimensional material silicon; a dielectric layer formed on the surface of the substrate; an active layer, The material is a two-dimensional material germanium selenide, which is arranged on the adjacent area of the substrate surface and the surface of the dielectric layer; the source electrode is arranged on the adjacent area of the active layer and the dielectric layer. ; Drain electrode, arranged on the adjacent area of the active layer and the substrate.

Optionally, the material of the source electrode and the drain electrode is gold.

Optionally, the material of the dielectric layer is SU-8 photoresist.

Optionally, the detection band of the high-speed photodetector includes a visible light band and a near-infrared band.

Another aspect of the present disclosure provides a method for preparing a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector, comprising: spin-coating a mask on a substrate, the substrate material being a three-dimensional material silicon; Photolithography the layout of the dielectric layer on the mask to form a dielectric layer; clean the mask; transfer the pre-prepared active layer to the adjacent area of the substrate and the surface of the dielectric layer, the active layer is The source layer material is a two-dimensional material germanium selenide; a source electrode is deposited and etched between the active layer and the dielectric layer, and a source electrode is deposited and etched between the active layer and the substrate Drain electrode; encapsulate the overall structure formed by the substrate, the dielectric layer, the active layer, the source electrode and the drain electrode to obtain a high light speed photodetector.

Optionally, the material of the dielectric layer is SU-8 photoresist, and the cleaning of the mask includes: cleaning the remaining photoresist on the mask with propylene glycol methyl ether acetate.

Optionally, the transferring the pre-prepared active layer to the adjacent area of the substrate and the surface of the dielectric layer comprises: peeling off the pre-prepared active layer with a dimethylsiloxane transfer tape through a two-dimensional material transfer platform. The active layer is prepared, and the active layer is transferred onto the substrate and the adjacent area of the surface of the dielectric layer.

Optionally, the depositing and etching the source electrode between the active layer and the dielectric layer, and the depositing and etching the drain electrode between the active layer and the substrate include: depositing Said source electrode and drain electrode fabrication material; spin-coating electrode mask on said source electrode and drain electrode fabrication material; photolithography electrode layout on said electrode mask, etching said source electrode and drain electrode; cleaning the electrode mask.

Optionally, the electrode mask material is polymethyl methacrylate, and the cleaning of the electrode mask includes: sequentially cleaning the electrode mask with acetone, ethanol and deionized water.

The above-mentioned at least one technical solution adopted in the embodiments of the present disclosure can achieve the following beneficial effects:

A novel two-dimensional/three-dimensional heterogenous high-speed photodetector provided by an embodiment of the present disclosure, germanium selenide (GeSe) as a P-type semiconductor, forms a heterojunction with an N-type semiconductor silicon (Si) and forms a space Charge region; GeSe, as a two-dimensional active layer, has a small thickness, and the diffusion time of carriers in this layer is significantly reduced, thereby improving the response speed of the photodetector; Si and GeSe can be applied to spectral detection in the visible region to the near-infrared region .

Description of drawings

For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 schematically shows a schematic plan view of a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector provided by an embodiment of the present disclosure;

FIG. 2 schematically shows a schematic cross-sectional view of a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector provided by an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an energy band structure of a two-dimensional/three-dimensional heterogeneous high-speed photodetector according to an embodiment of the present disclosure;

Description of reference numbers:

11-silicon wafer substrate; 12-source electrode; 13-drain electrode; 14-dielectric layer; 15-germanium selenide active layer.

Detailed ways

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that these descriptions are exemplary only, and are not intended to limit the scope of the present disclosure. In the following detailed description, for convenience of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent, however, that one or more embodiments may be practiced without these specific details. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present disclosure. The terms "comprising", "comprising" and the like as used herein indicate the presence of stated features, steps, operations and/or components, but do not preclude the presence or addition of one or more other features, steps, operations or components.

All terms (including technical and scientific terms) used herein have the meaning as commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly rigid manner.

As shown in FIG. 1 and FIG. 2 , an embodiment of the present disclosure provides a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector, including: a substrate, a dielectric layer, an active layer, a source electrode, and a drain electrode. Wherein, the base material is a three-dimensional material silicon; a dielectric layer is formed on the surface of the base; the active layer material is a two-dimensional material germanium selenide, which is arranged in the adjacent area between the surface of the base and the surface of the dielectric layer the source electrode is arranged on the adjacent area of the active layer and the dielectric layer; the drain electrode is arranged on the adjacent area of the active layer and the substrate.

Optionally, the material of the source electrode and the drain electrode is gold.

Optionally, the material of the dielectric layer is SU-8 photoresist.

GeSe is a two-dimensional P-type semiconductor material with good flexibility and high detection rate; Si is a traditional three-dimensional N-type semiconductor material. The germanium selenide (GeSe) as the active layer is stacked in layers along the a-axis, the surface of the nanosheet is b-c plane, and belongs to the orthorhombic structure with space group Pnma; the light of the semiconductor material germanium selenide (GeSe) The response range includes the entire visible light and near-infrared light domains. After combining with silicon (Si), the detection bands of the high-speed photodetector include the visible light band and the near-infrared band.

FIG. 3 shows a schematic diagram of an energy band structure of a two-dimensional/three-dimensional heterogenous high-speed photodetector provided by an embodiment of the present disclosure. The novel two-dimensional/three-dimensional heterogeneous high-speed photodetector provided in this embodiment combines GeSe and Si to form a heterojunction and form a space charge region inside. After light is irradiated on the PN junction, photogenerated carriers are generated. Under the action of an external bias voltage, the electrons and holes move to the source electrode and the drain electrode respectively to form a current, which converts the optical signal into an electrical signal. The response time of the detector includes the drift time of carriers in the space charge region and the diffusion time in the germanium selenide and silicon layers. The carrier diffusion time is significantly reduced, thereby improving the response speed of the GeSe/Si heteroheteromeric photodetector.

Another embodiment of the present disclosure provides a method for fabricating a novel two-dimensional/three-dimensional heterogeneous high-speed photodetector, including operations S1-S6.

In operation S1, a mask is spin-coated on a substrate, and the substrate material is silicon, a three-dimensional material.

In operation S2, the dielectric layer is patterned on the mask to form a dielectric layer.

In this embodiment, the mask material for constructing the dielectric layer can be selected from SU-8 photoresist.

In operation S3, the mask is cleaned.

In this embodiment, propylene glycol methyl ether acetate can be used to clean the remaining photoresist on the mask.

In operation S4, the pre-prepared active layer is transferred to the adjacent regions of the substrate and the surface of the dielectric layer, and the active layer material is a two-dimensional material germanium selenide.

In this embodiment, the pre-prepared active layer can be peeled off with a dimethylsiloxane transfer tape through a two-dimensional material transfer platform, and the active layer can be transferred to the phase between the substrate and the surface of the dielectric layer. on the adjacent area.

In operation S5, a source electrode is deposited and etched between the active layer and the dielectric layer, and a drain electrode is deposited and etched between the active layer and the substrate.

Operation S5 specifically includes S501 to S504.

In operation S501, the source electrode and drain electrode fabrication materials are deposited.

In operation S502, an electrode mask is spin-coated on the source electrode and the drain electrode fabrication material.

In operation S503, an electrode layout is etched on the electrode mask, and the source electrode and the drain electrode are etched.

In operation S504, the electrode mask is cleaned.

Optionally, acetone, ethanol and deionized water can be used to clean the electrode mask in sequence.

In operation S6, the overall structure formed by the substrate, the dielectric layer, the active layer, the source electrode, and the drain electrode is packaged to obtain a high-light-speed photodetector.

Those skilled in the art will appreciate that various combinations and/or combinations of features recited in various embodiments and/or claims of the present disclosure are possible, even if such combinations or combinations are not expressly recited in the present disclosure. In particular, various combinations and/or combinations of the features recited in the various embodiments of the present disclosure and/or in the claims may be made without departing from the spirit and teachings of the present disclosure. All such combinations and/or combinations fall within the scope of this disclosure.

Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, those skilled in the art will appreciate that, without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents, Various changes in form and detail have been made in the present disclosure. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments, but should be determined not only by the appended claims, but also by their equivalents.

Claims (9)

1. A novel two-dimensional/three-dimensional heterogeneous high-speed photoelectric detector is characterized by comprising:

the substrate is made of three-dimensional material silicon;

a dielectric layer formed on the substrate surface;

the active layer is made of two-dimensional material germanium selenide and is arranged on the adjacent area of the surface of the substrate and the surface of the dielectric layer;

a source electrode disposed on adjacent regions of the active layer and the dielectric layer;

and the drain electrode is arranged on the adjacent area of the active layer and the substrate.

2. The high-speed photodetector of claim 1, wherein the material of said source and drain electrodes is gold.

3. A high speed photodetector as claimed in claim 1 wherein the material of the dielectric layer is SU-8 photoresist.

4. The high-speed photodetector of claim 1, wherein the detection bands of the high-speed photodetector comprise visible and near infrared bands.

5. A preparation method of a novel two-dimensional/three-dimensional heterogeneous high-speed photoelectric detector is characterized by comprising the following steps:

spin-coating a mask on a substrate, wherein the substrate is made of three-dimensional material silicon;

etching a dielectric layer layout on the mask to form a dielectric layer;

cleaning the mask;

transferring a pre-prepared active layer onto the substrate and an adjacent area on the surface of the dielectric layer, wherein the active layer is made of a two-dimensional material of germanium selenide;

depositing and etching a source electrode between the active layer and the dielectric layer, and depositing and etching a drain electrode between the active layer and the substrate;

and packaging the integral structure formed by the substrate, the dielectric layer, the active layer, the source electrode and the drain electrode to obtain the high-light-speed photoelectric detector.

6. The method of claim 5, wherein the dielectric layer is made of SU-8 photoresist, and wherein cleaning the mask comprises:

and cleaning the residual photoresist on the mask by using propylene glycol methyl ether acetate.

7. The method of claim 5, wherein transferring the pre-fabricated active layer onto the substrate and onto the adjacent region of the surface of the dielectric layer comprises:

and peeling off the pre-prepared active layer by using a dimethyl siloxane transfer adhesive tape through a two-dimensional material transfer platform, and transferring the active layer onto the adjacent areas of the surfaces of the substrate and the dielectric layer.

8. The method of claim 5, wherein depositing and etching a source electrode between the active layer and the dielectric layer, and depositing and etching a drain electrode between the active layer and the substrate comprises:

depositing the manufacturing materials of the source electrode and the drain electrode;

spin-coating an electrode mask on the source electrode and drain electrode manufacturing materials;

etching an electrode layout on the electrode mask to etch the source electrode and the drain electrode;

and cleaning the electrode mask.

9. The method of claim 8, wherein the electrode mask material is polymethylmethacrylate, and wherein cleaning the electrode mask comprises:

and cleaning the electrode mask by adopting acetone, ethanol and deionized water in sequence.

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