CN114267749B

CN114267749B - Photoconductive semiconductor switch based on graphene film

Info

Publication number: CN114267749B
Application number: CN202111586363.4A
Authority: CN
Inventors: 李伟; 李佳峻
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2023-05-09
Anticipated expiration: 2041-12-22
Also published as: CN114267749A

Abstract

The invention discloses a photoconductive semiconductor switch based on a graphene film, belongs to the technical field of photoconductive semiconductor switches, and aims to overcome the defect that plasma filament current is caused by high surface current density of a traditional switch, so that the switch is burnt, and the change into bulk current is convenient to bear higher voltage. The semiconductor substrate comprises a semiconductor substrate with a grid structure, a first transition layer, a first graphene film and a cathode which are sequentially arranged on the semiconductor substrate, and a second transition layer, a second graphene film and an anode which are sequentially arranged on the semiconductor substrate. The invention is used for disturbing and damaging electronic equipment such as unmanned aerial vehicles, missiles and the like.

Description

Photoconductive semiconductor switch based on graphene film

Technical Field

A photoconductive grating type semiconductor switch based on a graphene film is used for disturbing and damaging electronic equipment such as unmanned aerial vehicles, missiles and the like, and belongs to the technical field of photoconductive semiconductor switches.

Background

The electrode of the photoconductive semiconductor switch in the prior art is in ohmic contact with the semiconductor material through the transition metal, so that the following technical problems exist:

1. the contact resistance between the electrode of the photoconductive semiconductor switch in the prior art and the semiconductor material through the transition metal is larger, so that the electrode has the defects of heat generation and poor heat conduction;

2. in the prior art, the photoconductive semiconductor switch surface discharges, plasma wire discharge is formed on the surface of the switch to burn the switch, so that the problems of low voltage, low repetition frequency, long pulse rising edge time, short service life and the like are caused.

Disclosure of Invention

Aiming at the problems of the researches, the invention aims to provide a light guide grid type semiconductor switch based on a graphene film, which solves the problems of low heat dissipation, low voltage resistance, low heavy frequency, narrow bandwidth, short service life and the like of a lighting burning switch caused by overlarge current density on the surface of the semiconductor switch in the prior art.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the utility model provides a photoconductive semiconductor switch based on graphite alkene membrane, includes the semiconductor substrate of bars type structure, sets gradually first transition layer, first graphite alkene membrane and the negative pole on the semiconductor substrate, sets gradually second transition layer, second graphite alkene membrane and positive pole on the semiconductor substrate.

Further, the first transition layer, the first graphene film and the cathode are sequentially arranged on the upper surface of the semiconductor substrate;

the second transition layer, the second graphene film and the anode are sequentially arranged on the upper surface or the lower surface of the semiconductor substrate.

Further, the semiconductor substrate is made of gallium arsenide or silicon carbide with a purity of 99.999% or more, and periodic grooves, namely the grid structure 8, are etched.

Further, the first transition layer and the second transition layer are made of metal materials.

Further, the first and second transition layers are comprised of one of platinum or palladium.

Further, the first graphene film and the second graphene film are single-layer graphene, and the thickness of the first graphene film and the second graphene film is in the order of micrometers.

Further, the cathode and anode are prepared from copper gold plating.

Further, on the laser irradiation side, periodic grooves are etched on the semiconductor substrate, wherein the width of each groove is 1mm-3mm, the length of each groove is 10mm-20mm, and the depth of each groove is 3mm.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the grid type photoconductive semiconductor switch, a layer of graphene film is added below the front electrode and the back electrode, namely the cathode and the anode, so that the performance is greatly improved, namely the ohmic contact, voltage resistance and heat dissipation characteristics of the electrodes, the transition layer and GaAs/SiC are greatly improved, the switching speed is higher, the voltage resistance is higher, the bandwidth of electromagnetic waves generated by photoconductive switching-on of the semiconductor switch is expanded, the bearable power density is higher, the voltage resistance can be more than 20KV, the service life can be more than ten thousands of times, and the voltage resistance of the photoconductive switch in the prior art is about 10KV, and the service life is short by thousands of times; the electric field obtained by adopting the front and back electrodes on the semiconductor substrate is not only on the surface, so that the damage of a switch caused by easy ignition of the electrodes is avoided, but also the three-dimensional grid structure enables generated photocurrent to pass through a fixed channel (current channel), namely, the photocurrent becomes bulk current, the whole volume of the semiconductor substrate is utilized, the current density is reduced, or the withstand voltage is improved by an order of magnitude under the same current density;

2. the high-power ultra-wideband electromagnetic wave generated by the graphene film photoconductive semiconductor switch covers the working wave bands of most electronic equipment (such as unmanned aerial vehicles, missiles and the like) because the bandwidth is wider, so that the high-power ultra-wideband electromagnetic wave can be coupled into the circuits of the electronic equipment from front doors and rear doors (holes, gaps and the like) to interfere and damage the electronic elements, and the high-power ultra-wideband electromagnetic pulse radar cannot be hidden by the conventional stealth aircraft due to the high-power ultra-wideband generated by the photoconductive semiconductor switch;

3. the light guide semiconductor switch based on the graphene film can generate the advantages of high peak power, narrow pulse, low triggering jitter and higher high-frequency electric pulse, and lays a solid foundation for developing light control array active ultra-wideband radar integrating short-range electromagnetic interference and medium-and-long-range target detection and electronic targets such as an interference damage unmanned aerial vehicle, a missile and the like, and has the advantages of small volume, light weight, low interception probability, high resolution and strong electromagnetic interference resistance and stealth resistance;

4. the photoconductive switch has the advantages of high power density, high response speed, low triggering jitter, strong electromagnetic interference resistance, small volume, easy integration and the like, and has wide application prospect in the fields of high-current ignition devices, weapons rejection and high-power microwave systems, THz technology, impulse radars, electromagnetic interference and attack systems and the like.

Drawings

Fig. 1 is a schematic view of a layered structure in which an anode and a cathode are disposed on opposite sides, wherein 1 is a semiconductor substrate, 2 is a first transition layer, 3 is a first graphene film, 4 is a cathode, 5 is a second transition layer, 6 is a second graphene film, and 7 is an anode;

FIG. 2 is a top view of the anode and cathode of the present invention disposed on the same side;

FIG. 3 is a cross-sectional view of FIG. 2 in a side view;

Detailed Description

The invention will be further described with reference to the drawings and detailed description.

According to the invention, a different-surface electrode structure is adopted, as shown in fig. 1, a grid-shaped structure is etched on a semiconductor substrate, a layer of graphene film is added under a switch electrode, and laser spots matched with the grid-shaped structure are adopted to irradiate on the grid-shaped structure in a strip shape, so that a special current channel is formed, the phenomenon that surface plasma is formed into filament current to destroy a switch is avoided, the current density of the surface is reduced, and a bulk current mode is formed, namely, the plasma filament current caused by high surface current density of the traditional switch is overcome, so that the switch is burnt, and the bulk current is changed into a bulk current so as to be convenient to bear higher voltage, as shown in fig. 2 and 3.

The concrete structure is as follows:

the light guide semiconductor switch based on the graphene film comprises a semiconductor substrate 1 with a grid structure, a first transition layer 2, a first graphene film 3 and a cathode 4 which are sequentially arranged on the semiconductor substrate 1, and a second transition layer 5, a second graphene film 6 and an anode 7 which are sequentially arranged on the semiconductor substrate 1. The first transition layer 2, the first graphene film 3 and the cathode 4 are sequentially arranged on the upper surface of the semiconductor substrate 1; the second transition layer 5, the second graphene film 6 and the anode 7 are sequentially disposed on the upper surface or the lower surface of the semiconductor substrate 1, that is, the first transition layer 2, the first graphene film 3 and the cathode 4 may be disposed on the same side as the second transition layer 5, the second graphene film 6 and the anode 7, or may be disposed on the opposite side.

The semiconductor substrate 1 is made of gallium arsenide or silicon carbide with a purity of 99.999% or more, and periodic grooves, namely the grid structure 8, are etched.

The first transition layer 2 and the second transition layer 5 are made of metal, and the first transition layer 2 and the second transition layer 5 are made of one of platinum or palladium, but may be other metals.

The first graphene film 3 and the second graphene film 6 are single-layer graphene, and the thickness is in the order of μm.

The cathode 4 and the anode 7 are made of copper gold plating.

The semiconductor substrate 1 is etched with periodic grooves having a width of 1mm to 3mm, e.g., 2mm, a length of 10mm to 20mm, e.g., 11mm, 12mm or 13mm, and a depth of about 3mm. In practice, the triggered laser spot (stripe laser as shown in fig. 2) is 1mm-2mm wide and 10mm-20mm long, matching the periodic grooves, thus forming a current path as shown in fig. 3.

Working principle: bar laser pulse triggering corresponding gridThe semiconductor with the structure is biased under the condition of an electric field, the GaAs/SiC of the photoconductive material (semiconductor substrate) absorbs photons to generate electron hole pairs, and a large-amplitude electric pulse is output in a corresponding current channel, so that a photoconductive switch with higher power can be obtained under the grid structure. And due to the addition of the graphene film, the heat dissipation strip shape and the electron mobility of the switch are improved, the steeper the rising edge of the pulse can be generated, and the wider the frequency band of the ultra-wideband electromagnetic pulse can be generated. Graphene has a carrier mobility of about 15000cm at room temperature ² And the graphene film is added, so that ohmic contact, voltage resistance and heat dissipation characteristics of an electrode, a transition layer and GaAs/SiC are greatly improved, and the graphene/GaAs/SiC composite solar cell has the advantages of higher switching speed, higher voltage resistance and higher bearable power density.

In conclusion, the strip-shaped light spots are matched with the grid structure and the graphene film, so that the heat dissipation characteristic and the performance of the switch are further improved. The voltage withstanding, power, bandwidth and repetition frequency of the pulse power device formed by the method are greatly improved. The problems of low withstand voltage, short service life, low repetition frequency and the like of the photoconductive semiconductor switch are solved, and the photoconductive semiconductor switch is used as a core device of an jammer, a radar and the like to directly influence the reachable power level and the fight distance.

The above is merely representative examples of numerous specific applications of the present invention and should not be construed as limiting the scope of the invention in any way. All technical schemes formed by adopting transformation or equivalent substitution fall within the protection scope of the invention.

Claims

1. A photoconductive semiconductor switch based on graphene film, characterized in that: the semiconductor device comprises a semiconductor substrate (1) with a grid structure, a first transition layer (2), a first graphene film (3) and a cathode (4) which are sequentially arranged on the semiconductor substrate (1), and a second transition layer (5), a second graphene film (6) and an anode (7) which are sequentially arranged on the semiconductor substrate (1); on the laser irradiation side, periodic grooves are etched on the semiconductor substrate to form a grid structure.

2. The graphene-film-based photoconductive semiconductor switch of claim 1, wherein: the first transition layer (2), the first graphene film (3) and the cathode (4) are sequentially arranged on the upper surface of the semiconductor substrate (1);

the second transition layer (5), the second graphene film (6) and the anode (7) are sequentially arranged on the upper surface or the lower surface of the semiconductor substrate (1).

3. The graphene-film-based photoconductive semiconductor switch of claim 2, wherein: the semiconductor substrate (1) is prepared from one of gallium arsenide or silicon carbide with the purity of more than 99.999 percent.

4. A graphene film-based photoconductive semiconductor switch as in claim 3, wherein: the first transition layer (2) and the second transition layer (5) are made of metal materials.

5. The graphene-film-based photoconductive semiconductor switch of claim 4, wherein: the first transition layer (2) and the second transition layer (5) are made of one of platinum or palladium.

6. A graphene film-based photoconductive semiconductor switch according to any one of claims 1-5, wherein: the first graphene film (3) and the second graphene film (6) are single-layer graphene, and the thickness of the first graphene film and the second graphene film is in the order of mu m.

7. The graphene-film-based photoconductive semiconductor switch of claim 6, wherein: the cathode (4) and the anode (7) are prepared by copper gold plating.

8. The graphene-film-based photoconductive semiconductor switch of claim 7, wherein: the width of the groove is 1mm-3mm, the length is 10mm-20mm, and the depth is 3mm.