CN114267749A

CN114267749A - Photoconductive semiconductor switch based on graphene film

Info

Publication number: CN114267749A
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: 2022-04-01
Anticipated expiration: 2041-12-22
Also published as: CN114267749B

Abstract

The invention discloses a graphene film-based photoconductive semiconductor switch, belongs to the technical field of photoconductive semiconductor switches, and overcomes the defect that plasma filamentary current is caused by high surface current density of a traditional switch, so that the switch is burnt and becomes bulk current which is convenient to bear higher voltage. The graphene oxide thin film solar cell comprises a semiconductor substrate with a grid-type 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 interfering and damaging electronic equipment such as unmanned aerial vehicles, missiles and the like.

Description

Photoconductive semiconductor switch based on graphene film

Technical Field

A graphene film-based optical waveguide gate type semiconductor switch is used for interfering and damaging electronic equipment such as unmanned aerial vehicles and missiles and belongs to the technical field of optical waveguide semiconductor switches.

Background

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

1. in the prior art, the contact resistance of an electrode of a photoconductive semiconductor switch and a semiconductor material is large through transition metal, so that the electrode has poor heating and heat conduction;

2. the problems of low voltage, low repetition frequency, long pulse rising edge time, short service life and the like caused by plasma filament discharge formed on the surface of a switch by the switch surface discharge of a photoconductive semiconductor in the prior art and the burning of the switch are solved.

Disclosure of Invention

In view of the above-mentioned problems, an object of the present invention is to provide a graphene film-based optical waveguide gate type semiconductor switch, which solves the problems of the prior art, such as the switch being burnt by firing due to excessive current density on the surface of the semiconductor switch, poor heat dissipation, low withstand voltage, low repetition frequency, narrow bandwidth, and short service life.

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

a photoconductive semiconductor switch based on a graphene film comprises a semiconductor substrate with a grid-type structure, a first transition layer, the 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.

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 prepared from one of gallium arsenide or silicon carbide with the purity of more than 99.999%, and a periodic groove, namely a gate structure 8, is etched.

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

Further, the first transition layer and the second transition layer are made of one of platinum or palladium.

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

Further, the cathode and the anode are made of copper plated with gold.

Furthermore, on the laser irradiation side, a periodic groove is etched on the semiconductor substrate, the width of the groove is 1mm-3mm, the length of the groove is 10mm-20mm, and the depth of the groove is 3 mm.

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

the invention adds a layer of graphene film under the positive and negative electrodes, namely the cathode and the anode to form a grid-type photoconductive semiconductor switch, the performance is greatly improved, namely the ohmic contact, the voltage resistance and the heat dissipation characteristics of the electrode and the transition layer and GaAs/SiC are greatly improved, the switching speed is faster, the voltage resistance is higher, the bandwidth of electromagnetic waves generated by the photoconductive semiconductor switch is expanded, the bearable power density is higher, the voltage resistance can reach more than 20KV, the service life can reach more than ten thousand times, while the photoconductive switch in the prior art has the voltage resistance of about 10KV and the short service life of only thousands of times; the electric field obtained on the semiconductor substrate by adopting the front and back electrodes is not only on the surface, so that the damage of a switch caused by the fact that the electrodes are easy to strike is avoided, meanwhile, the generated photocurrent passes through a fixed channel (current channel) by adopting a three-dimensional grid structure, namely, the generated photocurrent is changed into bulk current, the whole volume of the semiconductor substrate is utilized, the current density is reduced, or the withstand voltage is improved by orders of magnitude under the same current density;

secondly, the high-power ultra-wideband electromagnetic wave generated by the graphene film photoconductive semiconductor switch has wider bandwidth and covers the working waveband of most electronic equipment (such as unmanned aerial vehicles, missiles and the like), so that the high-power ultra-wideband electromagnetic wave can enter a circuit of the electronic equipment from a front door and a back door (holes, gaps and the like) in a coupling manner to interfere and damage electronic elements;

the photoconductive semiconductor switch based on the graphene film can generate the advantages of high peak power, narrow pulse, low trigger jitter and higher repetition frequency electric pulse, and lays a solid foundation for developing a light-operated array active ultra-wideband radar which has small volume and light weight, low interception probability, high resolution, strong anti-electromagnetic interference and anti-stealth capability, and integrates short-distance electromagnetic interference and medium-distance target detection, and electronic targets such as an interference damage unmanned aerial vehicle and a missile;

and the photoconductive switch has the advantages of high power density, high response speed, low trigger jitter, strong anti-electromagnetic interference capability, small volume, easy integration and the like, and has wide application prospect in the fields of large-current ignition devices, rejection weapons, high-power microwave systems, THz technology, impulse radar, 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 in the present invention, in which 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 disposed on the same side of the present invention;

fig. 3 is a sectional view of fig. 2 in a side view state;

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific embodiments.

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

The concrete structure is as follows:

a photoconductive semiconductor switch based on a graphene film comprises a semiconductor substrate 1 with a grid-type 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, and the second transition layer 5, the second graphene film 6 and the anode 7 may be disposed on the same side or opposite sides.

The semiconductor substrate 1 is made of one of gallium arsenide or silicon carbide with a purity of 99.999% or more, and a periodic groove, i.e., a gate structure 8, is 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 other metals can be used.

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

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

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

The working principle is as follows: the strip laser pulse triggers the corresponding grid structure semiconductor, under the bias of an electric field, the GaAs/SiC of the photoconductive material (semiconductor substrate) absorbs photons to generate electron-hole pairs, and outputs a large-amplitude electric pulse 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 generated pulse is, the wider the frequency band of the generated ultra-wideband electromagnetic pulse is. The carrier mobility of graphene at room temperature is about 15000cm²And V · s), and has very good heat conduction performance, and the addition of the graphene film greatly improves ohmic contact, voltage resistance and heat dissipation characteristics of the electrode, the transition layer and the GaAs/SiC, and has faster switching speed, higher voltage resistance and higher bearable power density.

In summary, the addition of the strip-shaped light spot matching grid structure and the graphene film further improves the heat dissipation characteristic and the performance of the switch. The voltage resistance, power, bandwidth, repetition frequency and service life of the pulse power device formed by the method are greatly improved. The problems of low voltage resistance, short service life, low repetition frequency and the like of the photoconductive semiconductor switch are solved, and the photoconductive semiconductor switch as a core device of an interference machine, a radar and the like directly influences the achievable power level and the fighting distance.

The above are merely representative examples of the many specific applications of the present invention, and do not limit the scope of the invention in any way. All the technical solutions formed by the transformation or the equivalent substitution fall within the protection scope of the present invention.

Claims

1. A graphene film based photoconductive semiconductor switch, characterized by: the graphene oxide thin film solar cell comprises a semiconductor substrate (1) with a grid type 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).

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. A graphene film based photoconductive semiconductor switch in accordance with 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 in accordance with 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 to 5, wherein: the first graphene film (3) and the second graphene film (6) are single-layer graphene, and the thickness is in the order of mum.

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

8. The graphene film-based photoconductive semiconductor switch of claim 7, wherein: on the laser irradiation side, a periodic groove is etched on the semiconductor substrate (1), the width of the groove is 1mm-3mm, the length of the groove is 10mm-20mm, and the depth of the groove is 3 mm.