New materials will increase the radar detection range by 50 times
Modern
combat is a war based on electronic technology.
Whoever has the
advantage of electronic equipment can seize the electromagnetic power
and seize it. The dominance of battlefield information. In the case of
one-way transparency, the enemy is attacked. The performance of the
electronic device is closely related to the material.
For example, the
F-16 and F-22 use active phased array radar, but the materials are
completely different and the performance is very different. .
The
material mentioned here refers to the semiconductor material, which
measures the main index power/mass ratio and reaction sensitivity of the
semiconductor material. The former describes how much the device power
is at a certain quality, and the latter describes the device's working
state conversion and small signal detection capability.
The US F-22 airborne radar AN/APG-77
uses a semiconductor based on gallium nitride, and its electron mobility
and mass-to-power ratio are improved relative to conventional GaAs
radar, 5 to 10 times. This means that in the same radar and the same
quality, the target can be detected more than 1.5 times the opponent's
distance, which will inevitably bring great tactical advantages.
A paper published by Professor
Xu Yuzhen entitled "Interfacial Solution Method for Synthesizing
Semiconductor Two-Dimensional Polymers" is very noteworthy, indicating
that China has the ability to prepare two-dimensional semiconductor
materials in the laboratory, and the power of this material will be
large. Amplitude improves the performance of electronic devices.
The
so-called two-dimensional semiconductor is relatively three-dimensional
semiconductor, this semiconductor is very thin, only one by thickness
The atomic composition of electrons in such semiconductors is very fast
compared to bulk three-dimensional semiconductors.
This is because,
limited to the three-dimensional space environment, after the voltage is
applied, although the electrons in the semiconductor partially move in a
substantially certain direction, the whole will fly in a
three-dimensional space, and most of the motion energy is consumed. In a
two-dimensional semiconductor, electrons cannot move to the third
dimension, which greatly increases the current. How much is this
performance increase?
The conclusion of the National Nanoscience Center
paper is that the power quality ratio is 1000 times! Reaction
sensitivity exceeds 6000 times!
What does this mean? I will give you
the calculation of this account.
The detection range of the
radar is proportional to the power of the fourth power of the
sensitivity. After using this material, the same volumetric radar will
be able to achieve 50 times the existing radar!
Taking the F-22 as an
example, the RCS minimum value is 0.0001m2, which can reduce the
detection distance of the existing radar to the normal fighter by 13
times.
An airborne radar capable of detecting 150 kilometers can only
find F-22 near 10 kilometers, but when the radar uses two-dimensional
semiconductor materials, it can find the F-22 at 576km.
Considering
that the stealth capability of the stealth aircraft is almost at the
limit, especially it is difficult to reduce the minimum value, so it can
be said that once the species.
When the radar is put into production,
the myth of the stealth plane can no longer be reproduced.
In addition,
it should be noted that this new material has the advantages of
softness and plasticity. Under the influence of this feature, it is also
possible to study the conformal radar antenna array that can be
attached to the surface of the aircraft.
Two-dimensional
semiconductor materials generally have thermal stability, which makes
it possible to control by chemical methods, the general method It is a
chemical vapor phase transport method that first synthesizes a
semiconductor alloy block and then uses a mechanical lift-off method for
preparation.
In the case of dichalcogenide, the chemical vapor
transport method refers to placing a single component powder material
and a certain amount of transport reagent in a vacuum quartz tube, and
the quartz tube is placed in a certain amount.
The temperature gradient
of the reaction tube, and finally placed one end in a high temperature
environment, one end placed in a low temperature environment, in the low
temperature area will grow alloy monomer ingots.
By repeated
mechanical stripping, a two-dimensional disulfide material can be
produced on a substrate of about 30 nm, but this method is rough, time
consuming, and difficult to mass produce.
Later, scientists invented
physical vapor deposition and chemical vapor deposition.
Physical
vapor deposition refers to the direct evaporation of a single component
powder source at high temperatures and the deposition of condensation
at low temperatures. A single-layer two-dimensional semiconductor
material is obtained, and the temperature gradient in the deposition
zone is extremely critical. If the operation is normal, a
two-dimensional semiconductor film is finally obtained.
Chemical vapor
deposition refers to the use of an oxide and a material to be prepared
as a reaction source, which is volatilized at a specific high
temperature and undergoes a chemical reaction, and finally a film of a
two-dimensional semiconductor material is deposited in the vicinity of
the container.
The research group of Professor Xu Yuzhen is to
improve the chemical vapor deposition method, using 1,4-trisonitrile to
synthesize nitrile trimerization at the interface between
dichloromethane and trifluoromethanesulfonic acid. Two-dimensional
containing triazine polymer, this two-dimensional polymer has excellent
dispersibility in organic solvents.
This makes it possible to form a
flexible polymer film with a fixed size by simply filtering, and even
more magically, it can be suitably fabricated into a field effect
transistor device and directly used for various electronic semiconductor
components.
However, we should also see that the idea of developing this material
is good, but it is still very practical. The road to the far is going.
Two-dimensional semiconductor materials can only exist in a small part
of the laboratory, which is costly, and there is currently no way to
solve the problem of large-scale manufacturing.
If you can make a few
millimeters at a time, it is already at the top of the world. Moreover,
the manufacture of a few millimeters has been to concentrate all the
human and material resources of the entire laboratory for a long time.
However, two-dimensional semiconductor materials are the development
direction of future radar electronic systems, both China and the United
States are engaged, but now they are just in their infancy.