|Tuning the electronic and optical properties of a single layer of black phosphorus by strain force
From the first-principles calculation we can see that the electronic and optical properties of a single layer of black phosphorus strongly depend on the strain released.
Based on the heterogeneous atomic structure of black phosphorus,
Its electronic conductivity and optical reactivity are sensitive to the strain generated
The extent and direction of the.
We have found that the inclusion of many substances plays a necessary role in the formation of a single layer of black phosphorus.
The electronic spacing of unstrained monolayer black phosphorus measured by semi-local function is
Electric volts, while using
Many of the plans
If the effects of matter are taken into account, the electronic spacing will become
Electric volts. The tensile strain is used to reveal a single layer of black
The ability of phosphorus to transfer electrons in the zigzag direction can be significantly enhanced.
Biaxial strain can be used to separate the optical band gap of a single layer of black phosphorus
Electric volt (
Electric volt (
Strain force). The combination of excitons is equally strong
Variable force sensitivity. Research shows that the compressive strain is
And the tensile strain is
Our calculations confirmed that the optical reaction of black phosphorus is effective under strain.
This is also a promising way to set
A new type of photovoltaic device for obtaining a wide range of solar spectra.
The synthesis of single-layer graphene layers has led to the emergence of a new two-dimensional single-layer material in the field of condensed matter physics. People
It is believed that the synthesis and manufacturing development of single-layer crystallization in the future will pave the way for the exploration of many unique new materials. Now, single
Layer specific graphene layer,
Both transition metal sulfides and boron nitride are readily available, and some nanodevices have been used.
Although single-layer graphite is a magical two-dimensional material, its lack of electron spectral band gap makes people
Look for a band gap ultra-thin material similar to it.
Recently, a single layer of phosphor crystal (also called
The successful combination has sparked interest in this material. Single layer stone
The attractive material of the urethane layer can be used in a variety of electronic devices.
Such as a gas sensor,
Solar cell applications, as well as due to its strong bandgap (
Electric volt) and
Compared to having high carrier mobility
Rate-of-effect field effect transistor
). Li et al. used a small layer of black phosphorus crystals and showed good stability at room temperature.
Transistors make field effect transistors (
). In addition, Liu et al. also predicted the stability and structure of single-layer phosphor crystals.
Different characteristics. They observed high current, high field effect hole mobility, and Qualcomm in a few black phosphorus transistors.
Et al. confirmed that black phosphorus relies on its traits as a reliable candidate for tunable optoelectronic test applications.
Field effect transistors require secondary operation in the dark.
Can be fast when illuminated
Rise time reached
Meters per second) perceived broadband index (visible area up to
Nano). Theoretical research on wearing others in the near future
The study shows that the direct energy band gap of black phosphorus is determined by its number of layers (
Electric volts), and its vertical electric field can be used
Tune the bandgap.
Recently, an article has made an accurate and meticulous report on the importance of one to four layers of black phosphorus electronic structures and interlayer jumps.
And people also use density functional theory to study black phosphorus nanobelts.
The electronic structure of a single-layer black phosphorus nanobelt is reported.
And light absorption spectrum. They said that the band gap of the handrail is
The state of the state shown is
Expressed as the width of the nanoribbon. The width dependence of the bandgap depending on the direction is attributed to the electron
Non-relativistic with holes in the zigzag direction, and relativity in the vector direction.
Different electrons and holes have a light absorption spectrum and a different quality but a significant effect.
Han et al. pointed out that the passivated black phosphorus nanobelts
The electronic properties show a strong dependence on direction and strain forces.
Although the electronic and structural properties of single or small black phosphorus have been investigated, the role of strain in these properties
It is still a controversial issue.
Black phosphorus has been studied to have a negative Poisson’s ratio,
And it has a higher mechanical spirit
Activity allows us to use it in the harshest mechanical environments.
Others use density functional theory and combined models,
It shows that the pressure deformation of the crystal plane along the normal direction can change the size of the band gap and also trigger the transition of the semiconductor metal.
Definitions of although
in spite of the fact that; even though.
although the sun was shining it wasn’t that warm
synonyms: in spite of the fact that, despite the fact that, notwithstanding (the fact) that, even though, even if, for all that, while, whilst
Translations of although
Fei et al. reported that the anisotropy of free carrier mobility can be controlled by applying biaxial and uniaxial strain.
In the present
In this study we have studied how to change the electronic and optical properties of black phosphorus under biaxial strain.
How to calculate the excitons
We have compiled the following chapters:
The second chapter introduces the electron and transmission characteristics of black phosphorus under strain force;
The investigation investigated the optical response of monolayer black phosphorus under biaxial strain; the fourth chapter summarizes our research results.
The electron transport volume of a single layer of black phosphorus is
Calculated in the self-consistent non-equilibrium state technology implemented in this
Coded connection. double
(added polarization) numerical orbital basis set is used in
In the atomic energy. We are real
The use of modulo conservation in the space grid,
Functional theory and cutoff energy. Electronic transmission is along the armrest side
Calculation of the direction of the zigzag (see figure
). In order to obtain an accurate transmission spectrum, orthogonal to the direction of transmission
The Liyuan area is used as the elastic limit for the period direction.
Some people may think that exciton effects are due to weak shielding and low dimensionality
Optical properties. If you want to describe it correctly
Optical properties, many inter-entity effects must be taken into account. For this work, we are
Method for calculating a single layer under compression and tensile strain
spectrum. First, the mixture
Fully utilized single layer
The method is carried out. Next is a collision
Calculate the quasi-particle excitons. Finally, we take
High value for obtaining photon adsorption spectra
Including exciton effect
The calculation method is
On the progress. Wave function and reaction
The energy impairment of the function is
Empty band collection.
Since the number of empty belts
The amount seriously affects the corresponding position of the quasiparticle energy. Calculate the quasiparticle gap and exciton combination polymerization
The highest used valence and
The lowest unused valence is used as the basis for excitons.
Absorbing a lot of vacuum
We use a vacuum zone at least
To avoid false reactions in periodic images.
The aggregated spectrum is calculated and expanded.
Table 1 summarizes the calculated electronic gaps for different strain values, optical gap and exciton mixing energy, electron and
The optical properties as a biaxial strain diversity have been plotted in Figure 5. As shown in Table 1 and Figure 5, the use of the mixture is sharp
Is calculated as
Consistent with the previous,
Many physical influences
Previous theoretical studies are expected to rise or fall under tensile strain or compressive strain
. We observed not only
Both are sensitive to application strain. because
So, by tuning the strain,
Optical properties can be easily repaired. in contrast,
It is difficult to change under a single layer
change. Single layer under test
Optical gap is approximately
This with the calculation
Consistent. Last time
During the test, when
Surface, shield weakened combination, reduced exciton joint ability, and our simulation
It is also consistent.
Due to low dimensionality and weak shielding, our calculated data predicts a large exciton bound energy value.
This is consistent with our theoretical work. Mention that this calculated exciton binding energy and its single layer
Semiconductor compatible. E.g
Has been found to be a single layer
. Another point is. In the electronic band
When the gap increases rapidly, the tensile strain rises due to the weakening of the insulator shield.
Extended machine bundle
It is worth mentioning that,
When used on one hand
Wave function and eigenvalue as
Calculate input instead of
For calculating the importance of quasiparticles and optical gaps.
As mentioned in the previous section, when
Expected single layer
Transition from semiconductor metals. however
Is an indirect band gap semiconductor at strain value
In case. previous
Studies have shown that the calculated vertical compressive strain value is important to reduce the conversion of semiconductor metal under the double layer,
It was found to be bigger. Therefore, to accurately predict the conversion value,
Calculation is the key.
Figure 6 shows a single layer
Optical adsorption spectrum
Have different strain values,
We also showed the use