photoelectric sensor

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.

Force.

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

0.09

Electric volts, while using

G0W0

Many of the plans

If the effects of matter are taken into account, the electronic spacing will become

2.31

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.

and,

Biaxial strain can be used to separate the optical band gap of a single layer of black phosphorus

From

0.38

Electric volt (

8%

Strain force)

2.07

Electric volt (

5.5%

Strain force). The combination of excitons is equally strong

Variable force sensitivity. Research shows that the compressive strain is

8%

Time volts

0.40

And the tensile strain is

4%

Time volts

0.83

. I

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.

1.

Introduction

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.

confirmed.

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

Black phosphorus

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,

semiconductor

P-n

Knot,

Solar cell applications, as well as due to its strong bandgap (

~0.9

Electric volt) and

MoS

2

Compared to having high carrier mobility

Rate-of-effect field effect transistor

FET

). Li et al. used a small layer of black phosphorus crystals and showed good stability at room temperature.

Transistors make field effect transistors (

FET

). 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.

Broken ratio.

Buscema

Et al. confirmed that black phosphorus relies on its traits as a reliable candidate for tunable optoelectronic test applications.

Such as

(

i

)

Field effect transistors require secondary operation in the dark.

(

Ii

)

Can be fast when illuminated

(on

Rise time reached

1

Meters per second) perceived broadband index (visible area up to

940

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 (

0.3-1.5

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.

Tran

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

1/

2

W

,

Zigzag

PNR

The state of the state shown is

1/W

Here

W

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.

PNR

Each

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.

recently,

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.

Rodin

Others use density functional theory and combined models,

Display

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.
Although
Definitions of although
conjunction
in spite of the fact that; even though.
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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

n addition,

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

Binding energy.

We have compiled the following chapters:

The second chapter introduces the electron and transmission characteristics of black phosphorus under strain force;

third

The investigation investigated the optical response of monolayer black phosphorus under biaxial strain; the fourth chapter summarizes our research results.

two.

Transmission characteristics

The electron transport volume of a single layer of black phosphorus is

TranSIESTA

Calculated in the self-consistent non-equilibrium state technology implemented in this

Technology and

SIESTA

Coded connection. double

-󰀀

(added polarization) numerical orbital basis set is used in

P

In the atomic energy. We are real

The use of modulo conservation in the space grid,

GGA/PBE

Functional theory and cutoff energy. Electronic transmission is along the armrest side

Calculation of the direction of the zigzag (see figure

1

). In order to obtain an accurate transmission spectrum, orthogonal to the direction of transmission

2D

cloth

The Liyuan area is used as the elastic limit for the period direction.

100

Grid sampling.

three.

Optical properties

Some people may think that exciton effects are due to weak shielding and low dimensionality

BP

Optical properties. If you want to describe it correctly

Description

Bp

Optical properties, many inter-entity effects must be taken into account. For this work, we are

V

ASP

Internal use

BSE

Method for calculating a single layer under compression and tensile strain

BP

spectrum. First, the mixture

DFT

Calculation use

GGA-PBE

Fully utilized single layer

BP

Structure

HSE06

The method is carried out. Next is a collision

GW

meter

Calculate the quasi-particle excitons. Finally, we take

BSE

Calculation

GW

High value for obtaining photon adsorption spectra

Including exciton effect

TD

Approximation method.

BSE

The calculation method is

Monkhorst-Pack

Methodologically

9󰀀13󰀀1

K-mesh

On the progress. Wave function and reaction

The energy impairment of the function is

400eV

with

200eV

.

We tried

112

with

326

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

0.05eV

within.

6

The highest used valence and

6

The lowest unused valence is used as the basis for excitons.

since

GW

Absorbing a lot of vacuum

band,

We use a vacuum zone at least

15A

To avoid false reactions in periodic images.

=0.05 eV

Complex change

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

BP

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

enlarged

Egap

when

BP

Single layer

Egap

Is calculated as

0.90eV

,

Consistent with the previous,

use

HSE06

Become

1.59eV

.

Many physical influences

e

Increase to

2.31eV

.

Previous theoretical studies are expected to rise or fall under tensile strain or compressive strain

Single layer

BP

of

Egap

. We observed not only

Egap

and

Eopt

with

Eexc

Both are sensitive to application strain. because

So, by tuning the strain,

BP

Optical properties can be easily repaired. in contrast,

Eexc

in

MoS2

It is difficult to change under a single layer

change. Single layer under test

BP

Optical gap is approximately

1.45eV

,

This with the calculation

1.61eV

Consistent. Last time

During the test, when

BP

Was placed

SIO2

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.

0.7eV

This is consistent with our theoretical work. Mention that this calculated exciton binding energy and its single layer

Semiconductor compatible. E.g

MoS2.e

Has been found to be a single layer

MoS2

of

1eV

. Another point is. In the electronic band

When the gap increases rapidly, the tensile strain rises due to the weakening of the insulator shield.

“xy=4%

Extended machine bundle

Binding.

It is worth mentioning that,

When used on one hand

PBE

Wave function and eigenvalue as

GW

Calculate input instead of

HSE06

,

Eopt

Yes

1.30eV

Instead of

1.61eV

,

HSE

For calculating the importance of quasiparticles and optical gaps.

As mentioned in the previous section, when

“xy=8%

Time,

GGA-PBE

Expected single layer

BP

Transition from semiconductor metals. however

HSE06

with

GoWo

Expected

BP

Is an indirect band gap semiconductor at strain value

0.32eV

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,

in

GW

found

MoS2

Than

GGA-PBE

It was found to be bigger. Therefore, to accurately predict the conversion value,

GW

Calculation is the key.

Figure 6 shows a single layer

BP

Optical adsorption spectrum

x,y

Have different strain values,

We also showed the use

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