InN Monolayer Research Articles

Adsorption characteristics of Ni cluster Modified-InN monolayer for indoor noxious gases (CH2O, C6H6, and NH3)

With the continuous enhancement of people's health awareness and the pursuit of high-quality life, the noxious gases generated after the renovation of new houses are receiving more attention. The gas sensing properties of InN monolayer modified with Ni clusters (1–3 Ni atoms) on CH2O, C6H6, and NH3 were analyzed based on DFT calculations, including the adsorption energy, charge transfer, density of states, bandgap structure, molecular orbitals, electrostatic potential, and desorption time investigation of gas adsorption systems. Moreover, different numbers of Ni atoms were introduced and their adsorption energies were analyzed. The results showed that the intrinsic InN and Ni–InN were suitable materials for gas sensors, while Ni2–InN and Ni3–InN were more suitable as adsorbents for clearing these three gases. The change in conductivity upon gas adsorption provides a theoretical basis for identifying the concentration of mixed gases of CH2O, C6H6, and NH3.

Metal-Decorated InN Monolayer Senses N2 against CO2.

Poor selectivity is a common problem faced by gas sensors. In particular, the contribution of each gas cannot be reasonably distributed when a binary mixture gas is co-adsorbed. In this paper, taking CO2 and N2 as an example, density functional theory is used to reveal the mechanism of selective adsorption of a transition metal (Fe, Co, Ni, and Cu)-decorated InN monolayer. The results show that Ni decoration can improve the conductivity of the InN monolayer while at the same time demonstrating an unexpected affinity for binding N2 instead of CO2. Compared with the pristine InN monolayer, the adsorption energies of N2 and CO2 on the Ni-decorated InN are dramatically increased from -0.1 to -1.93 eV and from -0.2 to -0.66 eV, respectively. Interestingly, for the first time, the density of states demonstrates that the Ni-decorated InN monolayer achieves a single electrical response to N2, eliminating the interference of CO2. Furthermore, the d-band center theory explains the advantage of Ni decorated in gas adsorption over Fe, Co, and Cu atoms. We also highlight the necessity of thermodynamic calculations in evaluating practical applications. Our theoretical results provide new insights and opportunities for exploring N2-sensitive materials with high selectivity.

Optical excitations of graphene-like materials: group III-nitrides.

By using first-principles calculations, we have studied the electronic and optical characteristics of group III-nitrides, such as BN, AlN, GaN, and InN monolayers. The optimized geometry, quasi-particle energy spectra, charge density distributions, band-decomposed charge densities, and Van Hove singularities in density of states are described in the work using physical and chemical pictures and orbital hybridizations found in B-N, Al-N, Ga-N, and In-N chemical bonds. Moreover, the dielectric functions, energy loss functions, absorption coefficients, and reflectance spectra with electron-hole interactions of optical properties are successfully achieved. More importantly, the close relations between electronic and optical properties are successfully demonstrated. The theoretical framework will be useful to research other graphene-like materials.

Adsorption and gas sensing properties of Co modified InN to SF6-N2 mixture decomposition components

• It is the first time that Co-InN is used as the adsorbent to remove the decomposition components of SF 6 -N 2. • Co-InN shows good adsorption properties to NO 2 , SOF 4 , SOF 2 , SO 2 F 2 by chemisorption. • The theoretical calculation results are important to guide the development of resistive gas sensor based on the Co-InN. This paper presents a detection method of partial discharge decomposition components of SF 6 -N 2 mixture by Co-doped InN. The severity of partial discharge in gas insulated switchgear (GIS) can be judged by the gas components when SF 6 -N 2 decomposes. Exploring sensors with excellent gas-sensing detection capabilities can provide method to partial discharge decomposition component detection and fault diagnosis of GIS. Undoped InN is a wide bandgap semiconductor with good sensing properties. In this paper, the adsorption of SF 6 -N 2 decomposition components on Co-doped InN monolayer, as well as the adsorption mechanism and gas sensitivity characteristics were investigated by density functional theory (DFT), including adsorption energy, charge transfer, the density of state theory and molecular orbital theory. Our calculations found that Co-doped InN has the optimal structure at the T N site and has good adsorption performance for NO 2 , SOF 4 , SOF 2 , and SO 2 F 2 gas molecule. All adsorption reactions belong to chemisorption. These results could direct the development of gas sensor based on the Co-doped InN monolayer, and provides methods to online monitoring of GIS discharge failures.

Room temperature ferromagnetism and transport properties in InN/VTe2 van der Waals heterostructures

The room temperature ferromagnetism can be induced for nonmagnetic pristine graphene-like InN monolayer through establishing van der Waals heterostructure with ferromagnetic semiconductor, which could be applied for realizing novel low-dimensional spintronic devices. Here, we investigate the electronic structure and magnetic properties of InN/VTe2 van der Waals heterostructure under strain and electrostatic doping by first-principles calculations. The InN/VTe2 van der Waals heterostructure possesses desired physical properties such as a symmetric band alignment, ferromagnetic ground state, large in-plane magnetic anisotropy energy of 1.54 meV, and high Curie temperature of 354 K. Meanwhile, the band alignment and magnetic anisotropy energy for InN/VTe2 van der Waals heterostructure can be also tuned effectively by strain. Significant enhancement of conductivity and robust above room temperature ferromagnetism exhibit in InN/VTe2 van der Waals heterostructure under electrostatic doping and paves a new route toward a low-dimensional spintronic field-effect transistor.

Two-dimensional XY monolayers (X = Al, Ga, In; Y = N, P, As) with a double layer hexagonal structure: A first-principles perspective

In this paper, we systematically investigate the structural, mechanical, optical and electronic properties of novel two-dimensional XY (X= Al, Ga, In; Y= N, P, As) monolayers in the double layer hexagonal structure (DLHS) using first-principles calculations. Our calculations show that single-layers of XY are stable, with the exception of GaP monolayer, which is unstable with its phonon spectrum containing negative frequencies. Also, the linear elastic parameters confirm the Born conditions for mechanical stability of XY monolayers and they are brittle structures. Most XY monolayers have indirect semiconductor characteristics with band gaps of 3.54 eV, 1.78 eV, 0.18 eV, 1.68 eV and 1.28 eV for AlN, GaN, InN, AlP, and AlAs monolayers. However the GaAs monolayer has a metallic character. The optical results indicate the InN and AlAs monolayers have ability to absorb the visible light spectra. We expect that our findings will point the way forward for the use of these structures in microelectronics and optoelectronics devices.

Magnetic properties in a IIIA-nitride monolayer doped with Ag: A density functional theory investigation

We present a density functional theory study on the electronic structures and magnetism of IIIA-nitride (AlN, GaN and InN) monolayer doped with Ag atoms. The results show that the IIIA-nitride binary compounds doped with low concentrations of Ag atoms are spin-polarized with 2.0 µB. Among them, single layer AlN and GaN doped with Ag atoms both demonstrate two possible ground states: ferromagnetic and antiferromagnetic. In contrast, Ag-doped InN monolayer only exhibits ferromagnetic ground state with half-metallicity. Moreover, different doping concentration of Ag atoms results into various half-metal band-gaps. With increasing the concentration of Ag atoms, the energy gap of corresponding system significantly decreases. Under some suitable concentrations and sites of doped-Ag atoms, robust room-temperature ferromagnetism even can be realized in these systems. The above work shows a rich variety of electronic and magnetic properties in IIIA-nitride monolayer induced by Ag doping, which provides a simple and effective method to design new electronic and spintronic devices based on layered nanomaterials.

Electronic and optical properties of metallic nitride: A comparative study between the MN (M = Al, Ga, In, Tl) monolayers

The electronic and the optical properties of metallic nitride (MN) monolayers are studied using a DFT formalism. In most of these monolayers, the electron density of the metallic atoms is much higher than that of the nitride atoms, and ionic, covalent, and metallic bonds are found in M-N bonds, resulting in fascinating electronic and optical properties. The optical band gap is varied from almost 0.0 to 3.0eV for the MN monolayers depending on the bond type between the metallic and the nitride atoms, as well as the contribution of the type of orbitals around the Fermi energy. The optical properties such as the dielectric function, the excitation spectra, the refractive index, the reflectivity, and the optical conductivity of MN monolayers are calculated. The excitation energy and static dielectric constant are found to be inversely proportional to the band gap at low photon energy, and the refractive index at energy approaching zero for the incident light is found to be 2.302, 1.93, 1.37, and 1.306 for TlN, InN, GaN, and AlN monolayers, respectively, in the case of parallel electric field. The MN monolayers with a large band gap have good visible light functionality, while the MN monolayers with a lower band gap are found to be active in the infrared region. Furthermore, it is shown that the optical properties of MN monolayers show a strong anisotropy with respect to the polarization of the incoming light. It is found that the optical conductivity of TlN is twice that of InN, GaN, and AlN at low energy. Our results for the optical properties of MN monolayers show that they could be beneficial in optoelectronic device applications.

Adsorption of H2 and C2H2 onto Rh-decorated InN monolayer and the effect of applied electric field

InN monolayer with graphene-like morphology and desirable electronic property is a promising candidate for gas sensing application. In this paper, we study the adsorption and sensing performances of the Rh-decorated InN (Rh–InN) monolayer upon two typical dissolved gases in the transformers oil, namely H2 and C2H2, to explore its potential to evaluate the working condition of the transformers. Rh atom conducts n-doping on the pristine InN surface with E b of −2.01 eV. Also, chemisorption is determined for H2 and C2H2 adsorption on the Rh–InN surface given that the E ad of −0.88 and −2.15 eV, respectively. The opposite changing trend of E g in H2 and C2H2 systems manifests the resistance-based sensing mechanism for selective detection of two gas species. The applied electric field supports the work function analysis that an Rh–InN monolayer possesses a strong potential for field-effect transistor sensor application in terms of H2 and C2H2 detection, wherein the charge-transfer in the gas systems is tunable by altering the voltage. Moreover, the excessive electric field is not considered to be suggestible since it can impact the geometric stability of the Rh–InN monolayer. This theoretical work is meaningful to exploit novel sensing 2D materials to guarantee the good operation of the power system. Highlights Rh-decorating behaviors upon InN monolayer is studied. Expound the potential of Rh-InN monolayer for dissolved gas analysis in transformers. Analyze the effect of applied electric field on gas adsorptions.

Adsorption and Sensing Properties of Dissolved Gas in Oil on Cr-Doped InN Monolayer: A Density Functional Theory Study

Dissolved gas analysis (DGA) is recognized as one of the most reliable methods in transformer fault diagnosis technology. In this paper, three characteristic gases of transformer oil (CO, C2H4, and CH4) were used in conjunction with a Cr-decorated InN monolayer according to first principle calculations. The adsorption performance of Cr–InN for these three gases were studied from several perspectives such as adsorption structures, adsorption energy, electron density, density of state, and band gap structure. The results revealed that the Cr–InN monolayer had good adsorption performance with CO and C2H4, while the band gap of the monolayer slightly changed after the adsorption of CO and C2H4. Additionally, the adsorption property of the Cr–InN monolayer on CH4 was acceptable and a significant response was simultaneously generated. This paper provides the first insights regarding the possibility of Cr-doped InN monolayers for the detection of gases dissolved in oil.

Adsorption Performance of Noble-Metal Decorated InN Monolayer to CO: A Computational Study

In this paper, based on density functional theory (DFT), the adsorption properties of four noble metal(Au, Ag, Pd and Rh) decorated InN monolayers to CO were investigated. The results indicate that the decorated InN monolayers with Pd, Ag and Au dopant have excellent adsorption capacities for CO, and the adsorption energies are −1.366, −0.948 and −1.318 eV, respectively. Density of states (DOS) and deformation charge density (DCD)analysis were adopted to further analysis of the electronic structure of the adsorption system. Besides, the change in the band gap of each system before and after adsorption was calculated based on the frontier orbital theory and desorption time of CO from each decorated InN monolayer was estimated to evaluate its potential applications in the sensor field.

Strain tailored thermodynamic stability, electronic transitions, and optoelectronic properties of III (In, Ga and Al)-nitride monolayers

The thermodynamic stability of III-nitride monolayers is calculated using the phonon band structure. Electronic properties are computed using the generalized gradient approximation-Perdew–Burke–Ernzerhof exchange-correlation potentials, which show the semiconducting behavior with bandgap 0.59 eV, 2.034 eV, and 2.906 eV for InN, GaN, and AlN monolayers, respectively. The biaxial tensile and compressive strains are used as external stimuli to understand their impact on the optoelectronic properties of these monolayers. The thermodynamic stability of strained monolayers is investigated to explore the maximum possible strains, i.e. flexibility limit, these monolayers can sustain. These monolayers are more sensitive to compressive strains, showing thermodynamic instability even at 1% compressive strain for all the considered monolayers. Further, the III-nitride monolayers are more robust with the tensile strain. InN, GaN, and AlN monolayers can sustain up to 4%, 16%, and 18% tensile strain, respectively. More interestingly, the electronic transitions, such as direct to indirect and semiconducting to metallic, are noticed with strain in the considered monolayers. The optical properties also exhibit strong strain dependency at the different transition points.

First-principles investigation upon H2 and C2H2 adsorptions on the Ag-decorated InN monolayer for gas sensor development

This work using the first-principles theory investigates the adsorption behavior of Ag-decorated InN (Ag-InN) monolayer upon H2 and C2H2, in order to realize the dissolved gas analysis (DGA) in transformer oil. The Ag-decorating analysis indicates that the TN site is most energy-favorable with binding energy (Eb) of −1.26 eV. Physisorption is identified for H2 system while chemisorption for C2H2 system given the calculated adsorption energy (Ead) of −0.46 and −0.92 eV, respectively. Given the desirable C2H2 sensing response of 58.3% obtained by the frontier molecular orbital theory and the recovery property obtained by van’t-Hoff-Arrhenius expression, we conclude that Ag-InN monolayer is a promising recyclable resistance-type sensor for C2H2 detection at room temperature, while is not suitable for H2 detection because of the small sensing response and quite short recovery time. Our calculations can provide the guidance to explore novel sensing materials for application in the field of power system as promising gas sensors.

Strong tribo-piezoelectric effect in bilayer indium nitride (InN)

The high electronegativity between the atoms of two-dimensional (2D) group-III nitrides makes them attractive to demonstrating a strong out-of-plane piezo-electricity effect. Energy harvesting devices can be predicted by cultivating such salient piezoelectric features. This work explores the tribo-piezoelectric properties of 2D-indium nitride (InN) as a promising candidate in nanogenerator applications by means of first-principles calculations. In-plane interlayer sliding between two InN monolayers leads to a noticeable rise of vertical piezoelectricity. The vertical resistance between the InN bilayer renders tribological energy by the sliding effect. During the vertical sliding, a shear strength of 6.6–9.7 GPa is observed between the monolayers. The structure can be used as a tribo-piezoelectric transducer to extract force and stress from the generated out-of-plane tribo-piezoelectric energy. The A–A stacking of the bilayer InN elucidates the highest out-of-plane piezoelectricity. Any decrease in the interlayer distance between the monolayers improves the out-of-plane polarization and thus, increases the inductive voltage generation. Vertical compression of bilayer InN produces an inductive voltage in the range of 0.146–0.196 V. Utilizing such a phenomenon, an InN-based bilayer compression-sliding nanogenerator is proposed, which can tune the generated tribo-piezoelectric energy by compressing the interlayer distance between the InN monolayers. The considered model can render a maximum output power density of ~ 73 mWcm−2 upon vertical sliding.

First-Principles Study of Au-Doped InN Monolayer as Adsorbent and Gas Sensing Material for SF6 Decomposed Species.

As an insulating medium, sulfur hexafluoride (SF6) is extensively applied to electrical insulation equipment to ensure its normal operation. However, both partial discharge and overheating may cause SF6 to decompose, and then the insulation strength of electrical equipment will be reduced. The adsorption properties and sensing mechanisms of four SF6 decomposed components (HF, SO2, SOF2 and SO2F2) upon an Au-modified InN (Au-InN) monolayer were studied in this work based on first-principles theory. Meanwhile, the adsorption energy (Ead), charge transfer (QT), deformation charge density (DCD), density of states (DOS), frontier molecular orbital and recovery property were calculated. It can be observed that the structures of the SO2, SOF2 and SO2F2 molecules changed significantly after being adsorbed. Meanwhile, the Ead and QT of these three adsorption systems are relatively large, while that of the HF adsorption system is the opposite. These phenomena indicate that Au-InN monolayer has strong adsorption capacity for SO2, SOF2 and SO2F2, and the adsorption can be identified as chemisorption. In addition, through the analysis of frontier molecular orbital, it is found that the conductivity of Au-InN changed significantly after adsorbing SO2, SOF2 and SO2F2. Combined with the analysis of the recovery properties, since the recovery time of SO2 and SO2F2 removal from Au-InN monolayer is still very long at 418 K, Au-InN is more suitable as a scavenger for these two gases rather than as a gas sensor. Since the recovery time of the SOF2 adsorption system is short at 418 K, and the conductivity of the system before and after adsorption changes significantly, Au-InN is an ideal SOF2 gas-sensing material. These results show that Au-InN has broad application prospects as an SO2, SOF2 and SO2F2 scavenger and as a resistive SOF2 sensor, which is of extraordinary meaning to ensure the safe operation of power systems. Our calculations can offer a theoretical basis for further exploration of gas adsorbent and resistive sensors prepared by Au-InN.

Cr doped MN (M = In, Ga) monolayer: A promising candidate to detect and scavenge SF6 decomposition components

In this paper, the adsorption properties of Cr modified InN (Cr-InN) and GaN (Cr-GaN) monolayers to SF6 decomposed components were investigated based on the density functional theory (DFT). Results reveal that these two graphene-like materials exhibit strong adsorption capacity for the three decomposed species SO2, SOF2 and SO2F2. Remarkable adsorption energy, significant charge transfer and molecular deformation indicate the occurrence of chemisorption. The hybridization of atomic electron orbitals in the density of states calculation verifies the strong chemical interaction between the gases and two monolayers. According to this strong adsorption capacity, Cr-InN and Cr-GaN monolayers demonstrate their potential as gas Scavenger for removing SF6 decomposition products in the insulation equipment. Besides, the significant change in conductivity of the monolayer caused by gas adsorption makes it possible to explore gas sensors based on Cr-InN and Cr-GaN monolayer. This paper indicates that Cr-doped InN and GaN monolayers can be used as adsorbents and sensors to guard the operation status of SF6 insulation devices by detecting and scavenging SF6 decomposed components.

Analysis of InGaN-Delta-InN Quantum Wells on InGaN Substrates for Red Light Emitting Diodes and Lasers

Modern multi-color RGB micro-light emitting diode (μLED) displays and digital micro-mirror laser projectors often require the use of both III-V and III-Nitride material systems for different pixel/laser colors. This is due primarily to the conventionally low efficiencies of red emitters based on the InGaN materials system, which is used to create green and blue emitters for RGB displays. The main challenges for InGaN red emitters are the quantum confined stark effect (QCSE) and the difficulty of incorporating high In-content into the active region. In this work, InGaN/InGaN/delta-InN quantum wells (QWs) on InGaN substrates are proposed and demonstrated to show significant enhancement in electron-hole wavefunction overlap ( Γe_hh ) and spontaneous emission radiative recombination rate (Rsp) in the red emission regime. Analysis of InGaN/InGaN/delta-InN QWs with InGaN barriers emitting at 630 nm was performed using a self-consistent six-band $k \cdot p$ formalism. The Γe_hh was shown to increase by more than 230% compared to an InGaN/InGaN QW emitting at 630 nm, leading to significant increases in Rsp and internal quantum efficiency ( ηIQE ). With growth of InN monolayers on InGaN now readily achievable, this novel active region design could pave the way for high-efficiency, native red-emitting InGaN LEDs and lasers.

Sensing behaviors of transition metal decorated InN monolayer upon $$\hbox {SO}_{2}$$ and NO molecules: a first-principles study

Sensing behaviors of transition metal decorated InN monolayer upon $$\hbox {SO}_{2}$$ and NO molecules: a first-principles study

First principles calculation of structural, electronic and optical properties of (001) and (110) growth axis (InN)/(GaN)n superlattices

Based on the full potential linear muffin-tin orbitals (FPLMTO) calculation within density functional theory, we systematically investigate the electronic and optical properties of (100) and (110)-oriented (InN)/(GaN)n zinc-blende superlattice with one InN monolayer and with different numbers of GaN monolayers. Specifically, the electronic band structure calculations and their related features, like the absorption coefficient and refractive index of these systems are computed over a wide photon energy scale up to 20 eV. The effect of periodicity layer numbers n on the band gaps and the optical activity of (InN)/(GaN)n SLs in the both growth axis (001) and (110) are examined and compared. Because of prospective optical aspects of (InN)/(GaN)n such as light-emitting applications, this theoretical study can help the experimental measurements.

First-principles study on the electronic structures and magnetic properties of InN monolayer doped with Cr, Fe, and Ni

Abstract The electronic structures and magnetic features of 3d transition metals (TM) Cr-, Fe-, Ni-doped InN monolayers are studied by using density functional calculations. The results show that doping these transition metals into InN monolayer can generate magnetic moments, which are primarily distributed in the 3d atoms and their neighboring N atoms. The Cr- and Fe-doped InN monolayers are magnetic semiconductors, while the Ni-doped InN monolayer shows a half-metallic characteristic. The ferromagnetic (FM) and antiferromagnetic (AFM) couplings of Cr-, Fe-, and Ni-doped InN monolayers are also investigated. It is found that the Cr-doped InN monolayer may exhibit the room-temperature ferromagnetism. Finally, under the biaxial tensile strains, for these magnetically doped InN monolayers, semiconductor-metal phenomenon can be observed.