On the electronic properties of the boron nitride oxide by density functional · PDF...

1 Aceptado en J. Copm. Theor. Nanosci.

On the electronic properties of the boron nitride oxide by

density functional theory

E. Chigo Anota1,A, A. Bautista Hernández2, C. F. Solanes Rivas1, Gregorio H.

Cocoletzi3

1Cuerpo Académico de Ingeniería en Materiales-Facultad de Ingeniería Química,

Benemérita Universidad Autónoma de Puebla, C.U. San Manuel. C. P. 72570, Puebla,

México.

2Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, Apdo. Postal J-39,

Puebla, Pue., 72570, México

3Instituto de Física ‘Luís Rivera Terrazas’, Benemérita Universidad Autónoma de Puebla,

Apartado Postal J-48, Puebla 72570, México.

A [email protected]

We analyze the electronic properties of boron nitride oxide (BNO) sheets using the

density functional theory within the local density approximation, in a similar form as

reported by Sota et al., [Diamond Relat. Mater. 17, 826 (2008)]. The BNO sheets with the

chemical composition of B27N27H18+O, are represented by the circular arm-chair model.

Six different configurations are considered to investigate the interaction of oxygen atoms

with the sheets. These models depend upon the position of the O atom. In C1 the atom

bonds to 2 N atoms, in C2 the atom bonds to 2 B atoms, in C3 the atom is on top of a B

atom, in C4 the atom is on top of a N atom, in C5 the O bonds to a B-N dimer of a hexagon,

and in C6 the O bonds to a B and to a N within the plane of the hexagon. Results of the

total energy and the vibration frequency of each configuration yield C5 as the most stable

structure with the formation of an epoxy group. This low energy atomic geometry displays

high polarity with semiconductor behavior. By analyzing the possible carbon migration into

the BNO sheet we conclude that the O is only physisorbed on the surface to form CO.

Keywords: Boron nitride oxide, migration, DFT theory.


1. Introduction

Current technological advances have made possible the preparation of hexagonal boron

nitride sheets [1] in a similar fashion as graphene, which opens the possibility to built new

optoelectronic devices. Boron nitride nanotubes have been recently constructed to be used

in the fabrication of DVD’s with high storage capacity [2]. Nevertheless exist some

theoretical and experimental works that deal with boron nitride nanostructures. On the other

hand, theoretical [3,4] and experimental [5] works on graphene have been reported to deal

with the surface chemical modification by oxidation with oxygen and other functional

groups [6, 7] yielding the graphene oxide.

In a recent paper Chigo et al [8] investigated boron nitride nanosheets in two different

configurations: In the first structure a functionalized group is bonded to boron and in the

second the functionalized group is bonded to nitrogen. The functionalized groups are OH,

COOH and O atoms in the group epoxy. The results showed the formation of epoxy

structures on the surface with the structure displaying high polarity (15.84 and 6.55 D, for

the first and second configuration, respectively) and semiconductor behavior.

On the other hand, Sota et al [9] have prepared and characterized films of boron nitride

oxide. The experimental characterization has been done using infrared spectroscopy

yielding an energy gap in the regime of 5.3 a 5.9 eV with the results depending on the

sample oxidation. To understand the electronic properties of materials obtained from boron

nitride [10, 11], in this work we address the problem of the interaction of oxygen with

boron nitride sheet. In addition we shall analyze the possible carbon migration into the

boron nitride oxide lattice.


2. Computational Tools

First principles total energy calculations have been performed following the procedure

reported in previous works [12-22]. We have applied the density functional theory (DFT)

[23-26], developed by Kohn during the 1960 decade, as implemented in DMOL3 quantum

chemistry code [27-29]. The exchange-correlation energy has been treated according to the

local density approximation with the Perdew-Wang (PWC) [30] parameterization. The

double polarized atomic base has been used to represent the electron states. The base

includes the hydrogen p-orbital, carbon, boron, nitrogen and oxygen d-orbitals, which allow

performing all-electron calculations to account for the core (DNP) [27-29]. We have

considered multiplicity equal to 1 (singlet) and charge equal to 0 (neutral) for the circular

arm-chair cluster with chemical composition B27N27H18+O (Figure 1) for all models in our

work. Clusters have a diameter of 1.35 nm.

To determine the best functional to be used in our studies we have tested GGA in the PBE

parameterization and LDA in the PWC parameterization. The results show negligible

differences in the energy gap. Concerning the atomic lattice parameter have not been

obtained differences. Therefore, we conclude that the use of either PBE or PWC functional

is good for our numerical studies. We choose to work with the LDA (PWC) functional. For

the base set we have used a cut radius of 0.40 nm with a self consistent tolerance of 1.0 x

10-6 Ha. The most stable configurations have been determined applying the minimum

energy and positive frequency criteria [31]. Afterwards we calculate bond lengths, dipolar

moment, and the energy band gap (ebg). The ebg is obtained as the energy difference

between the HOMO and LUMO [32] energies.


To validate the model we have calculated the cohesive energies using the formula

[Ec=[nE(B)+mE(N)+kE(H)-EBnNmHk]/(n+m+k)], where n, m, and k label the atoms in the

system, in a similar fashion as done for the graphene [7] and gallium nitride [14] sheets. To

explore the size dependence we have used the following structures: naphthalene (B5N5H8),

pyrene (B8N8H10), coronene (B12N12H12), and a cluster with a chemical composition

B27N27H18. Variations on the cohesive energy, energy band gap, and bond lengths for the

considered clusters are less than 1%, which indicate that the size does not affect

significantly the system properties. We shall mention that the model used in the present

work has been previously employed by Chigo [12] to study 2D carbon structures, and the

doping of graphene and boron nitride sheets. Similarly it has been invoked to investigate

elastic properties of graphene [3], transport properties [33], electronic properties of group

III-A nitrides nanosheets [15] or nanotubes [34], the H2O adsorption on 2D boron nitride

[16], the doping of the boron nitride sheet with Li and F [17], and the electronic properties

of silicon carbide pure and doped with N [19].

To explore the possible carbon migration into the BNO lattice we determine the

configuration of minimum energy of the following systems: BNO (B27N27H18+O) + C in

different atomic geometries (Figure 3) and the doped system when the C atom replaces the

B and the N (Figure 4).

3. Results and Discussion 3.1 Structure of Boron Nitride Oxide

Using the circular arm-chair model for the BNO sheet we obtain C5 as the most stable

structure (Figures 1a-1e). The resulting structure displays arm-chair chirality in agreement


with the theoretical report of Martinez et al [35], and experimental work of You et al., [36,

37].This optimized configuration is (quite similar to) the initial geometry, where the O is

bonded to the B-N hexagon of the epoxy type (see Table I, and Figs. 1d and 2b), when

compared with models C2 and C6 (Figs. 2a and 2c) they display similar final

configurations.

In all analyzed configurations the final geometry displays the structure of the epoxy group

in the same side of the surface, except C6 where the epoxy structure is formed in the

opposite side of the original orientation, below the BNO lattice (Figure 2c). The most stable

configuration obtained in our studies agrees with for boron nitride oxide reported by Chigo

et al. [8]; however, in this last case the presence of the hydroxyl (OH), carboxyl (COOH),

and oxygen induce the formation of the epoxy group. The B-N bond length in the most

stable structure remains unaltered with value 1.44 Å (Table II), in contrast to that of the

same oxide with additional functional groups reported in the literature [8]. These functional

groups induce the sheet to bend, in addition to be enlarged by a factor of 1.02 (considering

the bond length 1.41 Å) as comparison with the graphene oxide [7]; this in turn indicates

that the functional groups in both cases affect the sheet surfaces.

The BNO sheet polarity (3.19 D, Table II) is smaller, by a factor of 4.96, that configuration

C1 (15.84 D), and by a factor of 2.06, that configuration C2 (6.55 D), reported in the

literature [8]. Moreover, this polarity is smaller by a factor of 2.03 than that of the graphene

oxide (D. M.= 6.47 D). The high polarity is produced by the presence of functional groups

adsorbed on the surface of both graphene oxide and boron nitride oxide, which also

produce charge redistribution on the carboxyl and epoxy groups, according to the HOMO

and LUMO orbitals [8]. Experimental evidences demonstrate that BN sheets are ionic [38].

We have obtained that electronic structure of the system agrees well with that reported in


the literature, in particular the ebg= 3.64 eV. The BN sheet displays an ebg=4.84 eV, the

BNO sheets in the C1 geometry exhibits an ebg=1.2 eV, and in the C2 geometry has an

ebg=2.25 eV, according with those reported by Chigo et al., [8]. These electronic

characteristics contrast with displayed by the graphene oxide circular sheet, which exhibits

a semimetal behavior (ebp=0.42 eV) [7], suggesting that the oxygen atom might induce

changes in the ebg value.

3.2 Analysis of the carbon migration into the Boron Nitride Oxide

Sota et al., [9] have reported that during the sample preparation of boron nitride oxide films

carbon atoms may be incorporated in the lattice. This fact has motivated the molecular

simulation to determine either the carbon migration into the lattice or the adsorption on the

surface. Considering the most stable configuration of the BNO, we have studied its

interaction with a carbon atom, see Figs. 3a-3e. The results of the total energy indicate that

the most stable atomic geometry is C3 as indicated in Table III. This result agrees with that

one corresponding to the positive vibration frequency. The final configuration is planar

with the formation of a CO molecule with a C-O bond length of 1.136 Å and a separation

distance of 2.86 Å of the molecule from the sheet.

Finally, we have explored the structures when the carbon atom replaces either the boron

(Figure 4a) or the nitrogen (Figure 4b). The results show configuration 1 as the most stable

geometry against configuration 2 with an energy difference of 29.8 a. u. By comparing

these energies with that of C3, we conclude that these differences are small. It suggests that

the carbon atom may not migrate into the BNO lattice instead preferring to be adsorbed on

the surface with the formation of CO molecule (Figure 3c). Both structures 1 and 2 retain

the planar geometry, with B-N bond length similar to that reported in the literature [12].


However, configuration 1 exhibits larger polarity (12.78 D; Figure 4), 4 times the polarity

of configuration 2 (3.19 D; Figure 4b) with configuration 1 behaving as semimetal (ebp=

0.45 eV) and configuration 2 behaving as a semiconductor (ebp=2.62 eV).

Conclusions

We have presented molecular simulation calculations to study the structural stability of

BNO sheets with the composition including an oxygen atom. According to the reported

work from Sota et al the final structure contains a functional epoxy group in all cases

studied. This is also in agreement with the work of Chigo et al on the BNO sheets provided

that we may consider two possible configurations for the BNO sheets: one formed by the O,

OH and COOH groups and the other one the structure synthesize by Sota et al in the shape

of thin film. Our results indicate that the structures behave as semiconductors with high

polarity. Finally, we have obtained that the migration of carbon into the boron nitride lattice

does not take place; instead the carbon atom prefers to be adsorbed on the surface to form a

carbon oxide molecule.

Acknowledgments

This work has been supported by projects Vicerrectoria de Investigación y Estudios de

Posgrado-Benemérita Universidad Autónoma de Puebla (CHAE-ING13-G, BAHA-ING-

12-G), Cuerpos Académicos de Ingeniería en Materiales (BUAP-CA-177), Física

Computacional de la Materia Condensada (BUAP-CA-194), and Propiedades Mecánicas,

Electrónicas y Estructurales de Materiales (BUAP-CA-236). The work of GHC was

partially supported by Consejo Nacional de Ciencia y Tecnología (83982).

References

[1] Novoselov KS, Jiang D, Schedin F, Booth TJ, Khotkevich VV, Morozov SV, Geim AK

(2005) Proc. Natl Acad Sci USA 102:10451-10453


[2] Serrano J, Bosak A, Arenal R, Krisch M, Watanabe K, Taniguchi T, Kanda H, Rubio A,

Wirtz L (2007) Phys Rev Lett 98:095503-095504

[3] Li Z, Zhang W, Luo Y, Yang J, Hou JG, (2009) J Am Chem Soc 131: 6320-6321

[4] Zhang W, Carravetta V, Li Z, Luo Y, Yang J, (2009) J Chem Phys 131:244505-6

[5] Mkhoyan KA, Contryman AW, Silcox J, Stewart DA, Eda G, Mattevi C, Miller S,

Chhowalla M, (2009) NanoLett 9 (3): 1058-1063

[6] Li X, Wang H, Robinson JT, Sanchez H, Diankov G, Dai H, (2009) J Am Chem Soc

131: 15939-15944

[7] Hernández Rosas JJ, Ramírez Gutiérrez RE, Escobedo Morales A, Chigo Anota E

(2011) J Mol Model 17:1133-1139

[8] Chigo Anota E, Salazar Villanueva M and Hernández Cocoletzi H (2011) J Nanosci

Nanotech 11:5515-5518

[9] Sota H, Komatsu N, Chikamatsu K, Kimura C, Aoki H, Sugino T, (2008) Diamond

Relat Mater 17: 826-829

[10] Watanabe K, Taniguchi T, Kanda H, (2004) Nature Mater 3: 404-409

[11] Shimada Y, K. Chikamatsu, Kimura C, Aoki H, Sugino T, (2006) Appl Surf Sci 253:

1459-1463

[12] Chigo Anota E (2009) Sup y Vac 22 (1):19-23

[13] Rangel NL, Seminario JM, (2008) J Phys Chem A 112: 13699-13705

[14] Chigo Anota E, Hernández Cocoletzi H (2011) J Mol Model. 18: 591-596

[15] Chigo Anota E, Salazar Villanueva M, Hernández Cocoletzi H (2010) Phys Stat Solidi

C 7:2252-2254

[16] Chigo Anota E, Salazar Villanueva M (2009) Sup y Vac 22 (2):23-28

[17] Chigo Anota E, Salazar Villanueva M, Hernández Cocoletzi H (2010) Phys Stat Solidi

C 7:2559-2561

[18] Chigo Anota E, Hernández Cocoletzi H and Rubio Rosas E, (2011) Eur Phys J D

63:271-273

[19] Chigo Anota E, Hernández Cocoletzi H, Bautista Hernández A, Sánchez Ramírez JF

(2011) J Comput Theor Nanosci 8:637-641

[20] Chigo Anota E, Escobedo Morales A, Salazar Villanueva M, Vázquez Cuchillo O,

Rubio Rosas E (2012) J. Mol Model DOI:10.1007/s00894-012-1612-z


[21] Tüzün B, Erkoç Ş (2012) Quantum Matt 1:136-148

[22] Kohn W, Becke AD, Parr RG (1996) J Phys Chem 10:12974-12980

[23] Jones RO, Gunnarsson O (1989) Rev Modern Phys 61:689-746

[24] Kohn W (1999) Rev Mod Phys 71:1253-1266

[25] Parr R, Yang W (1989) Density Functional Theory of Atoms and Molecules, 1st edn.

Oxford University Press, USA

[26] Kohn W, Sham LJ, (1965) Phys Rev A 140: A1133-A1138

[27] Delley B (1990) J Chem Phys 92:508-608

[28] Delley B (1996) J Phys Chem 100:6107-6110

[29] Delley B (2000) J Chem Phys 113:7756-7765

[30] Perdew JP, Wang Y (1992) Phys Rev B 45:13244-13249

[31] Foresman JB, Frisch Æ (1996) Exploring Chemistry with Electronic Structure

Methods, 2nd edn. Gaussian Inc, USA, p 70

[32] Sohlberg K, Vedova-Brook N, (2004) J Comp Theor Nanosci 1(3): 256-260

[33] Ono T, Fujimoto Y, Tsukamoto S (2012) Quantum Matter 1:4-19

[34] Srivastava A, Sharma M, Tyagi N, Kothari S L (2012) J Comp Theor Nanosci 9: 1693-

1699

[35] Martínez JI, Cabria I, López MJ, Alonso J (2009) J Phys Chem C 113:939-941

[36] You YM, Ni Zh H, Yu T, Shen ZX (2008) Appl Phys Lett 93:163112-16113

[37] Tao C, Jiao L, Yazyev OV, Ch. Chen Y, Feng J, Zhang X, Capaz RB, Tour JM, Zettl

A, Louie SG, Dai H, Crommie MF (2011) Nature Phys 7: 616-620

[38] Alem N, Erni R, Kisielowski C, Rossell MD, Gannett W, Zettl A (2009) Phys Rev B

80:155425-155432


FIGURES AND TABLES CAPTIONS

FIGURE 1. The initial geometries of the BNO sheets considering a bond length 2.0 Å. B is represented by the pink atom, N in blue, H is represented by the white atom and O is in red. FIGURE 2. The final geometries of the BNO sheets in configurations C2, C5 and C6.

FIGURE 3. The initial configurations of the interaction of the carbon atom with the BNO sheet. Similar to Fig. 1 B is represented by the pink atom, N is presented in Blue color, H in white color, and C in red color.

FIGURE 4. The initial and final geometries of the doped BNO sheet a) with the carbon atom replacing boron and b) the carbon atom replacing the nitrogen. TABLE I. Total energy difference of configurations to model BNO sheets. The reference energy corresponds to the lowest minimum energy. TABLE II. Structural parameters of the different BNO models. TABLE III. The total energy differences of the BNO sheets interacting with a carbon atom. The reference energy corresponds to the lowest minimum energy.


CONFIGURATION TOP VIEW SIDE VIEW

C1

DRed-O= 2.0 Å

O bonds to 2 nitrogen atoms

C2

DRed-O= 2.0 Å

O bonds to2 boron atoms

a)

C3

DRed-O= 2.0 Å

O on top of a boron atom

b)

C4

DRed-O= 2.0 Å

O on top of a nitrogen atom

c)

C5

DRed-O= 2.0 Å

O bonds to a B-N dimer

d)

C6

DRed-O= 2.0 Å

O bonds to a N and a B within hexagon plane

e)

FIGURE 1


View Configuration C2 a)

Configuration C5 b)

Configuration C6 c)

Top

Side

FIGURE 2


figuration Top Side Final geometry

C1

On top of a N D(red-C)=2.0 Å

a)

D(red-C)=1.61 Å

C2

On top of a B D(red-C)=2.0 Å

b)

D(red-C)=1.61 Å

C3

On top of the hexagon

D(red-C)=2.0 Å

c)

D(red-CO)=2.86 Å Formation of C≡O

C4

Within the hexagon

d)

C5

On top of a B-N bond

D(red-C)=2.0 Å

e)

FIGURE 3


Configuration 1 Configuration 2

a) Total energy = -2232.5825261 a. u.

M. D. = 12.78 D ebp=0.45 eV

b) Total energy = -2202.7821607 a. u

M. D. = 3.19 D ebp= 2.62 eV

FIGURE 4

TABLE I

Configuration Energy difference eV/atom

C1 7.46E-4 C2 9.65E-6 C3 0.016 C4 8.96E-4 C5 0.0 C6 2.6E-5


TABLE II

System Bond length (Å) B-N

Dipolar moment (Debye)

10-3

EBP (HOMO-LUMO)

eV

BN [20]

1.44

13.4

4.84

BNO*

Configuration C5

1.45

3190

3.64

BNO C1 / [8] BNO C2

1.43 1.44

15840 6558.3

1.2 2.25

Graphene oxide [7,20]

1.41

6470

0.42

*This work.

TABLE III

Configuration Energy difference eV/atom

C1 0.106 C2 0.106 C3 0.0 C4 0.128 C5 0.106

On the electronic properties of the boron nitride oxide by density functional · PDF...

Documents

Transcript of On the electronic properties of the boron nitride oxide by density functional · PDF...