E-ISSN:2583-9152

Research Article

Ab-initio

Journal of Condensed Matter

2023 Volume 1 Number 1 Jan-Jun
Publisherwww.thecmrs.in

Ab-initio study of structural and electronic properties of Ga1-xScxN

Soni S1*Ahlawat D2
DOI:https://doi.org/10.61343/jcm.v1i01.3

1* Sahil Soni, Department Of Physics, Chaudhary Devi Lal University, Sirsa 125055, Hry, India.

2 Dharamvir Singh Ahlawat, Department Of Physics, Chaudhary Devi Lal University, Sirsa 125055, Hry, India.

In this work, we have calculated the structural and electronic properties of Sc doped GaN in different configurations. This study has been done using first principles full potential linearized argumented plane wave (FP-LAPW) method within the framework of Density Functional Theory. Here we used the generalized gradient approximation (GGA) of Perdew, Burke and Ernzerhof for exchange and correlation effects. Our results obtained for structural parameters and band structures are in good agreement with experimental results as well as other theoretical work.

Keywords: FP-LAPW, WIEN2K, GGA, Ab-initio Study, Electronic Properties

Corresponding Author How to Cite this Article To Browse
Sahil Soni, Department Of Physics, Chaudhary Devi Lal University, Sirsa 125055, Hry, India.
Email: 		Soni S, Ahlawat D, Ab-initio study of structural and electronic properties of Ga1-xScxN. J.Con.Ma. 2023;1(1):10-13.
Available From
https://jcm.thecmrs.in/index.php/j/article/view/3

Manuscript Received Review Round 1 Review Round 2 Review Round 3 Accepted
2023-05-10 2023-05-15 2023-05-20 2023-05-25 2023-06-01
Conflict of Interest Funding Ethical Approval Plagiarism X-checker Note
None Nil Yes 18.90%

© 2023by Soni S, Ahlawat D, and Published by Condensed Matter Research Society. This is an Open Access article licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/ unported [CC BY 4.0].

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Soni et al Ab-initio study of structural and electronic properties of Ga1-xScxN

Introduction

In semiconductor technology, group-III nitrides have great promise for semiconductor lasers, short-wavelength light-emitting diodes, optical detectors, high-power, high-temperature and high-frequency devices[1-3].The wurtzite, zinc blende, and rock salt crystal forms are typically shared by III-nitride semiconductors [4,5]. Wurtzite, which forms under normal conditions, has the most thermodynamically stable structure. By developing III-nitrides on cubic substrates like MgO, GaAs and Si , the zinc blende phase will be produced. It can only be attained at extremely high pressures for the rock salt phase [5].

GaN is wurtzite in its ground state structure. GaN is having ability to produce alloys and heterostructures with InN and AlN is another factor driving interest in the material. However, because InN has a low melting point, it cannot be alloyed with GaN at high temperatures.  As a result, InN needs to be replaced in these alloys. Because of their high strength and durability, transition metal nitrides have lately been proposed as possible replacements for InN [6].

A diversified family of materials with a wide range of technological uses is the transition metal (TM) nitrides. At ambient pressure, transition metal nitrides crystallize in the rocksalt structure. Since ScN and GaN have a very small (2%) lattice mismatch, they can be coupled to form GaN/ScN heterostructures or ScGaN alloys, which have been proposed as good replacements for InN [7-9]. In this work, we have used FP-LAPW method within the density functional theory to investigate the structural and electronic properties of Ga1-xScxN alloys with Sc concentration x = 0,0.25,0.50,0.75, and 1.0. As a function of composition, the projected lattice parameters and band gaps of these semiconducting nitride alloys in rocksalt and zinc blende structures are discussed. We have used modified Becke Johnson generalised gradient Approximation(mBJ+GGA) in combination with GGA (generalized gradient approximation) for obtaining accurate band gap estimation.

Materials and methods

The full-potential linearized augmented plane wave (FP-LAPW) method, as carrying out in the wien2k code, was used to perform the calculations

within the framework of Density Functional Theory (DFT) [10,11]. In this approach, the potential and wave function are enclosed in spherical harmonic functions inside nonoverlapping spheres enclosing the atomic sites muffin-tin spheres, and a plane wave basis accepted in remaining space of the unit cell interstitial area is used. The generalized gradient approximation (GGA), based on Perdew et al [12] form, was used to deal with exchange correlation effects. The valence includes the 3p, 3d, 4s, and 4p electrons of Ga, 2s and 2p electrons of N, and the 3s, 3p, 3d, and 4s electrons of Sc.

In our calculations, a supercell which is containing eight atoms (four shared between Sc and Ga and four N atoms) is used. For achieving different Sc concentrations, we replace one, two, three and all Sc atoms with Ga atoms to obtain concentrations of 75%, 50%, 25% and 0%, respectively. A plane wave cut-off  = 8/RMT (where RMT is the radius of muffin tin sphere ) was used. In present calculations, the value of the smallest muffin-tin radius around each atom spheres for Ga, Sc and N in the zinc blende phase to be 1.81, 1.81 and 1.56 a. u. respectively and in the rock-salt phase to be 1.87, 1.87, and 1.61 a.u. respectively. Inside the atomic sphere, the wave function expansion l was restricted to  = 10. A mesh of 63 and 64 special k-points were used for zinc blende and rock-salt structure respectively. All these values are tested for best convergence of energy and charge for the doped and undoped system.

Results and Discussion

Structural properties   

For the calculations of various solid properties, it is required to select an appropriate exchange correlation potential. We used the GGA (Generalized Gradient Approximation) exchange correlation potential within DFT to calculate the structural properties of Ga1-xScxN in different configurations. We used the experimental lattice parameter provided in reference [3] to calculate the structural properties of Ga1-xScxN in zincblende (B3) and rock-salt structure (B1). The total energy of a primitive unit cell is determined at various volumes. The equilibrium lattice constant, bulk modulus and pressure derivative were investigated by fitting the obtained data with Murnaghan equation of state [13]. The results for the equilibrium lattice constant a, bulk modulus B, and pressure derivative


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Soni et al Ab-initio study of structural and electronic properties of Ga1-xScxN

of the bulk modulus B' for the different concentrations are listed in Table 1.Here “a” refers to present work and “b” refers to calc. [14]

Table 1. Equilibrium lattice constant a, Bulk modulus B and Pressure Derivative B' for B1 and B3 phase of Ga1-xScxN at different concentrations of Sc.

CompositionLattice constanta(Å)Bulk modulusB (GPa)Pressure derivativeB' 
(x)B1B3B1B3B1B3
0.0 4.2715a4.27b 4.5516a4.55b213.01a195.00b 172.135a162.00b4.84a4.81b 4.31a4.53b
0.254.3528a4.36b 4.6546a4.66b196.286a189.00b 155.45a150.00b4.38a4.32b 4.08a4.14b
0.504.4191a4.42b 4.7461a4.75b188.306a183.00b145.764a147.00b4.45a4.17b 3.91a3.61b
0.754.4715a4.48b4.8235a4.83b191.052a185.00b 141.815a142.00b4.33a3.99b3.99a3.40b
1.04.5133a4.54b4.8918a4.91b197.172a180.00b 142.754a132.00b3.71a3.37b4.10a3.47b

Electronic properties:-

The calculated equilibrium lattice parameters of compound Ga1-xScxN in rock-salt and zincblende structure are used in the calculations of the electronic structure. With the exchange-correlation potential of the modified Becke-Johnson generalized-gradient approximation (mBJ-GGA), the electronic properties of Ga1-xScxN in rock-salt and zincblende phases is investigated. The FP-LAPW  method is used in the Brillion zone to evaluate the eigenvalues of the Kohn-Sham equation in specific high symmetry directions. Our calculated results for band gaps of different concentrations of Sc in different configurations are shown in table 2. From table 2, we have seen that the nature of band gap is indirect at x=0.0 of Ga1-xScxN in both zinc blende and rock-salt configuration.

Table 2.  Calculated Band Gaps of Ga1-xScxN in Rocksalt (B1) and Zinc blende (B3) with mBJ-GGA exchange corelation potential at different concentration (x) of Sc. Here “a” refers to present work and “c” refers to calc. [15]

Composition Band Gap(eV)Rock salt (B1) Band Gap(eV)Zinc blende(B3) Nature
0.02.617a 2.738a1.608c Indirect
0.251.699a2.857a1.850cDirect
0.501.175a3.262a2.060cDirect
0.750.968a3.477a2.410cDirect
1.00.896a3.626a2.870cDirect

Conclusion

In this paper, we are using FP-LAPW method within PBE-GGA exchange corelation functional to calculate the structural and electronic properties of Ga1-xScxN in rock-salt and zincblende configuration. It has

been observed that lattice parameters and volume of the cell is increased as the concentration of Sc is increased in both configurations. In contrast to structural properties, it is also noted that the band gap is increased as the concentration of Sc is increased in zincblende configuration but band gap is decreased as the concentration of Sc is increased in rock-salt configuration.

Acknowledgment

The author deeply acknowledges the UGC New Delhi for providing fellowship (JRF) to carry out the smooth research.

References

1. J. W. Orton and C. T. Foxon, Rep. Prog. Phys. 61, 1 (1998).

2. S. C. Jain, M. Willander, J. Narayan, and R. Van Overstraeten, J. Appl. Phys. 87, 965 (2000).

3. I. Vurgaftman and J. R. Meyer, J. Appl. Phys. 94, 3675 (2003).

4. Daoudi B, Boukraa A (2010) The structural and electronic properties of GaN under high pressure. Ann Sci Technol 2(1):19–26.

5. Moustakas T, Pankove J, Willardson R, Weber E (1999) Gallium nitride (GaN) II, vol 57. Academic Press, San Diego.

6. M. G. Moreno-Armenta, L. Mancera, and N. Takeuchi, Phys. Status Solidi B 238, 127 (2003).

7. M. E. Little and M. E. Kordesch, Appl. Phys. Lett. 78, 2891 (2001).

8. V. Ranjan, S. Bin-Omran, L. Bellaiche, and A. Alsaad, Phys. Rev. B 71,195302 (2005).

9. V. Ranjan, S. Bin-Omran, D. Sichuga, R. S. Nichols, L. Bellaiche, and A. Alsaad, Phys. Rev. B 72, 085315 (2005).

10. Hohenberg P, Kohn W (1964) Inhomogeneous electron gas. Phys Rev 136(3B):B864–B871.

11. Blaha P, Schwarz K, Madsen GK, Kvasnicka D, and Luitz J (2001) WIEN2K, an augmented plane wave+ local orbitals program for calculating crystal properties. In:
Schwarz K (ed), Vienna University of Technology, Austria.


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Soni et al Ab-initio study of structural and electronic properties of Ga1-xScxN

12. Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77(18):3865–3868.

13. Murnaghan FD (1944) On the theory of the tension of an elastic cylinder. Proc Natl Acad Sci USA 30(12):382–384.

14. Zerroug, S.; Sahraoui, F.A.; Bouarissa, N. Ab initio calculations of structural properties of ScxGa1-xN. J. Appl. Phys. (2008), 103, 063510.

15. Yurdasan N.B., Gulebaglan S.E,Tunali A.Y.,Akyuz G.B. First principles investigations of bowing parameters in zinc-blende ScxGa1-xN Philosophical Magazine Letters, (2014),94,724-731


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