Effect of Thin Film Thickness on the Electronic Properties of Wurtzite Structure (ZnO and GaN): A Density Functional Theory Study

Abstract:

By using first-principle density-functional theory (DFT) calculations supplemented with symmetry analysis, we investigated the effect of thin-film thickness on the electronic properties of non-polar ( ZnO-wz and GaN-wz. We find that the electronic band structures of thin-film non-polar ( surface with layer variations from two until ten bilayers show the Rashba spin splitting. Importantly, we revealed that this splitting is found to be strongly anisotropic observed in the valence band maximum (VBM) around the Γ point. We clarified the origin of the anisotropic spin splitting in the electronic band structures by considering the point-group symmetry (PGS) of the present system. We found that the changes of the PGS from C_6v (for polar [0001] direction) to C_s (for non-polar ( direction) are responsible for inducing the anisotropic of the spin splitting. To further confirm the anisotropic splitting, we calculated the Rashba spin splitting parameters for different directions of the k-path. We found that these parameters are different in magnitude for a different direction of the k-path indicating the anisotropic spin splitting quantitatively, which is consistent well with symmetry analysis. Finally, we conclude that the observed Rashba spin splitting in the wurtzite surface structure is promising for spintronics applications.

• Periodical: Key Engineering Materials (Volume 884)
• Pages: 394-404
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.884.394
• Online since: May 2021
• Authors: Tin Subekti Zaidah Darajat, Moh. Adhib Ulil Absor*
• Keywords: Rashba Spin Splitting, Surface Effects, Thin Film Thickness, Wurtzite

References

[1] Awschalom, D. and N. Samarth, 2009, Spintronics without Magnetism, Physics 2, 50 (2009).

DOI: 10.1103/physics.2.50

[2] Kato, Y., Myers, R. C., Driscoll, C. D., Gossard, A. C., Levy, J. and Awschalom, D. D, 2003, Gigahertz Electron Spin Manipulation Using Voltage-Controlled G-Tensor Modulation, Science, 299 (February), p.1201–1205.

DOI: 10.1126/science.1080880

[3] Manchon, A., H. C. Koo, J. Nitta, S. M. Frolov, and R. A. Duine , 2015, New Perspectives for Rashba Spin-Orbit Coupling,.

DOI: 10.1038/nmat4360

[4] Kuhlen, S., K. Schmalbuch, M. Hagedorn, P. Schlammes, M. Patt, M. Leesa, G. Güntherodt, and B. Beschoten, 2012, Electric Field-Driven Coherent Spin Reorientation of Optically Generated Electron Spin Packets in InGaAs. Phys. Rev. Lett. 109, 146603.

DOI: 10.1103/physrevlett.109.146603

[5] Ando, Y., 2013, Topological Insulator Materials, J. Phys. Soc. Jpn. 82, 102001,.

[6] Datta, S. and Das, B., 1990, Electronic Analog of The Electro‐Optic Modulator, Applied Physics Letters, 56(7), p.665–667,.

DOI: 10.1063/1.102730

[7] Žutić, I., J. Fabian, and S. D. Sarma, 2004, Spintronics: Fundamentals and Applications, Rev. Mod. Phys.76, 323.

DOI: 10.1103/revmodphys.76.323

[8] Palummo, M., C. M. Bertoni, L. Reining, and F. Finocchi, 1993, The Electronic Structure of Gallium Nitride. Physica B 185 (1993) 404-409.

DOI: 10.1016/0921-4526(93)90269-c

[9] Stampfl, C. and C. G. Van de Walle. 1999. Density-Functional Calculations For III-V Nitrides using The Local-Density Approximation and The Generalized Gradient Approximation, Phys. Rev. B 59, 5521.

DOI: 10.1103/physrevb.59.5521

[10] Esquivel-Sirvent, R. and Cecilia Noguez, 1998, Electron energy loss for anisotropic systems: Application to GaN 1010. Phys. Rev. B 58, 7367,.

DOI: 10.1103/physrevb.58.7367

[11] Chen, Chen., Mitra Dutta and Michael A. Stroscio, 2004, Electron scattering via interactions with optical phonons in wurtzite crystals, Phys. Rev. B 70, 075316.

DOI: 10.1103/physrevb.70.075316

[12] Lu, Ming-Pei., Chieh-Wei Chen and Ming-Yen Lu, 2016, Charge-Separation Kinetics of Photoexcited Oxygen Vacancies in ZnO Nanowire Field-Effect Transistors, Physical Review Applied 6, 054018.

DOI: 10.1103/physrevapplied.6.054018

[13] Lü, T. and J. C. Cao, 2005, Confined optical phonon modes and electron-phonon interactions in wurtzite GaN/ZnO quantum wells J, Phys. Rev. B 71, 155304 s2005d.

DOI: 10.1103/physrevb.68.165335

[14] Schmidt, W. G., M. D. Neumann, E. Speiser and N. Esser, 2015, GaN m-plane: Atomic structure, surface bands, and optical response, Phys. Rev. B 91, 035302.

DOI: 10.1103/physrevb.91.035302

[15] Botsch, L., I. Lorite, Y. Kumar, and P. Esquinazi, 2017, Indirect Experimental Evidence of A Persistent Spin Helix in H + Implanted Li-Doped ZnO By Photogalvanic Spectroscopy, Physical Review B 95, 201405(R),.

DOI: 10.1103/physrevb.95.201405

[16] Kozulin, A. S. and A. I. Malyshev, 2019, General Condition for Realizing A Collinear Spin-Orbit Effective Magnetic Field in Two-Dimensional Electron Systems and Its Application to Zinc-Blende and Wurtzite Quantum Wells, Phys. Rev. B 99, 035305,.

DOI: 10.1103/physrevb.99.035305

[17] Bychkov, Yu A. and E.I Rashba, 1984, Properties of a 2D Electron Gas with Lifted Spectral Degeneracy, JETP Letter Vol 39 No. 2.

[18] Absor, MAU., F Ishii, H Kotaka, and M Saito, 2015, Persistent Spin Helix on Wurtzite ZnO Surface: First-Principles Density-Functional Study, Applied Physics Express 8 (7), 073006.

DOI: 10.7567/apex.8.073006

[19] Perdew, J.P., K. Burke, M. Ernzerhof, 1996, Generalized Gradient Approximation Made Simple, Phys. Rev. Lett. 77, 3865.

DOI: 10.1103/physrevlett.77.3865

[20] Ozaki, T, H. Kino, J. Yu, M.J. Han, M. Ohfuchi, F. Ishii, K. Sawada, Y. Kubota, Y.P. Mizuta, T. Ohwaki, T.V.T Duy, H. Weng, M. Toyoda, Y. Okuno, R. Perez, P.P. Bell, M. Ellner, Y. Xiao, A.M. Ito, M. Kawamura, K. Yoshimi, C.-C. Lee, and K. Terakura, 2016, User's manual of OpenMX Ver. 3.8. http://www.openmx-square.org/.

[21] Troullier, N and Jose Lurs Martins, 1991, Efficient Pseudopotentials for Plane-wave Calculation, Phys. Rev. B 8 Volume 43, Number 3, 1993 (1991).

DOI: 10.1103/physrevb.43.1993

[22] Ozaki, T and H. Kino, 2004, Numerical atomic basis orbitals from H to Kr, Phys. Rev. B 69, 195113.

DOI: 10.1103/physrevb.69.195113

[23] Ozaki, T, 2003, Variationally optimized atomic orbitals for large-scale electronic structures, Phys. Rev. B 67, 155108.

DOI: 10.1103/physrevb.67.155108

[24] Gil, B., 2014, Physics of Wurtzite Nitrides and Oxides: Passport to Devices, Oxford University Press.

[25] Kartzel, H, W. Pretzel, M. Kofferlein, W. Sciessi, M. Steiner, U. Hiller, G.M Kalvius, D.W. Mitchell, T.P. Das, P. Blaha, K. Schwartz, and M.P Pasternak, 1996, Lattice dynamics and hyperfine interactions s in ZnO and ZnSe at high external pressures, Phys. Rev. B Volume 53, Number 17,.

DOI: 10.1103/physrevb.53.11425

[26] M. Catti, Y. Noel, and R. Dovesi, 2003, Full Piezoelectric Tensors of Wurtzite and Zinc-Blende ZnO and ZnS by First-Principles Calculations. Journal of Physics and Chemistry of Solids 64 2183–2190.

DOI: 10.1016/s0022-3697(03)00219-1

[27] L. Weston, X. Y. Cui, B. Delley, dan C. Stampfl, 2012, Band Offsets and Polarization Effects in Wurtzite ZnO/Mg 0.25 Zn 0.75 O Superlattices From First Principles. Phys. Rev. B 86, 205322.

DOI: 10.1103/physrevb.86.205322

[28] Silva, W. S., C. Stiehler, E. A. Soares, E. M. Bittar, J. C. Cezar, H. Kuhlenbeck, H. J. Freund, E. Cisternas, and F. Stavale, 2018, Hydrogen-Induced Metallization on The ZnO (0001) Surface, Phys. Rev. B 98, 155416.

DOI: 10.1103/physrevb.98.155416

[29] Kuykendall, T., P.J. Pauzauskie, Y. Zhang, J. Goldberger, D. Sirbully, J. Denlinger and P.Yang, 2004, Crystallographic Alignment of High-Density Gallium Nitride Nanowire Arrays, Nature Materials Vol. 3.

DOI: 10.1038/nmat1177

[30] Jaffe, J. E., R. Pandey and P. Zapol, 1996, Ab Initio Prediction of Gan (101̄0) and (110) Anomalous Surface Relaxation, Phys. Rev. B Volume 53, Number 8.

[31] Hellström, M., D. Spångberg, K. Hermansson, dan P. Broqvist, 2012, Cu Dimer Formation Mechanism on The ZnO(101̄0) Surface, Phys. Rev. B 86, 235302. DOI:.

DOI: 10.1103/physrevb.86.235302

[32] Supatukul, C., S. Pramchu, A.P. Jaroenjittichai, Y. Laosiritaworn, 2016, Density Functional Theory Investigation of Surface Defects in Sn-doped ZnO, Surface and Coatings Technology Volume 298,.

DOI: 10.1016/j.surfcoat.2016.04.013

[33] Qi, L., Y. Qi, Z. Chai, Y.Q.M. Hellström, D. Spångberg, K. Hermansson, dan P Broqvist, 2019, Post-Annealing Induced Oxygen Vacancy Mediated NonPolar ZnO Films With Excellent Optoelectronic Performance, Ceramics International 45, 8388-8394.

DOI: 10.1016/j.ceramint.2019.01.147

[34] Lee, W. J. dan Y.S. Kim, 2011, Dimer-Vacancy Reconstructions of the GaN and ZnO(101̄1) Surfaces: Density Functional Theory Calculations, Physical Review B 84, 115318.

[35] Moshfegh, A. Z., H.V. Kanel, S.C. Kashyap, M. Wuttig, 2003, Proceedings of the International Workshop on Physics and Technology of Thin Films I W T F. World Scientific Publishing Co. Pte. Ltd.

[36] Cotton, F. A., 1990, Chemical Applications of Group Theory, A Wiley-Interscience Publication.

[37] Tamborenea, Pablo I., Thomas Wellens, Dietmar Weinmann, and Rodolfo A. Jalabert, 2017, Spin-relaxation time in the impurity band of wurtzite semiconductors, Phys. Rev. B 96, 125205.

DOI: 10.1103/physrevb.96.125205