Coherent-interface-induced strain in large lattice-mismatched materials: A new approach for modeling Raman shift
),
Download citation
652
Views
22
Downloads
8
Crossref
7
WoS
8
Scopus
0
CSCD
Strain engineering as one of the most powerful techniques for tuning optical and electronic properties of III-nitrides requires reliable methods for strain investigation. In this work, we reveal, that the linear model based on the experimental data limited to within a small range of biaxial strains (< 0.2%), which is widely used for the non-destructive Raman study of strain with nanometer-scale spatial resolution is not valid for the binary wurtzite-structure group-III nitrides GaN and AlN. Importantly, we found that the discrepancy between the experimental values of strain and those calculated via Raman spectroscopy increases as the strain in both GaN and AlN increases. Herein, a new model has been developed to describe the strain-induced Raman frequency shift in GaN and AlN for a wide range of biaxial strains (up to 2.5%). Finally, we proposed a new approach to correlate the Raman frequency shift and strain, which is based on the lattice coherency in the epitaxial layers of superlattice structures and can be used for a wide range of materials.
menu
Coherent-interface-induced strain in large lattice-mismatched materials: A new approach for modeling Raman shift
),
Abstract
Strain engineering as one of the most powerful techniques for tuning optical and electronic properties of III-nitrides requires reliable methods for strain investigation. In this work, we reveal, that the linear model based on the experimental data limited to within a small range of biaxial strains (< 0.2%), which is widely used for the non-destructive Raman study of strain with nanometer-scale spatial resolution is not valid for the binary wurtzite-structure group-III nitrides GaN and AlN. Importantly, we found that the discrepancy between the experimental values of strain and those calculated via Raman spectroscopy increases as the strain in both GaN and AlN increases. Herein, a new model has been developed to describe the strain-induced Raman frequency shift in GaN and AlN for a wide range of biaxial strains (up to 2.5%). Finally, we proposed a new approach to correlate the Raman frequency shift and strain, which is based on the lattice coherency in the epitaxial layers of superlattice structures and can be used for a wide range of materials.
References(88)
Wu, W. Z.; Wang, Z. L. Piezotronics and piezo-phototronics for adaptive electronics and optoelectronics. Nat. Rev. Mater. 2016, 1, 16031.
Wang, D. H.; Liu, X.; Fang, S.; Huang, C.; Kang, Y.; Yu, H. B.; Liu, Z. L.; Zhang, H. C.; Long, R.; Xiong, Y. J. et al. Pt/AlGaN nanoarchitecture: Toward high responsivity, self-powered ultraviolet-sensitive photodetection. Nano Lett. 2021, 21, 120–129.
Bishop, S. G.; Hadden, J. P.; Alzahrani, F. D.; Hekmati, R.; Huffaker, D. L.; Langbein, W. W.; Bennett, A. J. Room-temperature quantum emitter in aluminum nitride. ACS Photonics 2020, 7, 1636–1641.
Tamariz, S.; Callsen, G.; Stachurski, J.; Shojiki, K.; Butté, R.; Grandjean, N. Toward bright and pure single photon emitters at 300 K based on GaN quantum dots on silicon. ACS Photonics 2020, 7, 1515–1522.
Arita, M.; Le Roux, F.; Holmes, M. J.; Kako, S.; Arakawa, Y. Ultraclean single photon emission from a GaN quantum dot. Nano Lett. 2017, 17, 2902–2907.
Zhou, Y.; Wang, Z. Y.; Rasmita, A.; Kim, S.; Berhane, A.; Bodrog, Z.; Adamo, G.; Gali, A.; Aharonovich, I.; Gao, W. B. Room temperature solid-state quantum emitters in the telecom range. Sci. Adv. 2018, 4, eaar3580.
Growden, T. A.; Storm, D. F.; Cornuelle, E. M.; Brown, E. R.; Zhang, W. D.; Downey, B. P.; Roussos, J. A.; Cronk, N.; Ruppalt, L. B.; Champlain, J. G. et al. Superior growth, yield, repeatability, and switching performance in GaN-based resonant tunneling diodes. Appl. Phys. Lett. 2020, 116, 113501.
Qi, M.; Li, G. W.; Ganguly, S.; Zhao, P.; Yan, X. D.; Verma, J.; Song, B.; Zhu, M. D.; Nomoto, K.; Xing, H. L. et al. Strained GaN quantum-well FETs on single crystal bulk AlN substrates. Appl. Phys. Lett. 2017, 110, 063501.
Diez, S.; Mohanty, S.; Kurdak, C.; Ahmadi, E. Record high electron mobility and low sheet resistance on scaled-channel N-polar GaN/AlN heterostructures grown on on-axis N-polar GaN substrates by plasma-assisted molecular beam epitaxy. Appl. Phys. Lett. 2020, 117, 042102.
Chen, H. D.; Wang, P.; Wang, X. Y.; Wang, X. F.; Rao, L. J.; Qian, Y. P.; Yin, H. J.; Hou, X. H.; Ye, H. P.; Zhou, G. F. et al. 3D InGaN nanowire arrays on oblique pyramid-textured Si (311) for light trapping and solar water splitting enhancement. Nano Energy 2021, 83, 105768.
Wang, P.; Chen, H. D.; Wang, H.; Wang, X. Y.; Yin, H. J.; Rao, L. J.; Zhou, G. F.; Nötzel, R. Multi-wavelength light emission from InGaN nanowires on pyramid-textured Si(100) substrate grown by stationary plasma-assisted molecular beam epitaxy. Nanoscale 2020, 12, 8836–8846.
Wang, P.; Chen, H. D.; Wang, H.; Wang, D.; Song, C. K.; Wang, X. Y.; Yin, H. J.; Rao, L. J.; Zhou, G. F.; Nötzel, R. Inter-facet composition modulation of III-nitride nanowires over pyramid textured Si substrates by stationary molecular beam epitaxy. Nano Res. 2021, 14, 1502–1511.
Siladie, A. M.; Jacopin, G.; Cros, A.; Garro, N.; Robin, E.; Caliste, D.; Pochet, P.; Donatini, F.; Pernot, J.; Daudin, B. Mg and In codoped p-type AlN nanowires for pn junction realization. Nano Lett. 2019, 19, 8357–8364.
Xu, H. Q.; Jiang, J. A.; Dai, Y. J.; Cui, M.; Li, K. H.; Ge, X. T.; Hoo, J.; Yan, L.; Guo, S. P.; Ning, J. Q. et al. Polarity control and nanoscale optical characterization of AlGaN-based multiple-quantum-wells for ultraviolet C emitters. ACS Appl. Nano Mater. 2020, 3, 5335–5342.
Lobo-Ploch, N.; Mehnke, F.; Sulmoni, L.; Cho, H. K.; Guttmann, M.; Glaab, J.; Hilbrich, K.; Wernicke, T.; Einfeldt, S.; Kneissl, M. Milliwatt power 233 nm AlGaN-based deep UV-LEDs on sapphire substrates. Appl. Phys. Lett. 2020, 117, 111102.
Grenier, V.; Finot, S.; Jacopin, G.; Bougerol, C.; Robin, E.; Mollard, N.; Gayral, B.; Monroy, E.; Eymery, J.; Durand, C. UV emission from GaN wires with m-plane core-shell GaN/AlGaN multiple quantum wells. ACS Appl. Mater. Interfaces 2020, 12, 44007–44016.
Knauer, A.; Kolbe, T.; Rass, J.; Cho, H. K.; Netzel, C.; Hagedorn, S.; Lobo-Ploch, N.; Ruschel, J.; Glaab, J.; Einfeldt, S. et al. High power UVB light emitting diodes with optimized n-AlGaN contact layers. Jpn. J. Appl. Phys. 2019, 58, SCCC02.
Pandey, A.; Shin, W. J.; Gim, J.; Hovden, R.; Mi, Z. High-efficiency AlGaN/GaN/AlGaN tunnel junction ultraviolet light-emitting diodes. Photon. Res. 2020, 8, 331–337.
Inagaki, H.; Saito, A.; Sugiyama, H.; Okabayashi, T.; Fujimoto, S. Rapid inactivation of SARS-CoV-2 with deep-UV LED irradiation. Emerging Microbes Infect. 2020, 9, 1744–1747.
Raeiszadeh, M.; Adeli, B. A Critical review on ultraviolet disinfection systems against COVID-19 outbreak: Applicability, validation, and safety considerations. ACS Photonics 2020, 7, 2941–2951.
Schlichting, S.; Hönig, G. M. O.; Müßener, J.; Hille, P.; Grieb, T.; Westerkamp, S.; Teubert, J.; Schörmann, J.; Wagner, M. R.; Rosenauer, A. et al. Suppression of the quantum-confined Stark effect in polar nitride heterostructures. Commun. Phys. 2018, 1, 48.
Guo, W.; Sun, H. D.; Torre, B.; Li, J. M.; Sheikhi, M.; Jiang, J. A.; Li, H. W.; Guo, S. P.; Li, K. H.; Lin, R. H. et al. Lateral-polarity structure of AlGaN quantum wells: A promising approach to enhancing the ultraviolet luminescence. Adv. Funct. Mater. 2018, 28, 1802395.
Simon, J.; Protasenko, V.; Lian, C. X.; Xing, H. L.; Jena, D. Polarization-induced hole doping in wide-band-gap uniaxial semiconductor heterostructures. Science 2010, 327, 60–64.
May, B. J.; Belz, M. R.; Ahamed, A.; Sarwar, A. T. M. G.; Selcu, C. M.; Myers, R. C. Nanoscale electronic conditioning for improvement of nanowire light-emitting-diode efficiency. ACS Nano 2018, 12, 3551–3556.
Kuchuk, A. V.; Lytvyn, P. M.; Li, C.; Stanchu, H. V.; Mazur, Y. I.; Ware, M. E.; Benamara, M.; Ratajczak, R.; Dorogan, V.; Kladko, V. P. et al. Nanoscale electrostructural characterization of compositionally graded AlXGa1−XN heterostructures on GaN/Sapphire (0001) substrate. ACS Appl. Mater. Interfaces 2015, 7, 23320–23327.
Li, S. B.; Ware, M.; Wu, J.; Minor, P.; Wang, Z. M.; Wu, Z. M.; Jiang, Y. D.; Salamo, G. J. Polarization induced pn-junction without dopant in graded AlGaN coherently strained on GaN. Appl. Phys. Lett. 2012, 101, 122103.
Lytvyn, P. M.; Kuchuk, A. V.; Mazur, Y. I.; Li, C.; Ware, M. E.; Wang, Z. M.; Kladko, V. P.; Belyaev, A. E.; Salamo, G. J. Polarization effects in graded AlGaN nanolayers revealed by current-sensing and kelvin probe microscopy. ACS Appl. Mater. Interfaces 2018, 10, 6755–6763.
Stanchu, H.; Der Maur, M. A.; Kuchuk, A. V.; Mazur, Y. I.; Sobanska, M.; Zytkiewicz, Z. R.; Wu, S.; Wang, Z.; Salamo, G. Compositionally graded AlGaN nanostructures: Strain distribution and X-ray diffraction reciprocal space mapping. Cryst. Growth Des. 2020, 20, 1543–1551.
Stanchu, H. V.; Kuchuk, A. V.; Barchuk, M.; Mazur, Y. I.; Kladko, V. P.; Wang, Z. M.; Rafaja, D.; Salamo, G. J. Asymmetrical reciprocal space mapping using X-ray diffraction: A technique for structural characterization of GaN/AlN superlattices. CrystEngComm 2017, 19, 2977–2982.
Kuchuk, A. V.; Stanchu, H. V.; Li, C.; Ware, M. E.; Mazur, Y. I.; Kladko, V. P.; Belyaev, A. E.; Salamo, G. J. Measuring the depth profiles of strain/composition in AlGaN-graded layer by high-resolution X-ray diffraction. J. Appl. Phys. 2014, 116, 224302.
Hetzl, M.; Kraut, M.; Winnerl, J.; Francaviglia, L.; Döblinger, M.; Matich, S.; Morral, A. F. I.; Stutzmann, M. Strain-induced band gap engineering in selectively grown GaN-(Al, Ga)N core-shell nanowire heterostructures. Nano Lett. 2016, 16, 7098–7106.
Okamoto, S.; Saito, N.; Ito, K.; Ma, B.; Morita, K.; Iida, D.; Ohkawa, K.; Ishitani, Y. Energy transport analysis in a Ga0.84In0.16N/GaN heterostructure using microscopic Raman images employing simultaneous coaxial irradiation of two lasers. Appl. Phys. Lett. 2020, 116, 142107.
Qi, M.; Li, G. W.; Protasenko, V.; Zhao, P.; Verma, J.; Song, B.; Ganguly, S.; Zhu, M. D.; Hu, Z. Y.; Yan, X. D. et al. Dual optical marker Raman characterization of strained GaN-channels on AlN using AlN/GaN/AlN quantum wells and 15N isotopes. Appl. Phys. Lett. 2015, 106, 041906.
Liu, E.; Conti, F.; Bhogaraju, S. K.; Signorini, R.; Pedron, D.; Wunderle, B.; Elger, G. Thermomechanical stress in GaN-LEDs soldered onto Cu substrates studied using finite element method and Raman spectroscopy. J. Raman Spectrosc. 2020, 51, 2083–2094.
Ma, B.; Tang, M. C.; Ueno, K.; Kobayashi, A.; Morita, K.; Fujioka, H.; Ishitani, Y. Combined infrared reflectance and Raman spectroscopy analysis of Si-doping limit of GaN. Appl. Phys. Lett. 2020, 117, 192103.
Hammarberg, S.; Dagytė, V.; Chayanun, L.; Hill, M. O.; Wyke, A.; Björling, A.; Johansson, U.; Kalbfleisch, S.; Heurlin, M.; Lauhon, L. J. et al. High resolution strain mapping of a single axially heterostructured nanowire using scanning X-ray diffraction. Nano Res. 2020, 13, 2460–2468.
Sarkar, K.; Datta, D.; Gosztola, D. J.; Shi, F. Y.; Nicholls, A.; Stroscio, M. A.; Dutta, M. Raman analysis of phonon modes in a short period AlN/GaN superlattice. Superlattices Microstruct. 2018, 115, 116–122.
Wallentin, J.; Jacobsson, D.; Osterhoff, M.; Borgström, M. T.; Salditt, T. Bending and twisting lattice tilt in strained core-shell nanowires revealed by nanofocused X-ray diffraction. Nano Lett. 2017, 17, 4143–4150.
Kolomys, O.; Tsykaniuk, B.; Strelchuk, V.; Naumov, A.; Kladko, V.; Mazur, Y. I.; Ware, M. E.; Li, S. B.; Kuchuk, A.; Maidaniuk, Y. et al. Optical and structural study of deformation states in the GaN/AlN superlattices. J. Appl. Phys. 2017, 122, 155302.
Davydov, V. Y.; Averkiev, N. S.; Goncharuk, I. N.; Nelson, D. K.; Nikitina, I. P.; Polkovnikov, A. S.; Smirnov, A. N.; Jacobson, M. A.; Semchinova, O. K. Raman and photoluminescence studies of biaxial strain in GaN epitaxial layers grown on 6H-SiC. J. Appl. Phys. 1997, 82, 5097–5102.
Davydov, V. Y.; Kitaev, Y. E.; Goncharuk, I. N.; Smirnov, A. N.; Graul, J.; Semchinova, O.; Uffmann, D.; Smirnov, M. B.; Mirgorodsky, A. P.; Evarestov, R. A. Phonon dispersion and Raman scattering in hexagonal GaN and AlN. Phys. Rev. B 1998, 58, 12899–12907.
Zhang, L. Full optical phonon states and their dispersive spectra of a wurtzite GaN/AlGaN superlattice: Quantum size effect. Phys. Status Solidi B 2011, 248, 2120–2127.
Park, K.; Mohamed, A.; Dutta, M.; Stroscio, M. A.; Bayram, C. Electron scattering via interface optical phonons with high group velocity in wurtzite GaN-based quantum well heterostructure. Sci. Rep. 2018, 8, 15947.
Darakchieva, V.; Valcheva, E.; Paskov, P. P.; Schubert, M.; Paskova, T.; Monemar, B.; Amano, H.; Akasaki, I. Phonon mode behavior in strained wurtzite AlN∕GaN superlattices. Phys. Rev. B 2005, 71, 115329.
Manjón, F. J.; Errandonea, D.; Romero, A. H.; Garro, N.; Serrano, J.; Kuball, M. Lattice dynamics of wurtzite and rocksalt AlN under high pressure: Effect of compression on the crystal anisotropy of wurtzite-type semiconductors. Phys. Rev. B 2008, 77, 205204.
Sanjurjo, J. A.; López-Cruz, E.; Vogl, P.; Cardona, M. Dependence on volume of the phonon frequencies and the ir effective charges of several III-V semiconductors. Phys. Rev. B 1983, 28, 4579–4584.
Kuball, M.; Hayes, J. M.; Prins, A. D.; Van Uden, N. W. A.; Dunstan, D. J.; Shi, Y.; Edgar, J. H. Raman scattering studies on single-crystalline bulk AlN under high pressures. Appl. Phys. Lett. 2001, 78, 724–726.
Goñi, A. R.; Siegle, H.; Syassen, K.; Thomsen, C.; Wagner, J. M. Effect of pressure on optical phonon modes and transverse effective charges in GaN and AlN. Phys. Rev. B 2001, 64, 035205.
Yakovenko, E. V.; Gauthier, M.; Polian, A. High-pressure behavior of the bond-bending mode of AIN. J. Exp. Theor. Phys. 2004, 98, 981–985.
Perlin, P.; Polian, A.; Suski, T. Raman-scattering studies of aluminum nitride at high pressure. Phys. Rev. B 1993, 47, 2874–2877.
Hibberd, M. T.; Frey, V.; Spencer, B. F.; Mitchell, P. W.; Dawson, P.; Kappers, M. J.; Oliver, R. A.; Humphreys, C. J.; Graham, D. M. Dielectric response of wurtzite gallium nitride in the terahertz frequency range. Solid State Commun. 2016, 247, 68–71.
Yang, S. B.; Miyagawa, R.; Miyake, H.; Hiramatsu, K.; Harima, H. Raman scattering spectroscopy of residual stresses in epitaxial AlN films. Appl. Phys. Express 2011, 4, 031001.
Demangeot, F.; Frandon, J.; Baules, P.; Natali, F.; Semond, F.; Massies, J. Phonon deformation potentials in hexagonal GaN. Phys. Rev. B 2004, 69, 155215.
Davydov, S. Y. Evaluation of physical parameters for the group III nitrates: BN, AlN, GaN, and InN. Semiconductors 2002, 36, 41–44.
Ambacher, O.; Majewski, J.; Miskys, C.; Link, A.; Hermann, M.; Eickhoff, M.; Stutzmann, M.; Bernardini, F.; Fiorentini, V.; Tilak, V. et al. Pyroelectric properties of Al(In)GaN/GaN hetero- and quantum well structures. J. Phys. :Condens. Matter 2002, 14, 3399–3434.
Wagner, J. M.; Bechstedt, F. Properties of strained wurtzite GaN and AlN: Ab initio studies. Phys. Rev. B 2002, 66, 115202.
Sarua, A.; Kuball, M.; Van Nostrand, J. E. Deformation potentials of the E2(high) phonon mode of AlN. Appl. Phys. Lett. 2002, 81, 1426–1428.
Reeber, R. R.; Wang, K. High temperature elastic constant prediction of some group III-nitrides. MRS Internet J. Nitride Semicond. Res. 2001, 6, 3.
Wagner, J. M.; Bechstedt, F. Phonon deformation potentials of α-GaN and -AlN: An ab initio calculation. Appl. Phys. Lett. 2000, 77, 346–348.
Nowak, R.; Pessa, M.; Suganuma, M.; Leszczynski, M.; Grzegory, I.; Porowski, S.; Yoshida, F. Elastic and plastic properties of GaN determined by nano-indentation of bulk crystal. Appl. Phys. Lett. 1999, 75, 2070–2072.
Deguchi, T.; Ichiryu, D.; Toshikawa, K.; Sekiguchi, K.; Sota, T.; Matsuo, R.; Azuhata, T.; Yamaguchi, M.; Yagi, T.; Chichibu, S. et al. Structural and vibrational properties of GaN. J. Appl. Phys. 1999, 86, 1860–1866.
Gleize, J.; Demangeot, F.; Frandon, J.; Renucci, M. A.; Widmann, F.; Daudin, B. Phonons in a strained hexagonal GaN-AlN superlattice. Appl. Phys. Lett. 1999, 74, 703–705.
Shimada, K.; Sota, T.; Suzuki, K. First-principles study on electronic and elastic properties of BN, AlN, and GaN. J. Appl. Phys. 1998, 84, 4951–4958.
Deger, C.; Born, E.; Angerer, H.; Ambacher, O.; Stutzmann, M.; Hornsteiner, J.; Riha, E.; Fischerauer, G. Sound velocity of AlxGa1−xN thin films obtained by surface acoustic-wave measurements. Appl. Phys. Lett. 1998, 72, 2400–2402.
Kim, K.; Lambrecht, W. R. L.; Segall, B. Elastic constants and related properties of tetrahedrally bonded BN, AlN, GaN, and InN. Phys. Rev. B 1996, 53, 16310–16326.
Wright, A. F. Elastic properties of zinc-blende and wurtzite AlN, GaN, and InN. J. Appl. Phys. 1997, 82, 2833–2839.
Yamaguchi, M.; Yagi, T.; Azuhata, T.; Sota, T.; Suzuki, K.; Chichibu, S.; Nakamura, S. Brillouin scattering study of gallium nitride: Elastic stiffness constants. J. Phys. :Condens. Matter 1997, 9, 241–248.
Schwarz, R. B.; Khachaturyan, K.; Weber, E. R. Elastic moduli of gallium nitride. Appl. Phys. Lett. 1997, 70, 1122–1124.
Polian, A.; Grimsditch, M.; Grzegory, I. Elastic constants of gallium nitride. J. Appl. Phys. 1996, 79, 3343–3344.
Kim, K.; Lambrecht, W. R. L.; Segall, B. Electronic structure of GaN with strain and phonon distortions. Phys. Rev. B 1994, 50, 1502–1505.
Kato, R.; Hama, J. First-principles calculation of the elastic stiffness tensor of aluminium nitride under high pressure. J. Phys. :Condens. Matter 1994, 6, 7617–7632.
Ruiz, E.; Alvarez, S.; Alemany, P. Electronic structure and properties of AlN. Phys. Rev. B 1994, 49, 7115–7123.
McNeil, L. E.; Grimsditch, M.; French, R. H. Vibrational spectroscopy of aluminum nitride. J. Am. Ceram. Soc. 1993, 76, 1132–1136.
Tsubouchi, K.; Mikoshiba, N. Zero-temperature-coefficient SAW devices on AlN epitaxial films. IEEE Trans. Sonics Ultrason. 1985, 32, 634–644.
Savastenko, V. A.; Sheleg, A. U. Study of the elastic properties of gallium nitride. Phys. Status Solidi A 1978, 48, K135–K139.
Shen, X. Q.; Takahashi, T.; Ide, T.; Shimizu, M. Mechanisms of the micro-crack generation in an ultra-thin AlN/GaN superlattice structure grown on Si(110) substrates by metalorganic chemical vapor deposition. J. Appl. Phys. 2015, 118, 125307.
Einfeldt, S.; Heinke, H.; Kirchner, V.; Hommel, D. Strain relaxation in AlGaN/GaN superlattices grown on GaN. J. Appl. Phys. 2001, 89, 2160–2167.
Tripathy, S.; Chua, S. J.; Chen, P.; Miao, Z. L. Micro-Raman investigation of strain in GaN and AlxGa1−xN/GaN heterostructures grown on Si(111). J. Appl. Phys. 2002, 92, 3503–3510.
Ramkumar, C.; Prokofyeva, T.; Seon, M.; Holtz, M.; Choi, K.; Yun, J.; Nikishin, S. A.; Temkin, H. Micro-Raman scattering from hexagonal GaN, AlN, and AlxGa1−x}N grown on (111) oriented silicon: Stress mapping of cracks. MRS Online Proc. Libr. 2001, 693, 39–43.
Agrawal, M.; Dharmarasu, N.; Radhakrishnan, K.; Ravikiran, L. Structural properties of GaN grown on AlGaN/AlN stress mitigating layers on 100-mm Si (111) by ammonia molecular beam epitaxy. Thin Solid Films 2012, 520, 7109–7114.
Lee, H. P.; Perozek, J.; Rosario, L. D.; Bayram, C. Investigation of AlGaN/GaN high electron mobility transistor structures on 200-mm silicon (111) substrates employing different buffer layer configurations. Sci. Rep. 2016, 6, 37588.
Christy, D.; Watanabe, A.; Egawa, T. Influence of strain induced by AlN nucleation layer on the electrical properties of AlGaN/GaN heterostructures on Si(111) substrate. AIP Adv. 2014, 4, 107104.
Bansal, A.; Wang, K.; Lundh, J. S.; Choi, S.; Redwing, J. M. Effect of Ge doping on growth stress and conductivity in AlxGa1−xN. Appl. Phys. Lett. 2019, 114, 142101.
Amano, H.; Baines, Y.; Beam, E.; Borga, M.; Bouchet, T.; Chalker, P. R.; Charles, M.; Chen, K. J.; Chowdhury, N.; Chu, R. M. et al. The 2018 GaN power electronics roadmap. J. Phys. D: Appl. Phys. 2018, 51, 163001.
Sun, H. D.; Mitra, S.; Subedi, R. C.; Zhang, Y.; Guo, W.; Ye, J. C.; Shakfa, M. K.; Ng, T. K.; Ooi, B. S.; Roqan, I. S. et al. Unambiguously enhanced ultraviolet luminescence of AlGaN wavy quantum well structures grown on large misoriented sapphire substrate. Adv. Funct. Mater. 2019, 29, 1905445.
Huang, C.; Zhang, H. C.; Sun, H. D. Ultraviolet optoelectronic devices based on AlGaN-SiC platform: Towards monolithic photonics integration system. Nano Energy 2020, 77, 105149.
Zhang, H. C.; Huang, C.; Song, K.; Yu, H. B.; Xing, C.; Wang, D. H.; Liu, Z. L.; Sun, H. D. Compositionally graded III-nitride alloys: Building blocks for efficient ultraviolet optoelectronics and power electronics. Rep. Prog. Phys. 2021, 84, 044401.
Publication history
Copyright
Acknowledgements
This work was supported by the U.S. National Science Foundation Engineering Research Center for Power Optimization of Electro Thermal Systems (POETS) with cooperative agreement EEC-1449548. F. M. O. and M. D. T. acknowledge the financial support of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.
FEEDBACK 
TOP