Band parameters and strain effects in ZnO and group-III nitrides

Yan, Qimin; Rinke, Patrick; Winkelnkemper, Momme; Qteish, A.; Bimberg, D.; Scheffler, Matthias; Walle, Chris G. Van de

doi:10.1088/0268-1242/26/1/014037

Cited by 66 publications

(50 citation statements)

References 97 publications

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“…We also note an energy splitting between the two lowest exciton transitions for the two polarizations of the excitation light of 35 meV. We attribute this splitting mainly to the crystal field splitting energy in the (In,Ga)N system [43].…”

Section: B Experimental Results: Optical Characterizationmentioning

confidence: 65%

“…First, assuming growth along the y direction, the QW confinement lifts the degeneracy of the |X -and |Y -like valence band states due to their different effective masses along the growth direction [14,19,22]. Second, |X -and |Z -like states are energetically separated by the crystal field splitting energy in (In,Ga)N alloys [43]. Thus, the VBE is expected to be predominately |X -like.…”

Section: B Experimental Results: Optical Characterizationmentioning

confidence: 99%

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Structural, electronic, and optical properties ofm-plane InGaN/GaN quantum wells: Insights from experiment and atomistic theory

Schulz¹,

Tanner

O’Reilly

et al. 2015

Phys. Rev. B

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In this paper we present a detailed analysis of the structural, electronic, and optical properties of an m-plane (In,Ga)N/GaN quantum well structure grown by metal organic vapor phase epitaxy. The sample has been structurally characterized by x-ray diffraction, scanning transmission electron microscopy, and 3D atom probe tomography. The optical properties of the sample have been studied by photoluminescence (PL), time-resolved PL spectroscopy, and polarized PL excitation spectroscopy. The PL spectrum consisted of a very broad PL line with a high degree of optical linear polarization. To understand the optical properties we have performed atomistic tight-binding calculations, and based on our initial atom probe tomography data, the model includes the effects of strain and built-in field variations arising from random alloy fluctuations. Furthermore, we included Coulomb effects in the calculations. Our microscopic theoretical description reveals strong hole wave function localization effects due to random alloy fluctuations, resulting in strong variations in ground state energies and consequently the corresponding transition energies. This is consistent with the experimentally observed broad PL peak. Furthermore, when including Coulomb contributions in the calculations we find strong exciton localization effects which explain the form of the PL decay transients. Additionally, the theoretical results confirm the experimentally observed high degree of optical linear polarization. Overall, the theoretical data are in very good agreement with the experimental findings, highlighting the strong impact of the microscopic alloy structure on the optoelectronic properties of these systems.

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Section: B Experimental Results: Optical Characterizationmentioning

confidence: 65%

Section: B Experimental Results: Optical Characterizationmentioning

confidence: 99%

Structural, electronic, and optical properties ofm-plane InGaN/GaN quantum wells: Insights from experiment and atomistic theory

Schulz¹,

Tanner

O’Reilly

et al. 2015

Phys. Rev. B

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“…Bulk ZnO have a direct band gap of 3.37 eV (at bulk state) and a larger exciton binding energy (60 meV). The electronic band gap of ZnO has been predicted theoretically and calculated by many people (Oshikiri and Aryasetiawan 2000;Muscat et al 2001;Usuda and Hamada 2002;Uddin and Scuseria 2006;Shishkin and Kresse 2007;Christoph Friedrich et al 2011;Dixit et al 2011;Yan et al 2011), and lot of experimental work have been done to find out the band gap of ZnO (varying 2.9-3.7 eV) (Alhamed and Abdullah 2010;Ma et al 2011;Sakthivelu et al 2011;Zandi et al 2011;Tan et al 2005;Bandyopadhyay et al 2002;Inamdar et al 2007;Ananthakumar et al 2010). ZnO is very useful in several opto-electronic field such as optical sensors and light emitters (RF Service 1997; Makino et al 2000), etc.…”

Section: Introductionmentioning

confidence: 99%

“…There are many methods to synthesize ZnO nanomaterial such as, preparation by sputtering (Yan et al 2011), chemical vapor deposition (Park et al 2006), molecular beam epitaxy (MBE) (Fons et al 2006), spry pyrolysis (Joseph et al 1999), laser deposition , and the soft chemical method (Ristic et al 2005;Kuo et al 2006). Alhamed and Abdullah (2010) has discussed structural and optical properties of ZnO:Al films prepared by the sol-gel method.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ZnO/Al:ZnO nanomaterial: structural and band gap variation in ZnO nanomaterial by Al doping

et al. 2012

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Pure ZnO and Al-doped ZnO nanomaterial have been successfully fabricated using zinc acetate dihydrate in a basic aqueous solution of KOH through solution precipitation method then treated at 600°C in air. The XRD analysis confirms the Wurtzite hexagonal crystal structure of the product with crystallite size in 32-53 nm range. The morphology of the product has been studied under scanning electron microscopy (SEM). The simultaneous differential scanning calorimetry and thermogravimetric analyses were used to investigate thermal decomposition temperature and different phase transitions up to 800°C. The optical properties and variation in band gap of ZnO by Al doping were investigated by ultraviolet-visible spectroscopy.

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“…This model provides a realistic description of the bulk bandstructure throughout the full Brillouin zone using the sp 3 -basis and hopping matrix elements up to second nearest neighbors. Recent G 0 W 0 data 16,18 serve as input for the parametrization scheme of the bulk matrix elements. The weak spin-orbit splitting of about 5 meV for InN (Ref.…”

mentioning

confidence: 99%

Strong dipole coupling in nonpolar nitride quantum dots due to Coulomb effects

Schuh

Barthel

Marquardt

et al. 2012

Applied Physics Letters

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Optical properties of polar and nonpolar nitride quantum dots (QDs) are determined on the basis of a microscopic theory which combines a continuum elasticity approach to the polarization potential, a tight-binding model for the electronic energies and wavefunctions, and a many-body theory for the optical properties. For nonpolar nitride quantum dots, we find that optical absorption and emission spectra exhibit a weak ground-state oscillator strength in a single-particle calculation whereas the Coulomb configuration interaction strongly enhances the ground-state transitions. This finding sheds new light on existing discrepancies between previous theoretical and experimental results for these systems, as a weak ground state transition was predicted because of the spatial separation of the corresponding electron and hole state due to intrinsic fields whereas experimentally fast optical transitions have been observed.

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Band parameters and strain effects in ZnO and group-III nitrides

Cited by 66 publications

References 97 publications

Structural, electronic, and optical properties ofm-plane InGaN/GaN quantum wells: Insights from experiment and atomistic theory

Structural, electronic, and optical properties ofm-plane InGaN/GaN quantum wells: Insights from experiment and atomistic theory

Synthesis of ZnO/Al:ZnO nanomaterial: structural and band gap variation in ZnO nanomaterial by Al doping

Strong dipole coupling in nonpolar nitride quantum dots due to Coulomb effects

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