Stacking Faults as Quantum Wells for Excitons in Wurtzite GaN

Rebane, Yu. T.; Shreter, Yu. G.; Albrecht, M.

doi:10.1002/1521-396x(199711)164:1<141::aid-pssa141>3.0.co;2-g

Cited by 109 publications

(88 citation statements)

References 8 publications

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“…These BSFs are commonly considered as quantum wells made of zinc-blende-like material surrounded by the wurtzite matrix, giving rise to a luminescence line at lower energy than the excitonic gap of wurtzite GaN. 7 Density functional pseudopotential calculations 10 and another model based on elastic deformation potentials 11 both suggest that the valence-and conduction-band offsets between wurtzite and zinc blende should generate a shallow and thin type-II quantum well ͓⌬E C = 122 meV, ⌬E V = −62 meV, and L = 0.77 nm ͑Ref. 7͔͒, where electrons are only confined within the I 1 BSF.…”

Section: CL Of Basal-plane Stacking Faultsmentioning

confidence: 91%

“…The single energy levels of each quantum well would thus be split into many levels organized in minibands due to the overlap of the wave functions. Using the electron wave function calculated by Rebane et al, 11 we find a penetration length of the electron wave function inside the hexagonal phase of ϳ3 nm, a value compatible with quantum coupling between two BSFs as their average separation distance in both the window and the −c wings can be estimated as 10 nm. 14 The temporal evolution of PL spectra brings additional insight into localization effects inside the BSFs ͑Fig.…”

Section: Localization Effectsmentioning

confidence: 95%

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Exciton localization on basal stacking faults in a-plane epitaxial lateral overgrown GaN grown by hydride vapor phase epitaxy

Corfdir

Lefèbvre

Levrat

et al. 2009

Journal of Applied Physics

104

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We present a detailed study of the luminescence at 3.42 eV usually observed in a-plane epitaxial lateral overgrowth ͑ELO͒ GaN grown by hydride vapor phase epitaxy on r-plane sapphire. This band is related to radiative recombination of excitons in a commonly encountered extended defect of a-plane GaN: I 1 basal stacking fault. Cathodoluminescence measurements show that these stacking faults are essentially located in the windows and the N-face wings of the ELO-GaN and that they can appear isolated as well as organized into bundles. Time-integrated and time-resolved photoluminescence, supported by a qualitative model, evidence not only the efficient trapping of free excitons ͑FXs͒ by basal plane stacking faults but also some localization inside I 1 stacking faults themselves. Measurements at room temperature show that FXs recombine efficiently with rather long luminescence decay times ͑360 ps͒, comparable to those encountered in high-quality GaN epilayers. We discuss the possible role of I 1 stacking faults in the overall recombination mechanism of excitons.

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Section: CL Of Basal-plane Stacking Faultsmentioning

confidence: 91%

Section: Localization Effectsmentioning

confidence: 95%

Exciton localization on basal stacking faults in a-plane epitaxial lateral overgrown GaN grown by hydride vapor phase epitaxy

Corfdir

Lefèbvre

Levrat

et al. 2009

Journal of Applied Physics

104

View full text Add to dashboard Cite

show abstract

“…Such a structure forms a type-II heterojunction which may capture electrons and holes resulting in optical transitions below the wurtzite GaN bandgap energy. [9][10][11] More recently, a BSF related emission from aplane GaN/AlGaN quantum well (QW) structures was reported, suggesting the formation of quantum-wire-like states in the regions where BSFs intersect the QWs. 12,13 In this paper, we investigate the optical properties of m-plane GaInN/GaN QW structures grown on silicon carbide (SiC).…”

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confidence: 99%

Highly efficient light emission from stacking faults intersecting nonpolar GaInN quantum wells

Jönen

Rossów

Bremers

et al. 2011

Applied Physics Letters

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We report on the optical properties of m-plane GaInN/GaN quantum wells (QWs). We found that the emission energy of GaInN QWs grown on m-plane SiC is significantly lower than on nonpolar bulk GaN, which we attribute to the high density of stacking faults. Temperature and power dependent photoluminescence reveals that the GaInN QWs on SiC have almost as large internal quantum efficiencies as on bulk GaN despite the much higher defect density. Our results indicate that quantum-wire-like features formed by stacking faults intersecting the quantum wells provide a highly efficient light emission completely dominating the optical properties of the structures. V C 2011 American Institute of Physics. [doi:10.1063/1.3607301] In the past few years, GaN-based light emitting devices grown on non-polar planes have continuously attracted increasing attention due to their promising optical properties. While conventional structures grown on the polar c-plane suffer from the quantum-confined Stark effect (QCSE), 1 GaN layers grown on non-polar surfaces are free from polarization fields in growth direction. 2 The increased transition probability may result in an improved device efficiency leading to increased light output powers and/or reduced threshold current densities. 3 Indeed, the first GaInN based laser diodes with an emission wavelength at 500 nm have been shown by Okamoto et al. on m-plane GaN substrates. 4 However, up to now, non-polar GaN substrates are still barely available, small in size, and also very expensive. As an alternative, several groups have reported heteroepitaxial growth of non-polar GaN layers on foreign substrates (c-LiAlO 2 , SiC, r-plane sapphire). [5][6][7] However, most of these structures were affected by high densities of threading dislocations (TDs) and basal plane stacking faults (BSFs), which are terminated by either prismatic stacking faults (PSFs) or partial dislocations. 8 While TDs are known to act as nonradiative recombination centers, BSFs are optically active since they can be considered as cubic (zincblende) ABC phases in the wurtzite ABAB stacking sequence. Such a structure forms a type-II heterojunction which may capture electrons and holes resulting in optical transitions below the wurtzite GaN bandgap energy. 9-11 More recently, a BSF related emission from aplane GaN/AlGaN quantum well (QW) structures was reported, suggesting the formation of quantum-wire-like states in the regions where BSFs intersect the QWs. 12,13 In this paper, we investigate the optical properties of m-plane GaInN/GaN QW structures grown on silicon carbide (SiC). In particular, we show that stacking faults intersecting the QWs dominate the optical properties of these structures.Our samples were grown on m-plane 6H-SiC, m-plane bulk GaN substrates, and a-plane GaN templates (grown by hydride vapor phase epitaxy) in a low pressure metalorganic vapor phase epitaxy system with a horizontal reactor (Aixtron AIX 200RF). The precursors used were trimethylgallium, triethylgallium, trimethylaluminum, trimethylindium,...

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“…A peak often observed at 3.40-3.42 eV has been attributed to an exciton bound to a stacking fault. 24 A high density of stacking faults might indeed be expected for wurtzite GaN grown on a cubic template.…”

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confidence: 99%