Dependence of radiative and nonradiative recombination on carrier density and Al content in thick AlGaN epilayers

Podlipskas, Žydrūnas; Aleksiejūnas, R.; Kadys, A.; Mickevičius, J.; Jurkevičius, Jonas; Тамулайтис, Г.; Shur, M. S.; Shatalov, M.; Yang, Jinwei; Gaška, R.

doi:10.1088/0022-3727/49/14/145110

Cited by 21 publications

(20 citation statements)

References 28 publications

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“…Peak carrier lifetime decreases from 0.9 to 0.4 ns in the AlGaN barriers with increasing Al content (from 0.13 to 0.34; see Fig. 2); this result is consistent with the previously reported trend in AlGaN epilayers with wide Al composition range 29 . Evidently, the optimization of growth conditions does not compensate for the decrease in structural quality with growing Al content.…”

Section: Resultssupporting

confidence: 92%

The detrimental effect of AlGaN barrier quality on carrier dynamics in AlGaN/GaN interface

Podlipskas

Jurkevičius

Kadys

et al. 2019

Sci Rep

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Carrier recombination and scattering at the semiconductor boundaries can substantially limit the device efficiency. However, surface and interface recombination is generally neglected in the nitride-based devices. Here, we study carrier recombination and diffusivity in AlGaN/GaN/sapphire heterointerfaces with AlGaN barriers of different quality. We employ the light induced transient grating and time-resolved photoluminescence spectroscopy techniques to extract carrier lifetime in different depths of the GaN buffer as well as in the AlGaN barrier, and to evaluate the carrier diffusion coefficient in the buffer. Moreover, we assess interface recombination velocity, Shockley-Read-Hall and radiative recombination rates. We reveal the adverse barrier influence on carrier dynamics in the underlying buffer: AlGaN barrier accelerates the nonradiative carrier recombination in the GaN buffer. The interface recombination velocity in the GaN buffer increases with decreasing AlGaN barrier quality, and the dominating recombination mechanism switches from Shockley-Read-Hall to interface recombination. These phenomena are governed by a cumulative effect of various interface-deteriorating barrier defects. Meanwhile, the carrier diffusivity in the GaN buffer is not affected by the AlGaN barrier. We conclude that barrier-accelerated interface recombination can become a major carrier loss mechanism in AlGaN/GaN interface, and may substantially limit the efficiency in nitride-based UV LEDs.

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Section: Resultssupporting

confidence: 92%

The detrimental effect of AlGaN barrier quality on carrier dynamics in AlGaN/GaN interface

Podlipskas

Jurkevičius

Kadys

et al. 2019

Sci Rep

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“…to be %8.0 Â 10 À11 cm 3 s À1 . [41,42] Using this B value, the best fitting gives A ¼ 5.8 Â 10 8 s À1 and C ¼ 3.1 Â 10 À30 cm 6 s À1 . The calculated IQE as a function of n is shown in Figure 3.…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the large C coefficient might be attributed to carrier delocalization, Auger recombination, and other effects. [41,42] To examine if there is any light amplification of the AlGaN/ AlN DH, the as-grown wafer was further pumped by the 266 nm laser. The solid and dashed curves in Figure 4a represent the transverse-electric (TE)-and transverse-magnetic (TM)-polarized light emission spectra, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Recent comparative studies on the recombination coefficients between the thick AlGaN epilayers and QWs suggest an Al‐content‐dependent B coefficient; and for thick AlGaN epilayers emitting at around 295 nm, the B coefficient is suggested to be ≈8.0 × 10 −11 cm 3 s −1 . [ 41,42 ] Using this B value, the best fitting gives A = 5.8 × 10 8 s −1 and C = 3.1 × 10 −30 cm 6 s −1 . The calculated IQE as a function of n is shown in Figure 3 .…”

Section: Resultsmentioning

confidence: 99%

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Optical Quality and Stimulated Emission of Molecular Beam Epitaxy Grown AlGaN in the Deep Ultraviolet

Yin

Zhao

2020

Physica Status Solidi (b)

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In this work, the optical quality and stimulated emission of aluminum gallium nitride (AlGaN)/AlN double heterostructure grown by molecular beam epitaxy in the deep ultraviolet (UV) are reported. The room temperature internal quantum efficiency at a carrier density of 1 × 1018 cm−3 is around 12%, mainly limited by dislocations. For such as‐grown wafers, spectral narrowing and nonlinearity of the light output are measured from the wafer edge, with the transverse‐electric (TE)‐polarized component becoming dominant as the excitation increases. With cleaving, edge‐emitting lasing at 298 nm is measured, with an estimated threshold of 0.95 MW cm−2.

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“…However, the formation of extended and point defects during growth and fabrication of AlGaN based devices is unavoidable. This leads to the appearance of ultraviolet (UV) photo-luminescence peaks which are shifted to the short-wavelength range with increase of Al content within this ternary material [4]. The radiation defects are formed in detector structures during operation at extreme fluence conditions which can modify optical and electrical characteristics.…”

Section: Introductionmentioning

confidence: 99%

Evolution of Scintillation and Electrical Characteristics of AlGaN Double-Response Sensors During Proton Irradiation

Čeponis

Badokas

Deveikis

et al. 2019

Sensors

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Wide bandgap AlGaN is one of the most promising materials for the fabrication of radiation hard, double-response particle detectors for future collider facilities. However, the formation of defects during growth and fabrication of AlGaN-based devices is unavoidable. Furthermore, radiation defects are formed in detector structures during operation at extreme conditions. In this work, study of evolution of the proton-induced luminescence spectra and short-circuit current has been simultaneously performed during 1.6 MeV proton irradiation. GaN and AlGaN (with various Al concentrations) epi-layers grown by metalorganic chemical vapour deposition technique and Schottky diode structures have been examined. Variations of spectral and electrical parameters could be applied for the remote dosimetry of large hadron fluences.

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Dependence of radiative and nonradiative recombination on carrier density and Al content in thick AlGaN epilayers

Cited by 21 publications

References 28 publications

The detrimental effect of AlGaN barrier quality on carrier dynamics in AlGaN/GaN interface

The detrimental effect of AlGaN barrier quality on carrier dynamics in AlGaN/GaN interface

Optical Quality and Stimulated Emission of Molecular Beam Epitaxy Grown AlGaN in the Deep Ultraviolet

Evolution of Scintillation and Electrical Characteristics of AlGaN Double-Response Sensors During Proton Irradiation

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