Correlation between temperature dependence of Raman shifts and in-plane strains in an AlGaN/GaN stack

Kosemura, Daisuke; Sodan, Vice; Wolf, Ingrid De

doi:10.1063/1.4974366

Cited by 10 publications

(11 citation statements)

References 48 publications

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“…21 There was no phonon mode associated with the cubic phase of AlGaN and GaN, indicating that our samples had a hexagonal structure. Internal strain due to a latice mismatch causes the peak shifting, as revealed by Zardo et al 22 and Kosemura et al 23 The results indicate that the p-GaN/AlGaN/GaN heterostructure was grown epitaxially on the Si(111) substrate.…”

Section: Device Fabrication and Experimental Setupmentioning

confidence: 82%

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Giant Piezotronic Effect by Photoexcitation–Electronic Coupling in a p-GaN/AlGaN/GaN Heterojunction

Nguyen

Foisal

Tanner

et al. 2022

ACS Appl. Electron. Mater.

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The incorporation of multiphysics stimuli with traditional sensing effects results in an approach for increasing the sensitivity of mechanical sensors, in particular strain sensing. This paper reports on the giant piezotronic effect in a p-GaN/AlGaN/GaN heterojunction coupled with UV illumination and tuning current that can reach a strain sensitivity of as high as 70680. In comparison to an identical configuration without coupling, this value represents a 100-fold improvement. This sensitivity is one of the greatest for the piezotronic effect in semiconductors that have been documented to date. The intensification of the piezotronic effect in the p-GaN/AlGaN/GaN heterojunctions was ascribed to the formation of a carrier concentration gradient in the AlGaN and GaN layers under UV illumination coupled with the potential-balancing effect by a tuning current. In addition, the result showed a significant improvement in repeatability, stability, and detectable range of the strain sensor utilizing this phenomenon. The ultrahigh sensitivity strain sensing technique will open the way for the establishment of mechanical sensors that are tremendously sensitive, trustworthy, and efficient.

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Section: Device Fabrication and Experimental Setupmentioning

confidence: 82%

“…Internal strain due to a latice mismatch causes the peak shifting, as revealed by Zardo et al . and Kosemura et al The results indicate that the p-GaN/AlGaN/GaN heterostructure was grown epitaxially on the Si(111) substrate.…”

Section: Device Fabrication and Experimental Setupmentioning

confidence: 82%

Giant Piezotronic Effect by Photoexcitation–Electronic Coupling in a p-GaN/AlGaN/GaN Heterojunction

Nguyen

Foisal

Tanner

et al. 2022

ACS Appl. Electron. Mater.

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“…The typical Raman peak of the Si substrate was observed at 521 cm −1 in the B-PD structure and the separated Si substrate, but it was not observed in the M-PD structure. In the B-PD structure, the Raman peaks 23 were measured at 521 cm −1 for the Si substrate, 570 cm −1 for the GaN layer, and 736 cm −1 for the Al 0.12 GaN layer, respectively, as shown in Figure 4a. After the lift-off process, the GaN and AlGaN Raman peaks were observed in the lift-off M-PD structure without the Si peak.…”

Section: Resultsmentioning

confidence: 99%

Characterizations of AlGaN/GaN Membrane-type Photodetectors

Chou

Wang

et al. 2022

ACS Appl. Opt. Mater.

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Al0.12GaN/GaN membrane-type photodetectors (M-PD) were separated from the Si substrates through a chemical lift-off process. High photocurrent, low dark current, and high responsivity properties were observed in the M-PD structure compared to that on the Si substrate. Lattice-mismatch-induced tensile strain on the Al0.12GaN layer was enlarged in the M-PD structure and was analyzed by the photoluminescence and Raman spectra. From the simulation results, the energy band bending induced the potential barrier height at the AlN/air separated surface to deplete the surface states and suppress the leakage current. The strain in the AlGaN/GaN structures was manipulated by removing the Si substrate and roughening the AlN surface. The membrane-type ultraviolet photodetector consisted of the AlGaN/GaN two-dimensional electron gas channel and the large tensile strain at the Al0.12GaN layer, which can be used for high-efficiency optoelectronic applications.

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“…There were both AlN‐like peaks and GaN‐like peaks in the Raman spectra from AlGaN. [ 22,23 ] The energy of these two phonon modes is dependent on both the Al composition and the strain of the AlGaN layer. As shown in the published reports, [ 2,24 ] the Al composition dependency of AlN‐like E 2 (high) mode energy is about 0.20 cm −1 /(0.1x), where x is the Al composition in Al x Ga (1−x) N. This is much smaller than the Al composition dependency of the GaN‐like E 2 (high) mode of 6.8 cm −1 /(0.1x), while the Raman shift due to the strain variation in GaN‐LED structures is ~1 cm −1 .…”

Section: Resultsmentioning

confidence: 99%

Depth‐dependent strain distribution in AlGaN‐based deep ultraviolet light‐emitting diodes using surface‐plasmon‐enhanced Raman spectroscopy

Jung

Kim

et al. 2021

J Raman Spectroscopy

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Ex situ depth-dependent strain distribution in AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) was investigated through surfaceplasmon-enhanced Raman spectroscopy with an optimally truncated structure.In this study, the strain was selectively analyzed by an ex situ method as a function of the distance from the sapphire substrate followed by AlN relaxation layers. Experimental results for DUV LEDs with a complex structure showed that the strain was non-uniformly distributed with the thickness and that the compressive strain tended to gradually decrease when the AlGaN layer or the AlN relaxation layer was grown from the substrate. We quantitatively determined the subtle changes in the additional strain caused by the lattice mismatch between the underlying layers subjected to the residual compressive strain.

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Correlation between temperature dependence of Raman shifts and in-plane strains in an AlGaN/GaN stack

Cited by 10 publications

References 48 publications

Giant Piezotronic Effect by Photoexcitation–Electronic Coupling in a p-GaN/AlGaN/GaN Heterojunction

Giant Piezotronic Effect by Photoexcitation–Electronic Coupling in a p-GaN/AlGaN/GaN Heterojunction

Characterizations of AlGaN/GaN Membrane-type Photodetectors

Depth‐dependent strain distribution in AlGaN‐based deep ultraviolet light‐emitting diodes using surface‐plasmon‐enhanced Raman spectroscopy

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