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Lin, Tai‐Yuan; Chen, H. M.; Tsai, Ming-Sheu; Chen, Y. F.; Fang, F. F.; Lin, Cheng‐Chung; C., G.

doi:10.1103/physrevb.58.13793

Cited by 30 publications

(15 citation statements)

References 30 publications

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“…Such PPC behavior has been observed in many III-V and II-VI semiconductor thin films and heterostructures. [19][20][21][22][23][24][25][26]28,[30][31][32][38][39][40][41] The origin of the PPC can be explained by the fact that the photoexcited carriers are trapped and spatially separated by local potential fluctuations, which then suppresses the recombination of carriers. The Al content affects the PPC decay rate.…”

Section: Resultsmentioning

confidence: 99%

“…The other deep-level donors in the heterostructures are able to produce a PPC effect as long as the deep donor level is below the Fermi energy. 21,30 In the GaN and Al x Ga 1−x N epilayers, this was similarly ascribed to defect complexes such as gallium vacancies, nitrogen antisites, deep-level impurities, and interacting defect complexes. 19,20,28,29,[31][32][33][34] In the literature, several studies can be found about PPC experiments on Al x Ga 1−x N / GaN heterostructures.…”

Section: Introductionmentioning

confidence: 99%

“…29 This results in a persistent carrier concentration, which can be used to obtain a PPC under an applied voltage bias. 30 The PPC effect in Al x Ga 1−x As is induced by the metastable DX centers. 29 However, in the heterostructure and quantum well structures, the PPC effect is no longer limited to the presence of DX centers.…”

Section: Introductionmentioning

confidence: 99%

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The persistent photoconductivity effect in AlGaN/GaN heterostructures grown on sapphire and SiC substrates

Arslan

Bütün

Li̇şesi̇vdi̇n

et al. 2008

Journal of Applied Physics

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In the present study, we reported the results of the investigation of electrical and optical measurements in Al x Ga 1−x N / GaN heterostructures ͑x = 0.20͒ that were grown by way of metal-organic chemical vapor deposition on sapphire and SiC substrates with the same buffer structures and similar conditions. We investigated the substrate material effects on the electrical and optical properties of Al 0.20 Ga 0.80 N / GaN heterostructures. The related electrical and optical properties of Al x Ga 1−x N / GaN heterostructures were investigated by variable-temperature Hall effect measurements, photoluminescence ͑PL͒, photocurrent, and persistent photoconductivity ͑PPC͒ that in turn illuminated the samples with a blue ͑ = 470 nm͒ light-emitting diode ͑LED͒ and thereby induced a persistent increase in the carrier density and two-dimensional electron gas ͑2DEG͒ electron mobility. In sample A ͑Al 0.20 Ga 0.80 N / GaN/ sapphire͒, the carrier density increased from 7.59ϫ 10 12 to 9.9ϫ 10 12 cm −2 via illumination at 30 K. On the other hand, in sample B ͑Al 0.20 Ga 0.80 N / GaN/ SiC͒, the increments in the carrier density were larger than those in sample A, in which it increased from 7.62ϫ 10 12 to 1.23ϫ 10 13 cm −2 at the same temperature. The 2DEG mobility increased from 1.22ϫ 10 4 to 1.37ϫ 10 4 cm −2 / V s for samples A and B, in which 2DEG mobility increments occurred from 3.83ϫ 10 3 to 5.47ϫ 10 3 cm −2 / V s at 30 K. The PL results show that the samples possessed a strong near-band-edge exciton luminescence line at around 3.44 and 3.43 eV for samples A and B, respectively. The samples showed a broad yellow band spreading from 1.80 to 2.60 eV with a peak maximum at 2.25 eV with a ratio of a near-band-edge excitation peak intensity up to a deep-level emission peak intensity ratio that were equal to 3 and 1.8 for samples A and B, respectively. Both of the samples that were illuminated with three different energy photon PPC decay behaviors can be well described by a stretched-exponential function and relaxation time constant as well as a decay exponent ␤ that changes with the substrate type. The energy barrier for the capture of electrons in the 2DEG channel via the deep-level impurities ͑DX-like centers͒ in AlGaN for the Al 0.20 Ga 0.80 N / GaN/sapphire and Al 0.20 Ga 0.80 N / GaN/ SiC heterojunction samples are 343 and 228 meV, respectively. The activation energy for the thermal capture of an electron by the defects ⌬E changed with the substrate materials. Our results show that the substrate material strongly affects the electrical and optical properties of Al 0.20 Ga 0.80 N/GaN heterostructures. These results can be explained with the differing degrees of the lattice mismatch between the grown layers and substrates.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The persistent photoconductivity effect in AlGaN/GaN heterostructures grown on sapphire and SiC substrates

Arslan

Bütün

Li̇şesi̇vdi̇n

et al. 2008

Journal of Applied Physics

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“…On leave from Institute of Semiconductor Physics, NASU, 03028 Kiev, Ukraine. JOURNAL OF APPLIED PHYSICS 105, 073703 ͑2009͒ resonance [14][15][16] and magnetotransport [17][18][19] results͒ that the inplane effective mass can exceed the bulk values considerably due to the increasing effect of conduction band nonparabolicity at higher Fermi energy. At the same time, even taking into account this effect, a large scatter of the data is not well understood and uncertainty of the effective mass in 2DEG with different carrier density and spatial confinement is large.…”

Section: Introductionmentioning

confidence: 99%

“…Even in high-quality AlGaN/GaN heterostructures, the in-plane effective mass of 2D electrons measured by various direct and indirect techniques has shown effective mass enhancement and a large scatter of the data [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] ͑Fig. 1͒.…”

Section: Introductionmentioning

confidence: 99%

Quantum confinement effect on the effective mass in two-dimensional electron gas of AlGaN/GaN heterostructures

Kurakin

Vitusevich

Danylyuk

et al. 2009

Journal of Applied Physics

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We report the results of direct measurements and a theoretical investigation of the in-plane effective mass in the two-dimensional electron gas of nominally undoped AlGaN/GaN heterostructures with a different degree of quantum confinement. It is shown that in most cases the conduction band nonparabolicity effect is overestimated and the electron wave-function penetration into the barrier layer should be taken into account. The contribution of the wave-function hybridization is determined to play the dominant role. The band edge effective mass value is deduced to be (0.2±0.01)m0.

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Polarization-Induced 2D Electron and Holes in Undoped AlN/GaN/AlN Heterostructures

Chaudhuri

2022

Springer Theses

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Two-dimensional electron gas and persistent photoconductivity inAlxGa1−xN/

Cited by 30 publications

References 30 publications

The persistent photoconductivity effect in AlGaN/GaN heterostructures grown on sapphire and SiC substrates

The persistent photoconductivity effect in AlGaN/GaN heterostructures grown on sapphire and SiC substrates

Quantum confinement effect on the effective mass in two-dimensional electron gas of AlGaN/GaN heterostructures

Polarization-Induced 2D Electron and Holes in Undoped AlN/GaN/AlN Heterostructures

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