Current filamentation in n-GaAs thin films with different contact geometries

Schwarz, G.; Lehmann, Christian; Reimann, Arnold; Schöll, Eckehard; Hirschinger, Jérôme; Prettl, Wilhelm; Novák, V.

doi:10.1088/0268-1242/15/6/319

Cited by 17 publications

(13 citation statements)

References 42 publications

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“…Nevertheless, we mention the efforts e.g. with respect to pin-diodes (entry 1 and 2 in Table 6, [215,216,370]), n-GaAs wafers with Corbino geometry (entry 4 in Table 6, [371]) and ZnS doped with Mg (entry 8 in Table 6), [206]), and p þ -n þ -p-n À (see also entry 6 in Table 6). The latter work will be discussed in some detail in the following (see also [183,372]).…”

Section: Quantitymentioning

confidence: 99%

Dissipative solitons

Purwins¹,

Bödeker²,

Amiranashvili³

2010

Advances in Physics

220

193

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Section: Quantitymentioning

confidence: 99%

Dissipative solitons

Purwins¹,

Bödeker²,

Amiranashvili³

2010

Advances in Physics

220

193

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“…The current density filament can be seen as a bright PL pattern between the two ohmic contacts (short circuitry conditions). The width of the filament increases by increasing the applied pulse voltage [3,5,9]. In the present experiments, the amplitude of the applied pulse voltage was settled to be larger than the breakdown voltage.…”

mentioning

confidence: 69%

Anomalous PL brightening caused by impact formation of a (D ⁺ , X) complex during an impact ionization avalanche in n‐GaAs

Aoki¹

2003

phys. stat. sol. (c)

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The impact formation of the (D + , X) bound-exciton in n-GaAs at 4.2 K during an impact ionization avalanche under an applied pulse voltage has been investigated. The bright PL-pattern observed by applying the pulse voltage characterizes well the formation of a current density filament. The observations of the bright PL-pattern give a quite new result concerning the electron-impact formation process of the excitons bound to the ionized donors (D + , X).At low temperatures, high-purity semiconductors behave like insulators, because a large part of the shallow impurities is charge-neutral and only a few charge carriers can be mobile. By applying an electric field of a few V/cm, the neutral shallow impurities are completely ionized due to an impact ionization avalanche, causing the negative differential resistivity (NDR) in the current−voltage characteristic. By the low-temperature impurity breakdown, a current density filament can be formed between the ohmic contacts [1, 2]. The current density filament has been typically observed as a photoluminescence (PL) quench-pattern [3].By the PL method, Aoki and Fukui [4−6] have investigated the nucleation process of a current density filament [4] and also the nonlinear dynamics of the filament during the current instability under magnetic fields in n-GaAs [1,5,6]. Very recently, the author has found, that the PL pattern image under a short pulse voltage can be seen as a bright pattern inside the filament or along the filament boundaries in a n-GaAs Corbino disc [7,8], where the anomalous brightening of the PL intensity was seen under a very weak photoexcitation density. In this paper, the anomalous PL brightening during the impact ionization avalanche of the neutral shallow donors is discussed in detail, and a new interpretation of the impact formation of the excitons bound to ionized donors is given.All of the measurements were done at 4.2 K, using a high-purity n-GaAs sample with a thickness of the epitaxial layer of 21 µm grown on a semi-insulating substrate. The electron density and the electron mobility were n = 6.23 × 10 13 cm −3 and µ = 1.23 × 10 5 cm 2 /Vs at 77 K, respectively. The area of the sample surface was approximately (6.0 × 6.0) mm 2 , on which the disk-shaped ohmic contacts were formed (see Fig. 1). The sample surface was very weakly excited by a 35 mW (or 20 mW) He−Ne laser beam, where the laser beam was spread over the whole sample surface by using a spatial filter and strongly attenuated by using neutral density filters. The photon density was J p ≈ 63 µW/cm 2 . The spatiotemporal

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“…2 Nevertheless, so far the greatest theoretical attention has been paid to the model of two-level generation-recombination kinetics 6,7 and to Monte-Carlo calculation based generalizations of this model. [8][9][10] This is primarily due to the fact that the latter approach has been proven to yield a solid theoretical basis for the explanation and modeling of the spontaneous formation of current carrying filaments, 11,12 which is characteristic in the postbreakdown regime of n-GaAs ͑Refs. 13-15͒ and SNDC materials generally.…”

Section: Introductionmentioning

confidence: 99%

Electron mobility measurement inn−GaAsat low-temperature impurity breakdown

Novák¹,

Cukr²,

Schowalter³

et al. 2000

Phys. Rev. B

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Using a combination of the standard Hall technique and the photoluminescence imaging of galvanomagentic transport, free-electron density and mobility have been measured in the regime of filamentary current flow after the electric breakdown of n-GaAs at the temperature of liquid helium. The data show good agreement with those acquired by the geometrical magnetoresistance effect and by the optical Hall angle measurement. By comparing the mobilities obtained by independent techniques, arguments have been found indicating significant neutral impurity scattering in the post-breakdown regime. In the pre-breakdown regime variable range hopping has been concluded as the dominant transport mechanism.

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Current filamentation in n-GaAs thin films with different contact geometries

Cited by 17 publications

References 42 publications

Dissipative solitons

Dissipative solitons

Anomalous PL brightening caused by impact formation of a (D ⁺ , X) complex during an impact ionization avalanche in n‐GaAs

Electron mobility measurement inn−GaAsat low-temperature impurity breakdown

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Current filamentation in n-GaAs thin films with different contact geometries

Cited by 17 publications

References 42 publications

Dissipative solitons

Dissipative solitons

Anomalous PL brightening caused by impact formation of a (D + , X) complex during an impact ionization avalanche in n‐GaAs

Electron mobility measurement inn−GaAsat low-temperature impurity breakdown

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Product

Resources

About

Anomalous PL brightening caused by impact formation of a (D ⁺ , X) complex during an impact ionization avalanche in n‐GaAs