Enhancement of the Hall mobility in undoped GaAs with low carrier concentration by light excitation

Kažukauskas, V.; Kühnel, G.; Siegel, W.

doi:10.1063/1.118646

Cited by 17 publications

(9 citation statements)

References 14 publications

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“…The Si-doped layer is characterized by a maximum at 150 K. Below 150 K the scattering at screened Coulomb potentials ͑ionized dislocations, point defects, and impurities͒ and above 150 K the scattering at phonons ͑polar, deformation, and piezoelectric potentials͒ dominates the mobility. 9 In the case of potential fluctuations, the potential barriers can be overcome by the photoexcited electrons. This result can be explained by the assumption of a dominant scattering at inhomogeneities in the low-temperature region decreasing the measured mobility ͑see also Refs, 4 and 5͒.…”

Section: A Photo-hall-effect Measurementsmentioning

confidence: 99%

Correlation between macroscopic transport parameters and microscopic electrical properties in GaN

Witte

Krtschil

Schrenk

et al. 2005

Journal of Applied Physics

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Section: A Photo-hall-effect Measurementsmentioning

confidence: 99%

Correlation between macroscopic transport parameters and microscopic electrical properties in GaN

Witte

Krtschil

Schrenk

et al. 2005

Journal of Applied Physics

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“…The compilation of Table 3 shows, that grain barriers or other structural inhomogeneities affect significantly the carrier transport in polycrystalline as well as heteroepitaxially grown semiconducting films, independently of the material. For instance, also for gallium nitride films grown by MOCVD on sapphire substrates [44] and for GaAs layers [45] internal potential barriers (i.e. grain barriers) were recently reported to influence the carrier transport.…”

Section: Amentioning

confidence: 99%

Carrier transport in polycrystalline transparent conductive oxides: A comparative study of zinc oxide and indium oxide

Ellmer

Mientus²

2008

Thin Solid Films

335

191

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Highly-doped indium-tin oxide films exhibit resistivities ρ as low as 1. . Thus the grain barrier trap densities of ZnO and ITO are significantly different, which seems to be connected with the defect chemistry of the two oxides and especially with the piezoelectricity of zinc oxide.Keywords Transparent conductive oxides, carrier transport, degenerate semiconductors, grain barriers, electron mobility 2 Therefore, in the present study the carrier transport processes in ITO and ZnO are compared in order to get a deeper understanding of the differences between these TCO materials. For this purpose conductivity and Hall mobility measurements on ZnO:Al and ITO films were undertaken for films deposited on amorphous as well as single crystalline substrates (sapphire) in order to determine the dominant scattering processes (ionized impurities, grain barriers, crystallographic defects). Our own data are compared with literature data reported for ZnO and ITO to show the general trends. Theoretical and semiempirical models are used to fit the experimental data and to derive characteristic material parameters for these three oxides. Introduction Theoretical modelsThe theoretical models on ionized impurity scattering were already reviewed in 2001 by one of the authors when estimating the mobility limit of highly-doped zinc oxide [3]. In the following a short summary is given to lay the basis for the further discussion.Ionized impurity scattering. This scattering process is caused by ionized dopant atoms and dominates for carrier concentrations above about 10 19 cm -3. An analytical expression for the mobility µ ii of degenerately doped semiconductors, taking into account the non-parabolicity of the conduction band, was given by Zawadzki [7] and refined by Pisarkiewicz et al. [6]:where the screening functionwith the parameter ξ np =1-m 0 */m*, which describes the non-parabolicity of the conduction band (m*, m 0 * -effective masses in the conduction band and at the conduction band edge, 4 respectively). The prefactor in equ. (1) The fit parameters µ max , µ min and µ min -µ 1 describe the lattice mobility at low carrier concentrations, the mobility limited by ionized impurity scattering and the clustering mobility, discussed above (see Table 2). . The ZnO mobility values were fitted using the empirical formula (3) and the fit parameters are summarized in Table 2 together with the corresponding values for silicon. In the transition region from lattice to ionized scattering for 5 . 10 16 < N < 5 . 10 18 cm -3 a large scattering of the experimental ZnO data can be observed. Therefore, the data have been fitted in analogy to the silicon data, which exhibit a much higher accuracy [14].However, the exact transition does not influence the conclusions much since we are interested predominantly in ionized impurity scattering in the region N > 10 19 cm -3 .5 Neutral impurity scattering. Neutral shallow-impurity scattering is often discussed in papers about transport in TCO films at room temperature [17,18]. The mobility due to ...

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“…8,9,11,17,18 The mobility was shown to scale with n ␣ , although the magnitude of ␣ appears to depend strongly on materials' properties and experimental conditions such as temperature.…”

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Electron irradiation-induced increase of minority carrier diffusion length, mobility, and lifetime in Mg-doped AlN∕AlGaN short period superlattice

Lopatiuk-Tirpak

Chernyak

Borisov

et al. 2007

Applied Physics Letters

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Minority carrier diffusion length in a p-type Mg-doped AlN∕Al0.08Ga0.92N short period superlattice was shown to undergo a multifold and persistent (for at least 1week) increase under continuous irradiation by low-energy beam of a scanning electron microscope. Since neither the diffusion length itself nor the rate of its increase exhibited any measurable temperature dependence, it is concluded that this phenomenon is attributable to the increase in mobility of minority electrons in the two-dimensional electron gas, which in turn is limited by defect scattering. Cathodoluminescence spectroscopy revealed ∼40% growth of carrier lifetime under irradiation with an activation energy of 240meV.

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Enhancement of the Hall mobility in undoped GaAs with low carrier concentration by light excitation

Abstract: Hall mobility lowering in undoped n -type bulk GaAs due to cellular-structure related nonuniformities

Cited by 17 publications

References 14 publications

Correlation between macroscopic transport parameters and microscopic electrical properties in GaN

Correlation between macroscopic transport parameters and microscopic electrical properties in GaN

Carrier transport in polycrystalline transparent conductive oxides: A comparative study of zinc oxide and indium oxide

Electron irradiation-induced increase of minority carrier diffusion length, mobility, and lifetime in Mg-doped AlN∕AlGaN short period superlattice

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