Different Fermi-level pinning behavior on<i>n</i>- and<i>p</i>-type GaAs(001)

Pashley, M. D.; Haberern, K. W.; Feenstra, R. M.; Kirchner, P. D.

doi:10.1103/physrevb.48.4612

Cited by 128 publications

(66 citation statements)

References 8 publications

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“…43 In contrast, bulk doping of GaAs has been found to be fairly ineffective for passivating surface-defect states, in particular for high-quality n-doped GaAs, because of the formation of surface acceptor states by a self-compensation mechanism. 51 Here we find that functional conjugated polymers, such as P3HT, can be highly effective electron-donating reagents for inorganic semiconductors as they appear to induce a δ-electron doping layer on the surface of GaAs. Since the active surface states of the nanowires investigated here are electron-deficient in chemical character, electron doping will be essential to reduce the unsaturated surface-state density.…”

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confidence: 86%

Strong Carrier Lifetime Enhancement in GaAs Nanowires Coated with Semiconducting Polymer

et al. 2012

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ABSTRACT:The ultrafast charge carrier dynamics in GaAs/ conjugated polymer type II heterojunctions are investigated using time-resolved photoluminescence spectroscopy at 10 K. By probing the photoluminescence at the band edge of GaAs, we observe strong carrier lifetime enhancement for nanowires blended with semiconducting polymers. The enhancement is found to depend crucially on the ionization potential of the polymers with respect to the Fermi energy level at the surface of the GaAs nanowires. We attribute these effects to electron doping by the polymer which reduces the unsaturated surfacestate density in GaAs. We find that when the surface of nanowires is terminated by native oxide, the electron injection across the interface is greatly reduced and such surface doping is absent. Our results suggest that surface engineering via π-conjugated polymers can substantially improve the carrier lifetime in nanowire hybrid heterojunctions with applications in photovoltaics and nanoscale photodetectors.

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confidence: 86%

Strong Carrier Lifetime Enhancement in GaAs Nanowires Coated with Semiconducting Polymer

et al. 2012

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“…In addition, the III-V semiconductor surface itself may be prone to high D it . Vacancies, antisite defects, or incomplete dimerization of the III-V surface can result in unsaturated bonds and form electrically active traps [3][4][5] that may be present even before high-k dielectric growth or are generated during the deposition. Methods capable of quantifying D it , the trap level energy position and the degree of Fermi level ͑un͒pinning are critical in the development of high-quality high-k/III-V interfaces.…”

Section: Introductionmentioning

confidence: 99%

Comparison of methods to quantify interface trap densities at dielectric/III-V semiconductor interfaces

Engel‐Herbert

Hwang

Stemmer

2010

Journal of Applied Physics

372

273

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Methods to extract trap densities at high-permittivity ͑k͒ dielectric/III-V semiconductor interfaces and their distribution in the semiconductor band gap are compared. The conductance method, the Berglund intergral, the Castagné-Vapaille ͑high-low frequency͒, and Terman methods are applied to admittance measurements from metal oxide semiconductor capacitors ͑MOSCAPs͒ with high-k / In 0.53 Ga 0.47 As interfaces with different interface trap densities. The results are discussed in the context of the specifics of the In 0.53 Ga 0.47 As band structure. The influence of different conduction band approximations for determining the ideal capacitance-voltage ͑CV͒ characteristics and those of the MOSCAP parameters on the extracted interface trap density are investigated. The origins of discrepancies in the interface trap densities determined from the different methods are discussed. Commonly observed features in the CV characteristics of high-k / In 0.53 Ga 0.47 As interfaces are interpreted and guidelines are developed to obtain reliable estimates for interface trap densities and the degree of Fermi level ͑un͒pinning for high-k / In 0.53 Ga 0.47 As interfaces.

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“…Donors or acceptors are uniformly distributed in the narrow GaAs quantum well (QW). For p doping we assume a Fermi level pining at 400 meV above the valence-band edge [34], while for n doping we assume midgap pinning. The PL phenomenological linewidth γ = 0.5 meV and all calculations have been performed at temperature T = 1.8 K.…”

Section: A Structure Detailsmentioning

confidence: 99%

Magnetophotoluminescence in GaAs/AlAs core-multishell nanowires: A theoretical investigation

et al. 2015

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The magnetophotoluminescence in modulation doped core-multishell nanowires is predicted as a function of photoexcitation intensity in nonperturbative transverse magnetic fields. We use a self-consistent field approach within the effective mass approximation to determine the photoexcited electron and hole populations, including the complex composition and anisotropic geometry of the nanomaterial. The evolution of the photoluminescence is analyzed as a function of (i) photoexcitation power, (ii) magnetic field intensity, (iii) type of doping, and (iv) anisotropy with respect to field orientation.

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Different Fermi-level pinning behavior onn- andp-type GaAs(001)

Cited by 128 publications

References 8 publications

Strong Carrier Lifetime Enhancement in GaAs Nanowires Coated with Semiconducting Polymer

Strong Carrier Lifetime Enhancement in GaAs Nanowires Coated with Semiconducting Polymer

Comparison of methods to quantify interface trap densities at dielectric/III-V semiconductor interfaces

Magnetophotoluminescence in GaAs/AlAs core-multishell nanowires: A theoretical investigation

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