Electron mobilities, Hall factors, and scattering processes of<i>n</i>-type GaN epilayers studied by infrared reflection and Hall measurements

Fu, Ying; Willander, Magnus; Zf, Li; Lü, Wei

doi:10.1103/physrevb.67.113313

Cited by 9 publications

(7 citation statements)

References 7 publications

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“…The reflective spectra shown in Figure 2 were measured at the center of the GaN substrates. In the frequency region above 10 THz , they were in agreement with (2) for each carrier density, with values of Γ = 17 cm −1 , γ = 12 cm −1 , ω L = 744 cm −1 , ω T = 560 cm −1 , m * = 0.2 m, and ε inf = 5.35 used [6,9]. γ was obtained from the typical value of the mobility µ = 150 cm/Vs from the literature.…”

Section: Resultssupporting

confidence: 71%

Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Ohno

Hamano²,

Miyamoto

et al. 2009

JEOS:RP

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We developed a method for mapping the carrier density on a semiconductor substrate surface based on terahertz (THz)-reflective measurement. Reflectivity in the THz-frequency region away from the optical phonon frequency is sensitive to the carrier density in semiconductors. However, reflectivity in the optical phonon frequency regions is around 1.0, independent of the carrier density. We developed a THz-reflective spectral imaging system using a frequency-agile, ultra-widely tunable THz source (1-40 THz). Different reflective images were obtained from GaN samples of carrier density 2.5 × 10 16 cm-3 , 1.0 × 10 18 cm-3 and 1.5 × 10 18 cm-3 using 22.7 and 26.5 THz. The image contrast reflected the GaN crystals' carrier density.

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Section: Resultssupporting

confidence: 71%

Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Ohno

Hamano²,

Miyamoto

et al. 2009

JEOS:RP

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“…The results are shown in Fig. 1, in which the measured Hall mobilities [9]- [12] were converted into drift mobilities using appropriate Hall factors [11]. The simulated mobilities are in good agreement with the experimental values, with the lower measured values corresponding to samples with high dislocation density.…”

Section: Resultsmentioning

confidence: 57%

Temperature- and Doping-Dependent Anisotropic Stationary Electron Velocity in Wurtzite GaN

Sridharan

Christensen

Venkatachalam

et al. 2011

IEEE Electron Device Lett.

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The influences of temperature, dopant density, freecarrier density, and field orientation on the electron drift mobility and velocity-field relationship in wurtzite c-axis GaN are quantified by means of theoretical investigation. Electron velocity perpendicular to the growth plane is uniformly lower than that parallel to the growth plane for field strengths below 500 kV/cm, although anisotropy within the basal plane itself is found to be insignificant. The calculated low-field electron mobility is demonstrated to be consistent with recent Hall measurements over a range of dopant densities. Low-field mobility is enhanced under the influence of free-carrier densities above the background doping due to both increased screening of ionized impurities and a reduction in A1-LO phonon lifetime through the plasmon-phonon interaction.Index Terms-Electron velocity, ionized impurity, phonon population, wurtzite gallium nitride (GaN).

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“…The mobility range was higher than the 150 cm 2 V À1 s À1 to 250 cm 2 V À1 s À1 that Fu et al and others reported for similarly doped, bulk GaN. 31,32 GaN films often have dislocation densities of 8 9 10 9 cm À2 . 32 Transmission electron microscopy (TEM) examination of individual nanowires shows that our MBE-grown nanowires are free of dislocations.…”

Section: Modelmentioning

confidence: 77%

GaN Nanowire Carrier Concentration Calculated from Light and Dark Resistance Measurements

Mansfield

Bertness

Blanchard

et al. 2009

Journal of Elec Materi

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We obtained the carrier concentration and mobility of silicon-doped gallium nitride nanowires at room temperature with light and dark resistance data. Current-voltage measurements were performed on single-nanowire devices in the dark and under 360 nm illumination. Field-emission scanning electron microscopy was used to measure the device dimensions. The nanowires were modeled with cylindrical geometry, and solutions were computed with a nonlinear fit algorithm. Simulations were also performed to verify the model. The carrier concentration was bounded by 6 9 10 17 cm À3 and 1.3 9 10 18 cm À3 , and the mobility was between 300 cm 2 V À1 s À1 and 600 cm 2 V À1 s À1 .

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Electron mobilities, Hall factors, and scattering processes ofn-type GaN epilayers studied by infrared reflection and Hall measurements

Cited by 9 publications

References 7 publications

Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Temperature- and Doping-Dependent Anisotropic Stationary Electron Velocity in Wurtzite GaN

GaN Nanowire Carrier Concentration Calculated from Light and Dark Resistance Measurements

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