Electrical transport properties of single undoped and n-type doped InN nanowires

Richter, T.; Lüth, H.; Schäpers, Thomas; Meijers, R.; Jeganathan, K.; Hernandez, S. Estevez; Calarco, Raffaella; Marso, Michel

doi:10.1088/0957-4484/20/40/405206

Cited by 48 publications

(54 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8,11,25,[31][32][33][34] Moreover, it has been generally observed that there exists a very high electron concentration (∼ 1 × 10 13−14 cm −2 ) at both the polar and nonpolar grown surfaces of InN films, 19,35 and the Fermi-level (E F ) is pinned deep into the conduction band at the surfaces; 19,20,29,30 similar electron accumulation profile has also been measured at the lateral nonpolar grown surfaces of [0001]-oriented wurtzite InN nanowires. 8,11,21,22,25,36 In this regard, significant efforts have been devoted to understanding the fundamental surface charge properties of InN. 20,23,27,29,30,[37][38][39] The electron accumulation at polar InN surface has been explained by the presence of large density of the occupied In-In bond states above the conduction band minimum (CBM), 23 as well as the unusual positioning of the branch point energy (E B ) well above the CBM at the Γ-point, which allows donor-type surface states to exist in the conduction band; 20 for polar InN surface, theoretical studies agree well with experiments.…”

mentioning

confidence: 69%

“…8,[19][20][21][22][23][24][25][26][27][28][29][30] For example, in general, the currently reported nominally undoped InN is n-type degenerate, with the residual electron densities in the range of ∼ 1 × 10 18 cm −3 , or higher. 8,11,25,[31][32][33][34] Moreover, it has been generally observed that there exists a very high electron concentration (∼ 1 × 10 13−14 cm −2 ) at both the polar and nonpolar grown surfaces of InN films, 19,35 and the Fermi-level (E F ) is pinned deep into the conduction band at the surfaces; 19,20,29,30 similar electron accumulation profile has also been measured at the lateral nonpolar grown surfaces of [0001]-oriented wurtzite InN nanowires. 8,11,21,22,25,36 In this regard, significant efforts have been devoted to understanding the fundamental surface charge properties of InN.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

Zhao

Kibria

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

In the present work, photoluminescence characteristics of intrinsic and Si-doped InN nanowires were studied in details. For intrinsic InN nanowires, the emission is due to band-to-band carrier recombination with the peak energy at ∼ 0.64 eV (at 300 K), and may involve free-exciton emission at low temperatures. The PL spectra exhibit a strong dependence on optical excitation power and temperature, which can be well characterized by the presence of very low residual electron density, and the absence or negligible level of surface electron accumulation. In comparison, the emission of Si-doped InN nanowires is characterized by the presence of two distinct peaks located at ∼ 0.65 eV and ∼ 0.73 − 0.75 eV (at 300 K). Detailed studies further suggest that these low-energy and highenergy peaks can be ascribed to band-to-band carrier recombination in the relatively low-doped nanowire bulk region and Mahan exciton emission in the high-doped nanowire near-surface region, respectively; this is a natural consequence of dopants surface segregation. The resulting surface electron accumulation and Fermi-level pinning, due to the enhanced surface doping, is confirmed by angle-resolved X-ray photoelectron spectroscopy measurements on Si-doped InN nanowires, which is in direct contrast to the absence, or negligible level of surface electron accumulation in intrinsic InN nanowires. This work has elucidated the role of charge carrier concentration and distribution on the optical properties of InN nanowires.

show abstract

mentioning

confidence: 69%

mentioning

confidence: 99%

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

Zhao

Kibria

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…An additional error in the values of n 3d enters because of interface states in the gate layer stacks, which are simultaneously recharged with the wire under the gate. 35 Therefore, the absolute values of n 3d presented in Fig. 7 can be considered as an upper limit and are systematically lower to a certain extent.…”

Section: à3mentioning

confidence: 96%

“…Up to now, successful n-or p-type doping has already been reported for various III-V semiconductor nanowires, such as InAs, 7,[30][31][32] GaAs, 33,34 or InN nanowires. 35 The doping of InAs nanowires by SA-MOVPE has not been reported, especially at the high growth temperature needed when using an N 2 ambient. Here, we studied the impact of Si doping on the nanowire morphology, structure, and conductivity.…”

Section: Introductionmentioning

confidence: 99%

Effect of Si-doping on InAs nanowire transport and morphology

Wirths¹,

Weis²,

Winden³

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

The effect of Si-doping on the morphology, structure, and transport properties of nanowires was investigated. The nanowires were deposited by selective-area metal organic vapor phase epitaxy in an N 2 ambient. It is observed that doping systematically affects the nanowire morphology but not the structure of the nanowires. However, the transport properties of the wires are greatly affected. Room-temperature four-terminal measurements show that with an increasing dopant supply the conductivity monotonously increases. For the highest doping level the conductivity is higher by a factor of 25 compared to only intrinsically doped reference nanowires. By means of back-gate field-effect transistor measurements it was confirmed that the doping results in an increased carrier concentration. Temperature dependent resistance measurements reveal, for lower doping concentrations, a thermally activated semiconductor-type increase of the conductivity. In contrast, the nanowires with the highest doping concentration show a metal-type decrease of the resistivity with decreasing temperature.

show abstract

“…From measurements on nanowires contacted with normal contacts with various distances a specific resistance of ρ = 4.2 × 10 −4 Ωcm was estimated. 19 Using these values we calculated a diffusion constant of D = 110 cm 2 /s.…”

mentioning

confidence: 99%

Josephson supercurrent in Nb/InN-nanowire/Nb junctions

Frielinghaus

Batov

Weides

et al. 2010

Applied Physics Letters

View full text Add to dashboard Cite

We experimentally studied the Josephson supercurrent in Nb/InN-nanowire/Nb junctions. Large critical currents up to 5.7 µA have been achieved, which proves the good coupling of the nanowire to the superconductor. The effect of a magnetic field perpendicular to the plane of the Josephson junction on the critical current has been studied. The observed monotonous decrease of the critical current with magnetic field is explained by the magnetic pair-breaking effect in planar Josephson junctions of ultra-narrow width [J. C. Cuevas and F. S. Bergeret, Phys. Rev. Lett. 99, 217002 (2007)] Superconductor/normal-conductor/superconductor (SNS) junctions with a semiconductor employed as the N-weak link material offer the great advantage that here the Josephson supercurrent can be controlled by means of the field effect. 1,2 Gate-controlled superconductor/semiconductor hybrid devices such as superconducting field effect transistors 3 or split-gate structures 4 have been fabricated which find no counterpart in conventional SNS structures. In addition, the high carrier mobility attainable in semiconductors in combination with the phase-coherent Andreev reflection leads to novel unique phenomena in the magnetotransport. 5-7 Usually for these devices the semiconductor is patterned by conventional lithography. As an elegant alternative one can also directly create semiconductor nanostructures, i.e. nanowires, by epitaxial growth. 8 By using InAs nanowires connected to superconducting electrodes tunable Josephson supercurrents, supercurrent reversal, and Kondo-enhanced Andreev tunneling have been realized. [9][10][11] Among the various materials used for semiconductor nanowires InN is of particular interest for semiconductor/superconductor hybrid structures, since the surface accumulation layer in InN can provide a sufficiently low resistive contact to superconducting electrodes. 12-14 Due to almost ideal crystalline properties of InN nanowires electronic transport along the wires, contacted by normal metal electrodes, shows quantization phenomena, i.e. flux periodic magnetoconductance oscillations. 15 Furthermore, the carrier concentration in the surface electron gas is of the order of 10 13 cm −2 and thus about a factor of ten larger than in InAs. Consequently when combined with superconducting electrodes one can expect low resistive SNS junctions.Here, we report on transport studies of Nb/InNnanowire/Nb junctions. We succeeded in observing a pronounced Josephson supercurrent and a relatively large I c R N product of up to 0.44 mV. The latter factor, the critical current times the normal resistance, is an important figure of merit for Josephson junctions. We devoted special attention to the dependence of the critical current I c on an external magnetic field B, where a monotonous decrease of I c with B was found. This experimental finding is interpreted in the framework of a recent theoretical model for the proximity effect in narrow-width junctions with dimensions comparable or smaller than the magnetic length ξ B = Φ 0 /B,...

show abstract

Electrical transport properties of single undoped and n-type doped InN nanowires

Cited by 48 publications

References 25 publications

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

Effect of Si-doping on InAs nanowire transport and morphology

Josephson supercurrent in Nb/InN-nanowire/Nb junctions

Contact Info

Product

Resources

About