Minimum Resistivity Research Articles

Asymmetric Bipolar Pulsed dc Sputtered Nanocrystalline VN Coatings for Electrode Materials in Lithium Battery.

Nanocrystalline vanadium nitride (VN) coatings for electrode materials for lithium battery with various deposition parameters have been prepared using dc and asymmetric bipolar pulsed dc magnetron sputtering. The deposition parameters such as pulse frequency and the duty cycle were varied from 0 to 50 kHz and 100 to 75%, respectively. Microstructural, crystallographic and electrical characterizations were performed by FE-SEM, AFM, XRD and 4-point probe method. With an increase in pulse frequency, coating microstructure evolved from a porous columnar structure to a highly dense one. Single- phase cubic (FCC) VN coatings with different preferential orientations were obtained as a function of pulse frequency. Minimum resistivity of 108 μΩ-cm was obtained for the coatings deposited at pulse frequency of 25 kHz.

Asymmetric Bipolar Pulsed dc Sputtered Niobium Nitride Films for Electrode Materials in Supercapacitors.

Niobium nitride (NbN) films were deposited using asymmetric-bipolar pulsed dc sputtering at different pulse parameters. Microstructural, electrical and mechanical characterizations were performed by FE-SEM, AFM, LCR meter and nanoindentator. The results show that pulse frequency has significant effects on coating's microstructure, structural and electrical properties of NbN films. With an increase in pulse frequency, coating microstructure evolved from a porous columnar structure to a highly dense one. Average crystal grain sizes of NbN films were decreased from 52.7 nm to 27.5 nm with an increase in pulse frequency. The minimum resistivity of 351 μΩ-cm, the smoothest surface morphology with Ra roughness of 0.4 nm and the maximum hardness of 17.4 GPa were obtained for the films deposited at pulse frequency of 50 kHz, respectively.

Revival of Metal-Insulator and Ferromagnetic-Paramagnetic Transitions by Ni Substitution at Mn Site in Charge-Ordered Monovalent Doped Nd0.75Na0.25MnO3 Manganites

Nd0.75Na0.25Mn1−xNi x O3 (x = 0 − 0.07) were synthesized using a conventional solid-state synthesis method to investigate the effect of Ni substitution on their magnetic and electrical transport properties. XRD analysis using the Rietvield refinement method showed an increase in unit cell volume with increasing Ni content, indicating the possibility of substituting Ni for the Mn site. For x = 0, magnetization measurements showed paramagnetic (PM) to antiferromagnetic (AFM) transition at the transition temperature, TN ∼ 185 K, which may be related to the presence of charge-ordering (CO) state. For Ni-substituted samples, ferromagnetic (FM) to PM transition was induced with Curie temperature (TC), increasing from 91 K (x = 0.01) to 115 K (x = 0.03), followed by decreases in TC to 60 K (x = 0.07). Electrical resistivity measurements showed that samples for x ≤ 0.01 exhibited insulator behavior while both x = 0.03 and 0.05 samples exhibited metal-insulator transition suggesting that the CO state is weakened. For x = 0.07, the sample shows re-entrant of insulating characteristic. Inducement of FM metallic (FMM) state, as well as increased of TC for x = 0.03 is suggested to be related to FM SE between Ni2+ and Mn4+, which suppressed the CO state, hence inducing double-exchange (DE)-like mechanism. In addition, an increase in resistivity was observed as temperature decreased below the resistivity minimum (Rmin) at Tmin ∼ 40 K for x = 0.05 is possibly due to the Kondo-like effect mechanism. On one hand, the M(H) curve showed the presence of a hysteresis loop for x = 0 and 0.01 at T= 60 and 80 K, indicating the presence of an unstable phase, which may be related with the CO-AFM phase. For x = 0.03, no hysteresis loop was observed, indicating the suppression of the CO-AFM. Intriguingly, for x = 0.05 and 0.07, small hysteresis loop was observed, indicating the possible presence of a minor AFM component. Further, the observed MR behavior in present studies can be understood as a result of a decreased scattering mechanism in the presence of magnetic field.

Variable-range hopping conductivity in Lu-doped Bi2Te3

The Seebeck coefficient enhancement due to an increase of density-of-states effective mass of electron has been found in n-type Bi1.9Lu0.1Te3. This enhancement is assumed to be related to forming the narrow and non-parabolic impurity (Lu) band with local maximum of electronic density of states lying near the Fermi level. Minimum in the specific electrical resistivity, ρ, originated from change of conductivity mechanism was observed at temperature Tm ≈ 11 K. Above Tm, the ρ change is due to decrease of electron mobility via acoustic phonon scattering. Below Tm, the variable-range hopping conductivity takes place. The electron hops between the localized states of the impurity energy band occur via tunneling process. Using the temperature and magnetic field dependences of ρ, the localization radius of electron was estimated as ≈6 nm. Two parts in the magnetic field dependence of the electrical resistivity were found at temperature of 2 K. At weak magnetic fields, the ρ change is in agreement with the variable-range hopping conductivity mechanism. At high magnetic fields, the positive and almost linear transverse and longitudinal magnetoresistances were observed at low temperatures. Both variable-range hopping conductivity and positive linear magnetoresistance are characteristics of disordered and inhomogeneous semiconductors.

Effects of substrate temperature on the properties of the indium tin oxide thin films deposited by sputtering method

High-quality transparent conductive indium tin oxide (ITO) thin films were deposited on glass substrates using radio frequency sputtering method. The structure and electrical and optical properties of the ITO thin films were mainly investigated. The ITO thin films showed strong diffraction peak having a preferred orientation along the [111] direction as the deposition temperature at 120 to 160 °C. In the transmission spectra, the optical transmittance increased in the visible range as the deposition temperature increased from RT to 160 °C. A minimum resistivity of 3.06×10-3 Ω-cm was obtained for the ITO thin film deposition at 160 °C.

Plasma-enhanced atomic layer deposition of nickel thin film using bis(1,4-diisopropyl-1,4-diazabutadiene)nickel

The authors report the plasma enhanced atomic layer deposition (PEALD) of a nickel thin film using bis(1,4-diisopropyl-1,4-diazabutadiene)nickel [Ni(dpdab)2] and NH3 plasma. Ni(dpdab)2 is an oxygen-free liquid Ni precursor with a vapor pressure of 0.23 Torr at 80 °C. Ni films were deposited by alternating exposures to Ni(dpdab)2 and NH3 plasma at 125–250 °C. Ni(dpdab)2 showed the atomic layer deposition (ALD) process window between 125 and 150 °C with the ALD growth of ∼2 Å/cycle. The growth rate increased significantly above 200 °C, probably due to the thermal decomposition of the Ni precursor. The resistivity of the ALD thin film decreased with increasing radio-frequency (RF) power, and lower resistivities with high RF powers are due to the lower carbon concentration and larger grain size. The minimum resistivity of the PEALD film at 150 °C in the ALD process window was 146 μΩ cm, which is significantly higher than bulk Ni resistivity (7.0 μΩ cm) mainly due to the nitrogen content (∼13%) in the as-deposited film. For a lower nitrogen concentration, the PEALD film was annealed at 400 °C under 1 Torr of H2 for 30 min, resulting in the reduction of resistivity from 146 to 13.3 μΩ cm and removal of nitrogen impurities.

Analysis of leaks from geomembrane in a sanitary landfill through models of electrical resistivity tomography in South Brazil

Landfills are the main destination of solid waste generated in Brazil. Based on technical criteria, the construction of a landfill aims to minimize environmental impacts since it can present problems of high complexity. This paper discusses the use of electric resistivity tomography applied in a waste cell of a landfill, and its objective is to evaluate the effectiveness of such tool in the detection of possible leachate’s leakage points in the landfill’s geomembrane. The leachate is a liquid effluent characterized by a high content of dissolved salts produced by the decomposition of organic matter. Therefore, a signature of low electrical resistivity defines the presence of this compound in soil and groundwater. The analysis of 12 sections of electrical resistivity tomography in Schlumberger arrangement allowed the estimation of 47 Ω m as the minimum resistivity value for the natural conditions, in addition to the possibility to provide the identification of the area under the waste cell with lower resistivity values. The integration of a software that compiles 2D data into 3D viewing models enabled isosurface adjustments of 7 and 14 Ω m in resistivity maps to − 4 and − 10 m depth levels at the base of the landfill and the aquifer, respectively. These areas define points of infiltration in soil, by leakage at geomembrane in the bottom of the landfill. The results show the applicability of the method in the diagnosis of leachate contamination in a high-complexity environment. In addition, it is possible to establish an effective system for the remediation in a place where the installation of monitoring wells can increase the environmental impact.

Structural, optical and electrical properties of DC sputtered indium saving indium-tin oxide (ITO) thin films

Amorphous indium tin oxide (ITO) thin films with reduced to 50 mass% indium oxide content were prepared by direct current (DC) sputtering of ITO target in mixed argon-oxygen atmosphere onto glass substrates preheated at 523 K. The films were subsequently heat-treated in air at different temperatures in the range of 523–923 K for 60 min. The use of oxygen during deposition resulted in highly transparent (>80%) in visible and infrared ranges of spectra films. It has been found from the electrical measurements that as-deposited films under optimum sputtering conditions at working gas flow rate of Q(Ar)/Q(O2) = 50 sccm/0.5 sccm showed minimum volume resistivity of about 694 μΩcm. As-deposited thin films obtained under the optimum condition showed amorphous structure. Improving of crystallisation has been observed with increasing heat treatment temperature. It has been found that DC sputtered films with decreasing amount of indium oxide have smooth surface in contrast to typical ITO (90 mass% indium oxide).

Electrical resistivity of fluid methane multiply shock compressed to 147 GPa

ABSTRACTShock wave experiments were carried out to measure the electrical resistivity of fluid methane. The pressure range of 89–147 GPa and the temperature range from 1800 to 2600 K were achieved with a two-stage light-gas gun. We obtained a minimum electrical resistivity value of 4.5 × 10−2 Ω cm at pressure and temperature of 147 GPa and 2600 K, which is two orders of magnitude higher than that of hydrogen under similar conditions. The data are interpreted in terms of a continuous transition from insulator to semiconductor state. One possibility reason is chemical decomposition of methane in the shock compression process. Along density and temperature increase with Hugoniot pressure, dissociation of fluid methane increases continuously to form a H2-rich fluid.

Detailed survey on minimum activation energy for penetration of Ni nanoparticles into Bi-2223 crystal structure and temperature-dependent Ni diffusivity

The primary contributions of this study are not only to explore the role of diffusion annealing temperature interval 650 to 850 °C on the formation of effective electron–phonon coupling or cooper-pair probabilities (percentage of clusters in the superconducting path), densities of active and dynamic electronic states at Fermi energy level, stabilization of superconductivity in the homogeneous regions, overlapping of Cu-3d and O-2p wave functions and bond strengths in the crystal matrix of Ni surface-layered Bi-2223 polycrystalline ceramics, but also to determine the temperature-dependent diffusion fast-rate and required minimum activation energy for the diffusion of Ni foreign impurities into the bulk Bi-2223 superconducting crystal structure for the first time. The dc electrical measurement results obtained show that the optimum diffusion annealing temperature is found to be 700 °C for the penetration of optimum Ni concentration into the Bi-2223 crystal lattice so that the ceramic compound exposed to 700 °C annealing temperature exhibits the highest electrical and superconducting properties. In this respect, the material with the minimum electrical resistivity parameters of Δρ, ρ 115K , ρ res and ρ norm obtains the maximum superconducting characteristics of $$T_{c}^{{onset}}$$ , $$T_{c}^{{offset}}$$ and RRR. Accordingly, the annealing temperature of 700 °C promotes the Bi-2223 ceramics for usage in the engineering, electro-optic, industrial and large scale applications. At the same time, the diffusion coefficients [D = Doexp(E/kBT)] determined at annealing temperature ranging from 650 to 850 °C are observed to be much more significant at rather higher temperatures as compared to lower temperatures. The temperature-dependent Ni diffusion coefficient is determined to be D = 3.9707 × 10− 7exp[− 1.132 eV/kBT] for the Bi-2223 particulate solid material. Namely, the diffusion coefficient is calculated to be about 3.9707 × 10− 7cm2 s− 1 when the required minimum activation energy for the introduction of heavy metal Ni ions to the bulk Bi-2223 crystal structure is computed to be about 1.132 eV, being one of the most striking points deduced form this work.

Surface morphology evolution and optoelectronic properties of heteroepitaxial Si-doped β-Ga2O3 thin films grown by metal-organic chemical vapor deposition

Heteroepitaxial growth of conductive Si-doped β-Ga2O3 films on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) was successfully performed. The effect of Si content on the structural, morphological, electrical and optical properties of Si-doped β-Ga2O3 films was investigated in detail. Distinctive surface morphology evolution of films depending on Si content was observed and presented. The Si-doped β-Ga2O3 films exhibited high transmittance in the ultraviolet-visible regions. The temperature-dependent PL was carried out especially to discuss the photoluminescence properties of Si-doped β-Ga2O3 films. More importantly, the results suggested that the conductivity of heteroepitaxial Si-doped β-Ga2O3 films by MOCVD could be realized and controlled by adjusting the Si content. The minimum resistivity of 1.79×10−1Ω·cm was obtained for the films grown under the SiH4 flow rate of 0.08 sccm.

Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 °C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600–900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd–O bond (540 cm−1) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 × 1019 cm− 3 and 1.06 × 10−3 Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material.

Effect of charge ordering and phase separation on the electrical and magnetoresistive properties of polycrystalline La0.4Eu0.1Ca0.5MnO3

We have investigated the effect of charge ordering and phase separation on the electrical and magnetotransport properties of La0.4Eu0.1Ca0.5MnO3 polycrystalline sample. Temperature dependence of resistivity shows a metal–insulator transition at transition temperature Tρ. A hysteretic behavior is observed for zero field resistivity curves with Tρ = 128 K on cooling process and Tρ = 136 K on warming process. Zero field resistivity curves follow Zener polynomial law in the metallic phase with unusual n exponent value ∼9. Presence of resistivity minimum at low temperatures has been ascribed to the coulombic electron–electron scattering process. Resistivity modification due to the magnetic field cycling testifies the presence of the training effect. Magnetization and resistivity appear to be highly correlated. Magnetoresistive study reveals colossal values of negative magnetoresistance reaching about 75% at 132 K under only 2T applied field. Colossal values of magnetoresistance suggest the possibility of using this sample for magnetic field sensing and spintronic applications.

Structural, morphological, optical and electrical properties of e-beam deposited nanocrystalline CdTe:Cu alloy thin films from mechanical alloyed samples

Cadmium telluride (CdTe) and copper incorporated CdTe (CdTe:Cu) alloys were prepared by mechanical alloying using a planetary ball mill. X-ray diffraction results showed that the prepared CdTe:Cu alloys belong to CdTe cubic system. Surface morphology of CdTe and CdTe:Cu alloys, investigated by scanning electron microscope shows the formation of agglomerated structures of various shapes. The prepared respective sample was used as the source material to deposit CdTe and CdTe:Cu alloy thin films by e-beam evaporation method. X-ray diffraction studies showed that the films grow along (111) plane. The crystallite size of the films varies in the ∼28 to 37 nm range whereas the optical band gap is increased from 1.45 to 1.54 eV with increasing copper concentration in the CdTe:Cu alloy films. The wavelength at which maximum optical transmittance occurred in CdTe is shifted from 900 nm to 837 nm due to various level of Cu concentration in CdTe:Cu alloy films. Intensity of the photoluminescence and Raman spectra of CdTe films is decreased due to increase in the Cu concentration in CdTe:Cu alloy film. Hall measurement studies revealed that 2wt.% and 4wt.% Cu concentration in CdTe:Cu alloy film gives a minimum resistivity of ∼1.8 × 104 Ω cm.

Ni-V(or Cr) Co-addition Cu alloy films with high stability and low resistivity

In order to inhibit Cu, interconnecting in ultra-large-scale integration, from diffusing with surrounding dielectric materials and enhance its chemical inertness and maintain its excellent electrical performance as well. In this paper, the stable solid solution cluster-plus-glue-atom model was used to design the composition of Cu seed layers. In this model, insoluble element V (or Cr) was dissolved in Cu via Ni which is soluble both with Cu and V(or Cr), causing a certain degree of lattice distortion to improve the stability of Cu film. Cu-Ni-V(or Cr) alloy films were deposited directly on single crystal Si(100) substrates, without a designated barrier layer, subsequently annealed in vacuum. For the (V0.8/12.8Ni12/12.8)0.5Cu99.5 (at.%) film with the addition of large atomic radius element V, it showed the minimum electrical resistivity of 3.2 μΩ·cm after 500 °C/1 h annealing; after 500 °C/40 h annealing, no diffusion between Cu and Si was observed and the resistivity remained stable. Likewise, the (Cr1.4/13.4Ni12/13.4)0.4Cu99.6 film also remained a minimum resistivity of 3.0 μΩ·cm after annealing at 500 °C for 40 h. The greater the relative lattice distortion is in a single system, the higher the stability and the lower resistivity achieved. Obviously, the stability of Cu alloy film which satisfy the requirements of the microelectronics industry can be improved dramatically by the additive of Ni and V (or Cr) conform to the proportion of clusters.

Research into resistance to the motion of railroad undercarriages related to directing the wheelsets by a rail track

Energy saving direction on railway transport is substantiated based on reducing the motion resistance related to directing the undercarriages by a rail track. This motion resistance is defined as the kinematic resistance to motion. We clarified the nature of motion resistance associated with directing the rolling stock by a rail track. This opens up certain prospects in terms of reducing the kinematic motion resistance through design parameters of the trucks and the track. The kinematic resistance to motion could become an additional criterion for the optimal choice of characteristics of mechanical part of the undercarriages. The same applies to the permissible deviations in parameters of the rolling stock and the track.We model steady motion of a semi-wagon’s truck in a circular curve at constant velocity under the action of contact track forces, tractive force from the locomotive, and the unsuppressed centrifugal or centripetal forces of inertia. The kinematic motion resistance is determined as the longitudinal force applied to the truck’s pivot in order to balance all external forces.The dependences were obtained of specific kinematic resistance to motion on the motion velocity, base of the truck, radius of the curve, clearances of the wheelset in a rail track, and elevation of the outer rail. In particular, we derived a value of the motion velocity at which the minimum of resistance is observed. As we established, this speed does not match the equilibrium velocity and is 15−20 % lower.The study showed the possibility to predict resistance related to directing the undercarriages by a rail track. This opens up the prospect for choosing rational parameters of undercarriage gear of the rolling stock from the point of view of motion resistance

Improved electrical and thermo-mechanical properties of a MWCNT/In\u2013Sn\u2013Bi composite solder reflowing on a flexible PET substrate

Multi-walled carbon nanotube (MWCNT)/indium–tin–bismuth (In–Sn–Bi) composite nanostructures in which In–Sn–Bi nanoparticles have been penetrated by the MWCNT arrays were synthesized using a chemical reduction method. The incorporation of 0.6 wt% MWCNTs with high electrical conductivity into the In-based solder resulted in low minimum electrical resistivity (19.9 ± 1.0 µΩ·cm). Despite being reflowed at the relatively low temperature of 110 °C, the composite solder nanostructures were able to form mechanically stable solder bumps on a flexible polyethylene terephthalate (PET) substrate due to the MWCNT arrays with a high thermal conductivity of 3000 W/(m·K) and In–Sn–Bi nanoparticles with a low melting temperature of 98.2 °C. Notably, the composite solder bumps exhibited high flexibility (17.7% resistance increase over 1000 cycles of operation in a bending test) and strong adhesion strength (0.9 N average shear strength in a scratch test) on the plastic substrate because of the presence of mechanically flexible and strong MWCNTs dispersed within the solder matrix materials. These overall properties are due to the improved diffusivity of the composite solder nanostructures by the cover of the In–Sn–Bi nanoparticles along the MWCNT arrays and the network structure formation of the composite solder bumps.

High near-infrared transmittance, high intense orange luminescence in vanadium doped indium oxide (V: In2O3) thin films deposited by electron beam evaporation

The V (5wt.%) doped In2O3 (V: In2O3) thin films with the thickness of 50–150nm were deposited on to glass substrate by electron beam evaporation technique and the deposited films were annealed at 200°C in air for 2h. The annealed films were characterized by structural, electrical, optical and photoluminescence properties. X-ray diffraction (XRD) pattern shows that the film is an amorphous nature. The negative sign of the Hall coefficient indicates the n-type conductivity. Experimental results show that the resistivity and transmittance of the films are strongly influenced by film thickness and post deposition annealing. A minimum resistivity of 6.22×10−3Ωcm, a carrier concentration of 5.23×1019cm−3, a Hall mobility of 19.21cm2V−1s−1 and a figure of merit of 1.04×10−4Ω−1 are observed for the film with thickness of 150nm. After annealing the films, the average transmittance is enhanced up to 84% in the near infrared region. The blue-shift of optical band gap is found to increase from 1.62 to 2.25eV with increasing the thickness, whereas the refractive index decreases from 2.92 to 2.64. Structural disorder was observed from the Urbach’s tail. A prominent and high intense orange emission is achieved at room temperature, which may be attributed to oxygen deficiencies or intrinsic defects.

Influence of oxygen atmosphere annealing on the thermal stability of Mn1.2Co1.5Ni0.3O4±δ ceramic films fabricated by RF magnetron sputtering

This paper presents the optimal atmosphere annealing conditions for Mn1.2Co1.5Ni0.3O4±δ ceramic thin films fabricated by the RF magnetron sputtering method. The microstructure and oxygen distribution, together with electrical properties, are combined and applied for determining thermal stability. All of the Mn1.2Co1.5Ni0.3O4±δ films, which are annealed at various oxygen atmosphere from 1 × 10−3 to 1 × 105Pa, exhibit a negative temperature coefficient characteristic and show a poly-crystalline spinel structure. The film which annealed at 10Pa with the most uniform and most dense surface morphology has the minimum resistivity compared to the others. It is characterized by the highest Mn3+ and Mn4+ pair content, which gives the highest carrier concentration of ceramic films. Combined with the aging test at 125°C for 500h, the films annealed at 10Pa have the minimum resistance drift (ΔR/R0 = 2.35%), which is mainly affected by the oxygen vacancy concentration. This demonstrates that the film thermistors annealed in a hypoxia state will never be stable. This is because there will be several oxidation reactions leading to a continuous generation of cationic vacancies during high temperature aging. The present results will open a way to design desired stable negative temperature coefficient thermistors by adjusting the annealing oxygen atmosphere of films.

Low temperature growth and physical properties of InAs thin films grown on Si, GaAs and In0.53Ga0.47As template

Integration of III-V semiconductors on a Si platform is interesting for both nanoelectronic and optoelectronic devices. Among the different challenges, the formation of low resistive contacts remains essential. In this paper, the growth by metalorganic chemical vapor deposition of thin InAs film as intermediate layer between the III-V materials and the metal has been studied on different templates: Si(100), GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). We have shown that the formation of a continuous layer with low surface roughness is obtained at a growth temperature below 500°C with a two steps growth mode. The influence of the substrate on which the InAs is deposited, is investigated through morphological and structural properties. We observed an evolution of the InAs surface morphology versus the templates used. The surface roughness value obtained is 2.5nm, 0.9nm and 2nm respectively for a 30nm InAs layer grown on Si(100), GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). Structural characterization shows that InAs crystal quality is better when GaAs/Si(100) are used as templates compared to growth on Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). The n-type doping using silicon as impurity allows a doping level of 5×1019cm−3 for all InAs layers, which favors the formation of low resistance contacts. Moreover we measured aa minimum resistivity of 6×10−4Ω·cm−1 for InAs on Si(100) and 10−4Ω·cm−1 for InAs on GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100).