Showing papers on "Schottky barrier published in 2009"
TL;DR: It is found that bulk electric conduction in ferroelectric monodomain BiFeO3 crystals is highly nonlinear and unidirectional.
Abstract: Unidirectional electric current flow, such as that found in a diode, is essential for modern electronics. It usually occurs at asymmetric interfaces such as p-n junctions or metal/semiconductor interfaces with Schottky barriers. We report on a diode effect associated with the direction of bulk electric polarization in BiFeO3: a ferroelectric with a small optical gap edge of ∼2.2 electron volts. We found that bulk electric conduction in ferroelectric monodomain BiFeO3 crystals is highly nonlinear and unidirectional. This diode effect switches its direction when the electric polarization is flipped by an external voltage. A substantial visible-light photovoltaic effect is observed in BiFeO3 diode structures. These results should improve understanding of charge conduction mechanisms in leaky ferroelectrics and advance the design of switchable devices combining ferroelectric, electronic, and optical functionalities.
1,610 citations
TL;DR: By utilizing Schottky contact instead of Ohmic contact in device fabrication, the UV sensitivity of the ZnO nanowire nanosensor has been improved by four orders of magnitude, and the reset time has been drastically reduced.
Abstract: UV response of ZnO nanowire nanosensor has been studied under ambient condition. By utilizing Schottky contact instead of Ohmic contact in device fabrication, the UV sensitivity of the nanosensor has been improved by four orders of magnitude, and the reset time has been drastically reduced from 417 to 0.8 s. By further surface functionalization with function polymers, the reset time has been reduced to 20 ms even without correcting the electronic response of the measurement system. These results demonstrate an effective approach for building high response and fast reset UV detectors. © 2009 American Institute of Physics. DOI: 10.1063/1.3133358 Ultraviolet UV photon detectors have a wide range of applications from environmental monitoring, missile launching detection, space research, high temperature flame detection to optical communications. 1 For these applications, fast response time, fast reset time, high selectivity, high responsivity, and good signal-to-noise ratio are commonly desired characteristics. 2 For UV photon detector based on polycrystalline ZnO thin film, a slow response time ranging from a few minutes to several hours is commonly observed. 3,4 Due
540 citations
TL;DR: In this paper, the Schottky contact between PdAu top electrode and ZnO nanorod arrays was investigated and it was shown that the large work function of Pd and Au compared with the electron affinity of n-type ZnNO (naturally formed) and the minimum defect in ZnOs can occur.
Abstract: Figure S2. a) Fabrication procedure of the embossed flexible top electrode. b) FE-SEM imageof the embossed PdAu flexible top electrode Figure S3. Schottky contact between PdAu top electrode and ZnO nanorod arrays. Because of the large work function of Pd and Au compared with the electron affinity of n-type ZnO (naturally formed) and the minimum defect in ZnO, strong Schottky contact can occur.
404 citations
TL;DR: A new single nanowire based nanosensor is demonstrated for illustrating its ultrahigh sensitivity for gas sensing, which is 4 orders of magnitude higher than that obtained using an Ohmic contact device under the same conditions.
Abstract: A new single nanowire based nanosensor is demonstrated for illustrating its ultrahigh sensitivity for gas sensing. The device is composed of a single ZnO nanowire mounted on Pt electrodes with one end in Ohmic contact and the other end in Schottky contact. The Schottky contact functions as a "gate" that controls the current flowing through the entire system. By tuning the Schottky barrier height through the responsive variation of the surface chemisorbed gases and the amplification role played by the nanowire to Schottky barrier effect, an ultrahigh sensitivity of 32 000% was achieved using the Schottky contacted device operated in reverse bias mode at 275 °C for detection of 400 ppm CO, which is 4 orders of magnitude higher than that obtained using an Ohmic contact device under the same conditions. In addition, the response time and reset time have been shortened by a factor of 7. The methodology and principle illustrated in the paper present a new sensing mechanism that can be readily and extensively applied to other gas sensing systems.
234 citations
TL;DR: It is suggested that the Schottky barrier modulation at the contacts is the dominant mechanism from room temperature to 150 degrees C, and at higher temperatures, the charge transfer process contributes to the response signals.
Abstract: There has been an argument on carbon nanotube (CNT) based gas detectors with a field-effect transistor (FET) geometry: do the response signals result from charge transfer between adsorbed gas molecules and the CNT channel and/or from the gas species induced Schottky barrier modulation at the CNT/metal contacts? To differentiate the sensing mechanisms, we employed three CNTFET structures, i.e., (1) the entire CNT channel and CNT/electrode contacts are accessible to NH3 gas; (2) the CNT/electrode contacts are passivated with a Si3N4 thin film, leaving the CNT channel open to the gas and, in contrast, (3) the CNT channel is covered with the film, while the contacts are open to the gas. We suggest that the Schottky barrier modulation at the contacts is the dominant mechanism from room temperature to 150 °C. At higher temperatures, the charge transfer process contributes to the response signals. There is a clear evidence that the adsorption of NH3 on the CNT channel is facilitated by environmental oxygen.
230 citations
TL;DR: A nanowire-based nanosensor for detecting biologically and chemically charged molecules that is probe-free and highly sensitive is demonstrated and serves as a guideline for designing more practical chemical and biochemical sensors.
Abstract: A nanowire-based nanosensor for detecting biologically and chemically charged molecules that is probe-free and highly sensitive is demonstrated. The device relies on the nonsymmetrical Schottky contact under reverse bias, and is much more sensitive than the device based on the symmetric ohmic contact. This approach serves as a guideline for designing more practical chemical and biochemical sensors.
230 citations
TL;DR: In this article, the effect of postannealing on the electrical and optical properties of β-Ga2O3 photodiodes with a Au Schottky contact on a single crystal substrate was investigated.
Abstract: We fabricated β-Ga2O3 photodiodes with a Au Schottky contact on a single crystal substrate and investigated the effect of postannealing on the electrical and optical properties of the photodiodes. The ideality factor improved to near unity by annealing at temperatures above 200 °C; however, the reverse leakage current remained nearly unchanged. The responsivity in the wavelength region below 260 nm was enhanced dramatically by a factor of more than 102 after annealing at 400 °C resulting in maximum responsivity of 103 A/W, accompanied with a contrast ratio of about six orders of magnitude between the responsivities at 240 and 350 nm.
204 citations
TL;DR: In this paper, the growth of hexagonal ZnO nanotube arrays using a solution chemical method by varying the growth temperature (<100 °C), time and solution concentration was studied.
Abstract: We present a systematic study of the growth of hexagonal ZnO nanotube arrays using a solution chemical method by varying the growth temperature (<100 °C), time and solution concentration. A piezoelectric nanogenerator using the as-grown ZnO nanotube arrays has been demonstrated for the first time. The nanogenerator gives an output voltage up to 35 mV. The detailed profile of the observed electric output is understood based on the calculated piezoelectric potential in the nanotube with consideration of the Schottky contact formed between the metal tip and the nanotube; and the mechanism agrees with that proposed for nanowire based nanogenerator. Our study shows that ZnO nanotubes can also be used for harvesting mechanical energy.
183 citations
TL;DR: In this article, the Schottky barrier at the ZnO/Au interface blocks the electron transfer back to the dye and electrolyte, and thus increases the electron density at the conduction band.
Abstract: Vertically aligned zinc oxide (ZnO) nanorod arrays coated with gold nanoparticles have been used in Schottky barrier solar cells. The nanoparticles enhance the optical absorption in the range of visible light due to the surface plasmon resonance. In charge separations, photoexcited electrons are transferred from gold nanoparticles to the ZnO conduction band while electrons from donor (I−) in the electrolyte compensate the holes left on the gold nanoparticles. The fill factors of the dye-free Schottky barrier cell reach a value of ∼0.50. However, after incorporation of N719 sensitizing dye, the open circuit voltage increases to 0.63 V from 0.5 V being measured for dye-sensitized solar cells based on the bare ZnO nanorods. The Schottky barrier at the ZnO/Au interface blocks the electron transfer back from ZnO to the dye and electrolyte, and thus increases the electron density at the ZnO conduction band. The efficiency of the gold-coated ZnO nanorod dye-sensitized solar cells is thus increased from 0.7% to 1.2%.
177 citations
TL;DR: In this paper, an ultrathin interfacial silicon nitride layer was added to the metal/SiN/Ge Schottky diode to suppress strong Fermi level pinning, which resulted in effective control of Schotty barrier height.
Abstract: Schottky barrier height modulation in metal/Ge Schottky junction was demonstrated by inserting an ultrathin interfacial silicon nitride layer. The SiN interfacial layer suppressed strong Fermi level pinning in metal/Ge Schottky junction, which resulted in effective control of Schottky barrier height. Metal/SiN/Ge Schottky diode was systematically investigated in terms of SiN thickness dependence and metal work function dependence. At an optimal SiN thickness, Ohmic contact between metal and Ge was obtained as a result of Fermi level depinning, and almost ideal Schottky barrier height determined by the work function difference between the metal and Ge was achieved. This technology was finally applied to metal source/drain Ge metal-oxide-semiconductor field-effect-transistors with low source/drain resistance.
174 citations
TL;DR: In this paper, a possible mechanism for bipolar switching in a resistive switching cell in terms of electrochemical reactions involving oxygen ions/vacancies was proposed, which modulates the Schottky barrier height at the interface.
Abstract: We suggest a possible mechanism for bipolar switching in a $\text{Pt}/{\text{TiO}}_{2}/\text{Pt}$ resistive switching cell in terms of electrochemical reactions involving oxygen ions/vacancies. The electrochemical reactions are considered to take place at an interface between Pt and ${\text{TiO}}_{2}$ solid electrolyte, and they modulate the Schottky barrier height at the interface. Calculation results using this proposed mechanism can explain a bipolar switching behavior and semiquantitatively describe experimental data.
TL;DR: In this article, a wide band gap semiconducting layer of n-type ZnO thin film was fabricated on a Si substrate with electrochemical deposition technique and the currentvoltage (I-V) and capacitance-voltage/frequency (C-V/f) characteristics of the structure have been measured at room temperature.
TL;DR: In this paper, a flame detector was fabricated using a conductive single crystal substrate using a simple method without epitaxy and vacuum processes, which is a poly(3,4-ethylene dioxythiophene) complex with polystyrene sulfonic acid (PEDOT-PSS) Schottky contact/a semi-insulating layer of β-Ga2O3/n-type region of In ohmic contact.
Abstract: An oxide semiconductor of β-Ga2O3 has a natural solar-blind sensitivity due to its large bandgap of 4.8 eV. To evaluate its potential, a flame detector was fabricated using its conductive single crystal substrate applying a simple method without epitaxy and vacuum processes. The structure is a poly(3,4-ethylene dioxythiophene) complex with polystyrene sulfonic acid (PEDOT–PSS) Schottky contact/a semi-insulating layer of β-Ga2O3/n-type region of β-Ga2O3/an In ohmic contact. The spectral response of the detector exhibited a large 250-to-300-nm rejection ratio of 1.5 ×104 and an external quantum efficiency of 18% at 250 nm. The device successfully detected a flame by distinguishing 1.5 nW/cm2 solar-blind light from the flame under a strong fluorescent lamp illumination without any visible-cut filters. This result encourages the fabrication of practical β-Ga2O3-based flame detectors.
Patent•
31 Mar 2009TL;DR: In this paper, two fluorine ion containing regions are formed directly underneath both Schottky contacts in the rectifier and in the HEMT, pinching off the (electron gas) channels in both structures at the hetero-interface between the epitaxial layers.
Abstract: Integrated high efficiency lateral field effect rectifier and HEMT devices of GaN or analogous semiconductor material, methods for manufacturing thereof, and systems which include such integrated devices. The lateral field effect rectifier has an anode containing a shorted ohmic contact and a Schottky contact, and a cathode containing an ohmic contact, while the HEMT preferably has a gate containing a Schottky contact. Two fluorine ion containing regions are formed directly underneath both Schottky contacts in the rectifier and in the HEMT, pinching off the (electron gas) channels in both structures at the hetero-interface between the epitaxial layers.
TL;DR: In this paper, the authors demonstrate electrical injection and detection of spin-polarized electrons in silicon (Si) using epitaxially grown Fe_3Si/Si Schottky-tunnel-barrier contacts.
Abstract: We demonstrate electrical injection and detection of spin-polarized electrons in silicon (Si) using epitaxially grown Fe_3Si/Si Schottky-tunnel-barrier contacts. By an insertion of a delta-doped n^+-Si layer (~ 10^19 cm^-3) near the interface between a ferromagnetic Fe_3Si/Si contact and a Si channel (~ 10^15 cm^-3), we achieve a marked enhancement in the tunnel conductance for reverse-bias characteristics of the Fe_3Si/Si Schottky diodes. Using laterally fabricated four-probe geometries with the modified Fe_3Si/Si contacts, we detect nonlocal output signals which originate from the spin accumulation in a Si channel at low temperatures.
Book•
16 Nov 2009
TL;DR: In this paper, the authors introduce the concept of two-terminal transistors and their application in the measurement of TFTs, and propose a two-dimensional approach for the determination of the mobility of the TFT.
Abstract: Preface. 1 General concepts . 1.1 Introduction. 1.2 Conduction mechanism. 1.3 Chemistry and the energy diagram. 1.4 Disordered materials and the Meyer-Neldel Rule. 1.5 Devices. 1.6 Optoelectronics/photovoltaics. 2 Two-terminal devices: DC current . 2.1 Conductance. 2.2 DC current of a Schottky barrier. 2.3 DC measurements. 3 Two-terminal devices: Admittance spectroscopy . 3.1 Admittance spectroscopy. 3.2 Geometrical capacitance. 3.3 Equivalent circuits. 3.4 Resistor SCLC. 3.5 Schottky diodes. 3.6 MIS diodes. 3.7 MIS tunnel diode. 3.8 Noise measurements. 4 Two-terminal devices: Transient techniques . 4.1 Kinetics: Emission and capture of carriers. 4.2 Current transient spectroscopy. 4.3 Thermally stimulated current. 4.4 Capacitance transient spectroscopy. 4.5 Deep-level transient spectroscopy. 4.6 Q-DLTS. 5 Time-of-flight . 5.1 Introduction. 5.2 Drift transient. 5.3 Diffusive transient. 5.4 Violating einstein's relation. 5.5 Multi-trap-and-release. 5.6 Anomalous transients. 5.7 High current (space charge) transients. 5.8 Summary of the ToF technique. 6 Thin-film transistors . 6.1 Field-effect transistors. 6.2 MOS-FET. 6.3 Introducing TFTs. 6.4 Basic model. 6.5 Justification for the two-dimensional approach. 6.6 Ambipolar materials and devices. 6.7 Contact effects and other simple nonidealities. 6.8 Metallic contacts in TFTs. 6.9 Normally-on TFTs. 6.10 Effects of traps. 6.11 Admittance spectroscopy for the determination of the mobility in TFTs. 6.12 Summary of TFT measurements. 6.13 Diffusion transistor. Appendix A A Derivation of Equations (2.21), (2.25), (6.95) and (6.101) . Bibliography . Index.
TL;DR: In this article, the role of the Schottky contact and carrier detrapping from deep levels in the polarization mechanism was analyzed. But the role was not discussed. And the authors did not consider the role in the degradation of detection performance.
Abstract: Schottky CdTe nuclear detectors are affected by bias-induced polarization phenomena when operating at room temperature. A space charge buildup occurs at the blocking contact causing the degradation in detection performance. By means of Pockels effect, we study the electric field distribution inside the detector and its variation with time and temperature. The analysis of the space charge has allowed us to point out the role of the Schottky contact and of carrier detrapping from deep levels in the polarization mechanism. Moreover, measured current transients have been quantitatively accounted for by the increase in the electric field at the blocking junction.
TL;DR: A silicon-based Schottky contact photodetector integrated into a finite width asymmetric metal stripe supporting short-range surface plasmon polaritons is presented in this article.
Abstract: A silicon-based Schottky contact photodetector integrated into a finite width asymmetric metal stripe supporting short-range surface plasmon polaritons is presented. Input optical energy is coupled into a bound mode supported by the stripe, leading to total absorption of in-coupled energy. The absorbed energy excites carriers in the metal stripe, some of which cross the Schottky barrier (internal photoemission) leading to a photocurrent under reverse bias. Significant enhancement in the quantum efficiency is observed for a thin metal stripe due to multiple internal reflections of excited carriers. The device holds promise for short-reach high-speed optical interconnects and silicon-based photonic circuitry.
TL;DR: Electronic transport measurements in individual Au-catalyst/Ge-nanowire interfaces demonstrating the presence of a Schottky barrier are presented and the small-bias conductance density increases with decreasing diameter.
Abstract: We present electronic transport measurements in individual Au-catalyst/Ge-nanowire interfaces demonstrating the presence of a Schottky barrier. Surprisingly, the small-bias conductance density increases with decreasing diameter. Theoretical calculations suggest that this effect arises because electron-hole recombination in the depletion region is the dominant charge transport mechanism, with a diameter dependence of both the depletion width and the electron-hole recombination time. The recombination time is dominated by surface contributions and depends linearly on the nanowire diameter.
TL;DR: In this article, degradation of lattice-matched unpassivated InAlN/GaN high-electron-mobility transistors (HEMTs) was analyzed by measuring the drain current, a threshold voltage, a Schottky contact barrier height, a gate leakage and an ideality factor, an access, and an intrinsic channel resistance.
Abstract: We address degradation aspects of lattice-matched unpassivated InAlN/GaN high-electron-mobility transistors (HEMTs). Stress conditions include an off-state stress, a semi-on stress (with a partially opened channel), and a negative gate bias stress (with source and drain contacts grounded). Degradation is analyzed by measuring the drain current, a threshold voltage, a Schottky contact barrier height, a gate leakage and an ideality factor, an access, and an intrinsic channel resistance, respectively. For the drain-gate bias < 38 V parameters are only reversibly degraded due to charging of the pre-existing surface states. This is in a clear contrast to reported AlGaN/GaN HEMTs where an irreversible damage and a lattice relaxation have been found for similar conditions. For drain-gate biases over 38 V InAlN/GaN HEMTs show again only temporal changes for the negative gate bias stresses; however, irreversible damage was found for the off-state and for the semi-on stresses. Most severe changes, an increase in the intrinsic channel resistance by one order of magnitude and a decrease in the drain current by similar to 70%, are found after the off-state similar to 50 V drain-gate bias stresses. We conclude that in the off-state condition hot electrons may create defects or ionize deep states in the GaN buffer or at the InAlN/GaN interface. If an InAlN/GaN HEMT channel is opened during the stress, lack of the strain in the barrier layer is beneficial for enhancing the device stability.
TL;DR: In this article, the authors have compared resistance switching of NiO films deposited on Pt and SrRuO3 (SRO): unipolar switching in Pt/NiO/Pt and bipolar switching in P Pt and SRO/SRO, showing that on-and off-state conductions in unipolar switches are dominated by inductive Ohmic behavior and Poole-Frenkel effect.
Abstract: We have compared resistance switching of NiO films deposited on Pt and SrRuO3 (SRO): unipolar switching in Pt/NiO/Pt and bipolar switching in Pt/NiO/SRO. Linear fitted current-voltage curves and capacitance-voltage results show that on- and off-states conductions in unipolar switching are dominated by inductive Ohmic behavior and Poole–Frenkel effect, respectively. However, the conductions of on- and off-states in bipolar switching follow capacitive Ohmic behavior and Schottky effect, respectively. Therefore, we infer that the mechanisms of the unipolar and bipolar switching behaviors in NiO films are related with changes in bulk-limited filamentary conduction and interfacial Schottky barrier, respectively.
TL;DR: In this article, a separation of bulk and interface contributions to the electroforming and resistive switching behavior of Pt/STO(Fe)/Nb:STO devices by performing impedance spectroscopy was achieved.
Abstract: We succeeded in the separation of bulk and interface contributions to the electroforming and resistive switching behavior of Pt/STO(Fe)/Nb:STO devices by performing impedance spectroscopy. Two distinctive features observed in the impedance spectra could be assigned to the STO(Fe) bulk and to the depletion layer of the Pt/STO(Fe) Schottky contact. We attribute the resistance change during the dc forming process to a local bypassing of the depletion layer caused by oxygen effusion to the environment. By comparing the impedance spectra in the resistive “on” and “off” states, we propose that the resistance of the STO(Fe)/Nb:STO interface locally changes during the switching process.
IBM1
TL;DR: In this paper, the integration of rare-earth silicides, known to feature the lowest Schottky barriers (SBs) to electrons, coupled with a dopant segregation based on arsenic (As+) implantation was studied.
Abstract: As an attempt to considerably reduce the equivalent contact resistivity of Schottky junctions, this letter studies the integration of rare-earth silicides, known to feature the lowest Schottky barriers (SBs) to electrons, coupled with a dopant segregation based on arsenic (As+) implantation. Both erbium (Er) and ytterbium (Yb) have been considered in the implant-before-silicide (IBS) and implant-to-silicide flavors. It is shown that the two schemes coupled with a limited thermal budget (500degC) produce an SB below the target of 0.1 eV. The implementation of IBS arsenic-segregated YbSi1.8 junctions in an n-type SB-MOSFET is demonstrated for the first time resulting in a current-drive improvement of more than one decade over the dopant-free counterpart.
TL;DR: Deep level transient spectroscopy confirms the presence of native defects with discrete energy levels at GaN and provides support to this interpretation of lateral inhomogeneity of the SBH.
Abstract: The barrier heights (BH) of various metals including Pd, Pt and Ni on n-type GaN (M/n-GaN) have been measured in the temperature range 80–400 K with using a current–voltage (I–V) technique. The temperature dependence of the I–V characteristics of M/n-GaN have shown non-ideal behaviors and indicate the presence of a non-uniform distribution of surface gap states, resulting from the residual defects in the as grown GaN. The surface gap states density Nss, as well as its temperature dependence were obtained from the bias and temperature dependence of the ideality factor n(V,T) and the barrier height ΦBn(V,T). Further, a dependence of zero-bias BH Φ0Bn on the metal work function (Φm) with an interface parameter coefficient of proportionality of 0.47 is found. This result indicates that the Fermi level at the M/n-GaN interface is unpinned. Additionally, the presence of lateral inhomogeneities of the BH, with two Gaussian distributions of the BH values is seen. However, the non-homogeneous SBH is found to be correlated to the surface gap states density, in that Φ0Bn becomes smaller with increasing Nss. These findings suggest that the lateral inhomogeneity of the SBH is connected to the non-uniform distribution of the density of surface gap states at metal/GaN which is attributed to the presence of native defects in the as grown GaN. Deep level transient spectroscopy confirms the presence of native defects with discrete energy levels at GaN and provides support to this interpretation.
TL;DR: Nanocrystalline-nanoporous ZnO thin films were prepared by an electrochemical anodization method, and they showed better sensing performance compared to other noble metal contacts like Pt and Rh.
Abstract: Nanocrystalline-nanoporous ZnO thin films were prepared by an electrochemical anodization method, and the films were tested as methane sensors. It was found that Pd-Ag catalytic contacts showed better sensing performance compared to other noble metal contacts like Pt and Rh. The methane sensing temperature could be reduced to as low as 100°C by sensitizing nanocrystalline ZnO thin films with Pd, deposited by chemical method. The sensing mechanism has been discussed briefly.
TL;DR: In this article, sulfur (S) segregation was exploited to attain a record-low electron barrier height (PhiB N) of 110 meV for platinum-based silicide contacts.
Abstract: In this letter, sulfur (S) segregation was exploited to attain a record-low electron barrier height (PhiB N) of 110 meV for platinum-based silicide contacts. Sulfur-incorporated PtSi:C/Si:C contacts were also demonstrated in strained FinFETs with Si:C source/drain stressors. Incorporation of sulfur at the PtSi:C/Si:C interface in the source/drain regions of FinFETs provides a 51% improvement in external resistances and a 45% enhancement in drive current as compared to devices without S segregation. The remarkable reduction in PhiB N is explained using charge transfer and dipole formation at the silicide/semiconductor interface with S segregation.
TL;DR: In this paper, the currentvoltage characteristics of an organic bulk heterojunction solar cell have been modeled and compared with the measured characteristics of solar cell based on the blend of poly(3-hexylethiophene) (P3HT) and phenyl [6,6] C61 butyric acid methyl ester (PCBM).
Abstract: Current-voltage (J-V) characteristics of an organic bulk heterojunction solar cell have been modeled and compared with the measured characteristics of solar cell based on the blend of poly(3-hexylethiophene) (P3HT) and phenyl [6,6] C61 butyric acid methyl ester (PCBM). In an undoped organic double Schottky junction diode, for V
TL;DR: In this paper, a switchable rectifier built with Pt/TiOx/Pt was proposed and the reproducible rectification switching was demonstrated by changing the polarity of the pulse voltage, evidencing the excellent functionality of the engineered metal/oxide interface.
Abstract: The switchable rectifier built with Pt/TiOx/Pt was proposed and the reproducible rectification switching was demonstrated. The rectification switching is considered to be originated from the electrical control of the oxygen vacancy concentration at the interfaces between Pt and TiOx and resultant variations in the Schottky barrier height. The electrode area dependence of the current conduction after the rectification switching revealed that this switching occurs at the almost entire interface region. The reproducible switching in the Pt/TiOx/Pt rectifier is demonstrated by changing the polarity of the pulse voltage, evidencing the excellent functionality of the engineered metal/oxide interface.
TL;DR: In this paper, the Richardson constant and the mean barrier height were obtained as 167 A K - 2 cm - 2 and 061 EV in the temperature range 80-180 K, respectively.
Abstract: Temperature dependent current–voltage ( I – V ) and Hall measurements were performed on Pd/ZnO Schottky barrier diodes in the range 20–300 K The apparent Richardson constant was found to be 860 × 10 - 9 A K - 2 cm - 2 in the 60–160 K temperature range, and mean barrier height of 050 eV in the 180–300 K temperature range After barrier height inhomogeneities correction, the Richardson constant and the mean barrier height were obtained as 167 A K - 2 cm - 2 and 061 eV in the temperature range 80–180 K, respectively A defect level with energy at 012 eV below the conduction band was observed using the saturation current plot and ( 011 ± 001 ) eV using deep level transient spectroscopy measurements
TL;DR: In this article, the self-rectifying resistive switching characteristics are obtained when the resistive memory is switched to low-resistance state (LRS), and it is found that the Schottky contact at the Au/ZrO2 interface limits charge injection under reverse bias, while under forward bias the current is limited by space charge.
Abstract: The ZrO2 films with Au nanocrystals embedded (ZrO2:nc-Au) are fabricated by e-beam evaporation, and the self-rectifying effect in the Au/ZrO2:nc-Au/n+ Si sandwich structure is investigated. Self-rectifying resistive switching characteristics are obtained when the resistive memory is switched to low-resistance state (LRS). It is found that the Schottky contact at the Au/ZrO2 interface limits charge injection under reverse bias, while under forward bias the current is limited by space charge, resulting in a rectification of 7×102 under ±0.5 V at LRS, which enables the resistive memory to alleviate the cross-talk effect without additional switching elements in crossbar structure arrays. This self-rectifying resistive switching is believed to occur at a localized region and explained by a proposed model.