Schottky Diodes Research Articles

Carrier trapping in diamond Schottky barrier diode

Carrier trapping in a diamond Schottky barrier diode, consisting of a stack of a p− drift and p+ contact layer, is experimentally studied via subgap photocurrent measurements. In the measurements, trapped carriers are detected as an increment of the diode current under a probe light illumination in a near infrared range of 2.0 μm (0.62 eV). The density of trapped carriers is examined, and it is found to be sufficiently low, compared with that of free carriers, by an order of 105. Interestingly, the trapped carriers are observed only for the forward bias of the diode; they are not observed for the reverse bias. This suggests that the carrier trapping, yielding trapped carriers, originates from the valence band offset at the p−/p+ interface.

Isolation of a Cd-Based Coordination Polymer Containing Mixed Ligands: Time- and Temperature-Dependent Synthesis, Sulfonamide Antibiotics Detection, and Schottky Diode Fabrication.

In this study, we present a new cadmium(II)-based two-dimensional coordination polymer [Cd (L)(NA)(H2O)] (L = Iminol form of N-nicotinoyl glycinate, NA = nicotinate), 1, containing two linkers generated from N-nicotinoyl glycine. A comprehensive investigation was carried out during the synthesis of the coordination polymers by varying the reaction time interval and temperature, and it revealed the formation of three distinct phases, of which two phases were previously reported and one was a new compound (1). The structure of compound 1 was determined by single-crystal X-ray diffraction, and it shows a corrugated layer structure with hydrogen bond interactions leading to three-dimensional supramolecular arrangements. Compound 1 exhibited strong emission at 420 nm when excited at 260 nm in an aqueous medium. The emission behavior of this compound was used for the detection of various sulfonamide antibiotics, sulfadiazine, sulfamethazine, sulfachloropyridazine, sulfameter, sulfaquinoxaline, and sulfathiazole, in the presence of common water pollutants. The luminescence quenching response of compound 1 to sulfonamide antibiotics was significant, ranging from 81 to 94%, and the detection sensitivity reached parts per billion (ppb) levels (226-726 ppb). Compound 1 also used for the fabrication of Schottky diode devices with a barrier height of 0.86 eV along with an excellent ideality factor of 1.24.

1.43 kV GaN-based MIS Schottky barrier diodes

In this letter, we report on a quasi–vertical GaN-based metal–insulator–semiconductor (MIS) Schottky barrier diode (SBD) with an insertion of 2 nm thick Al2O3 dielectric layer. It shows a turn-on voltage of 0.7 V, a specific on-resistance of 3.5 mΩ·cm2, and a high on/off current ratio of 1011. The proposed structure enables a breakdown voltage of 1430 V, rendering a Baliga’s power figure-of-merit of 0.58 GW cm−2. The enhanced performance is attributed to defect-related leakage can be suppressed and the direct tunneling process dominates at the MIS-based Schottky contact interface.

Demonstration of vertical schottky barrier diodes based on α-Ga2O3 thin films enabled by corundum structured rh-ITO bottom electrodes

Demonstration of vertical schottky barrier diodes based on α-Ga2O3 thin films enabled by corundum structured rh-ITO bottom electrodes

Reliable electrical performance of β-Ga2O3 Schottky barrier diode at cryogenic temperatures

Electrical and trap characteristics of a large-size (2 × 2 mm2) β-Ga2O3 Schottky barrier diode (SBD) from 50 to 350 K have been reported. The ideality factor (n) decreases from 1.34 to nearly unity as temperature rises from 50 to 350 K, demonstrating near-ideal Schottky characteristics. The leakage current at cryogenic temperature (100 K) was significantly suppressed, indicating excellent off-state blocking performance at low temperatures. The weak temperature dependence of the carrier concentration (NS) and Schottky barrier height (ΦB) infers stable electrical characteristics of the β-Ga2O3 SBD. The stressed current density-voltage (J-V) and on-the-fly measurements reveal reliable dynamic performance under harsh low temperature conditions. Via deep-level transient spectroscopy, an electron trap, which is related to the dynamic performance instability and Lorentzian hump in low frequency noise spectra, is revealed for a β-Ga2O3 epilayer. The study reveals enormous potential of the utilization of a large-size β-Ga2O3 SBD for extreme temperature environments.

Embellished photosensitive Schottky barrier diode functionality of Ni(II)/Pb(II)-Salen complex with SCN− spacers: Insights from experimental and theoretical rationalization

This research article explores the synthesizing, structural characterizing, and photosensitive Schottky diode behaviour (PSBD) of one new hetero-nuclear Ni(II)/Pb(II)-Salen complex, [Ni2(L)Pb(μ-1,3-SCN)2(H2O)]2. The complex utilizes various analytical methods for characterization purposes, including single-crystal X-ray diffraction (SCXRD). Crystals have formed in the monoclinic space group P21/n within the compound. The complex asymmetric unit contains a deprotonated ligand (L2−), two Ni(II), one Pb(II), two SCN− ions, and Ni(II) metal coordination by H2O molecule. The crystallographic structure has octahedral and see-saw geometries around the Ni(II) and Pb(II) metal ions. The crystal structure reveals remarkable supramolecular interactions, with significant S⋯H contacts (13 %) evident from the Hirshfeld surface (HS) and 2-D fingerprint plots. The calculated optical band gap (3.14 eV) and UV–Visible measurement support the semiconductor behaviour. In addition, the compound shows electrical conductivity and photosensitivity (dark & light), suggesting potential applications in optoelectronic devices. The complex transports charge through space via a hopping process. The extensive experimental investigations indicate that exposure to visible light increases electrical conductivity compared to dark conditions, popularly known as PSBD behaviour. The complex conductivity function substantiates the DFT-based DOS, PDOS, and OPDOS plot analysis. Therefore, the heteronuclear complex has been successfully used in thin-film active devices despite technological challenges.

Peculiarities of current transport in boron-doped diamond Schottky diodes with hysteresis in current–voltage characteristics

The paper studies peculiarities of current transport in Au/Pt/Ni/diamond Schottky diodes with the hysteresis in current–voltage (I-V) characteristics and the nonlinear dependence of the barrier height φb on the applied voltage and proposes a method for determining basic parameters. Lateral diode structures were processed on boron-doped HPHT-diamond grown in the Fe-Al-B-C system and demonstrated barrier I-V characteristics with the exponential growth of the forward current of about eight orders of magnitude. It is shown that the voltage-dependent barrier height and hysteresis of the current-voltage characteristics can be explained by the presence of a thin dielectric gap at the metal-semiconductor interface and deep levels with lifetimes of the order of tens of seconds or more. Recharging of deep levels can significantly affect the parameters of the current-voltage characteristics. Three distinct regions were revealed. Excess current at zero voltage (region I) is related to deep-level recharge. Within regions II and III linear dependence of the φb on the applied voltage was observed. A linear dependence of the φb is related to the thermionic-field emission mechanism of current transport. Analysis of the temperature dependence I-V characteristics, capacitance-voltage (С-V) as well as frequency-capacitance (C-f) characteristics of arrays of HPHT diamond Schottky diodes yields information on the distribution of macro-defects, the state of the surface, and doping of the sub-surface region, which can be used for the improvement of the growth process and post-growth treatments for the development of diamond-based microelectronic devices.

A Review on Reverse-Bias Leakage Current Transport Mechanisms in Metal/GaN Schottky Diodes

A Review on Reverse-Bias Leakage Current Transport Mechanisms in Metal/GaN Schottky Diodes

Investigation of Terp-Pyr/p-Si diode using complex impedance spectroscopy depending on measurement temperatures and frequencies

A unique Al/Terp-Pyr/p-Si/Al diode structure that has not before been presented was introduced in this paper. Utilizing capacitance-conductance-frequency (C-G-f) characteristics in the frequency range of 20 Hz− 1.5 MHz for four temperatures of 300 K, 325 K, 350 K, and 375 K, admittance analysis was carried out to disclose the impedance and dielectric properties of the diode. The appearance of interface states at the Terp-Pyr/p-Si interface leads to an increase in capacitance values at low frequencies. Using complex impedance spectroscopy, the impedance characteristics of the Al/ Terp-Pyr/p-Si/Al Schottky diode were examined. The fabricated diode’s dielectric, modulus, and ac conductivity properties were investigated in the same frequency and temperature range. It has been revealed that while ϵ′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\epsilon }^{{\\prime }}$$\\end{document} decreases up to high frequencies for all temperatures, it grows with temperature in the low-frequency zone. It becomes apparent that while the real component (M’) of modulus grows for all temperatures from low to high frequencies, it decreases at high frequencies as temperature rises. remarkably adjustable temperature, voltage, and frequency tuning of the dielectric constants (ϵ′,ϵ′′)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$({\\epsilon }^{{\\prime }},{{\\epsilon }^{{\\prime }}}^{{\\prime }})$$\\end{document} and dielectric loss tangent (tanδ). Additionally, the equivalent circuit of the Al/ Terp-Pyr/p-Si/Al Schottky diode and Cole-Cole diagrams were explored.

Synthesis of Template-free Flower-like ZnO Nanorods using a Simple Chemical Bath Technique

Flower-like ZnO nanorods were successfully synthesised using a template-free, low-temperature chemical bath deposition method. The effects of growth time on the structural, morphological, and vibrational properties of flower-like zinc oxide were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicated that the crystallite size and density of flower-like ZnO nanorods increased with increasing growth time. Raman spectroscopy confirmed the existence of specific Raman modes that correspond to the wurtzite structure of ZnO. In addition, Raman measurements revealed that increased growth time increases the Raman modes intensity of the flower-like ZnO nanorods. Moreover, the measurements of the Au/ZnO nanorods/FTO Schottky diode showed that all devices functioned as Schottky diodes and rectifying; however, their ideality factor was greater than 1. In addition to the ideality factor, the Schottky barrier height was calculated and slightly increased with growth time. The values of Schottky barrier height obtained were 0.502 eV, 0.523 eV, 0.516 eV and 0.529 eV for samples grown at 1, 2, 3 and 4 h, respectively.

Electrical and optical performances investigation of planar solar blind photodetector based on IZTO/Ga2O3 Schottky diode via TCAD simulation

Electrical and optical performances investigation of planar solar blind photodetector based on IZTO/Ga2O3 Schottky diode via TCAD simulation

Self-rectifying resistive switching in MAPbI3-based memristor device

A critical stage in developing high-density memristors is addressing the sneak current within the crossbar architecture. One of the effective strategies to endow the memristive cell with the ability to prevent sneak currents when it is in a low resistance state is to give it an inherent diode, known as a self-rectifying memristive cell. This study demonstrates the Schottky diode inside the MAPbI3-based memristive cell, a consequence of its interaction with the tungsten (W) electrode. The performance of memory devices is reliable with low-voltage operation, a resistance window having over ten of magnitude, and the retention time remains over 104 s. Prominently, the self-rectifying behavior is sustainable over 150 cycles and exhibits a rectification ratio of approximately 102 times. Density functional theory calculation reveals the presence of unoccupied gap states on an interfaced MAPbI3 surface, serving as electron trapping states during the charge transport across the W/MAPbI3 Schottky interface. Consequently, the conduction mechanism is primarily governed by an interfacial-controlled model, notably Schottky emission. This improvement promises to eliminate sneak currents in future crossbar array fabrication.

Analytical assessment of Schottky diodes based on CdS/Si heterostructure: current, capacitance, and conductance analysis using TCAD

Analytical assessment of Schottky diodes based on CdS/Si heterostructure: current, capacitance, and conductance analysis using TCAD

β-Ga2O3 Schottky Barrier Diode with Ion Beam Sputter-Deposited Semi-Insulating Layer

Vertical Schottky barrier diodes based on an ion beam sputter (IBS)-deposited β-Ga2O3 film on a single-crystalline (2¯01) unintentionally doped (UID) β-Ga2O3 with a Ni contact were developed. To form ohmic Ti/Ni contacts, the IBS-Ga2O3/UID β-Ga2O3 structures were wet-etched, and an indium tin oxide (ITO) intermediate semiconductor layer (ISL) was deposited on the opposite surface of the UID β-Ga2O3. The IBS-deposited Ga2O3 layer was polycrystalline and semi-insulating. Low leakage currents, rectification ratios of 3.9 × 108 arb. un. and 3.4 × 106 arb. un., ideality factors of 1.43 and 1.24, Schottky barrier heights of 1.80 eV and 1.67 eV as well as breakdown voltages of 134 V and 180 V were achieved for diodes without and with ITO-ISL, respectively. The surface area of the IBS-Ga2O3 film acted as a thin dielectric layer and, together with the preliminary wet etching, provided low leakage currents and relatively high Schottky barrier heights. Diodes with a Schottky barrier based on a Ni/IBS-deposited Ga2O3 film contact were demonstrated for the first time.

Fully-vertical GaN-on-SiC Schottky barrier diode with ultrathin AlGaN buffer layer

In this letter, vertically conductive GaN epilayer on SiC substrate was achieved without the typically used conductive buffer layer. Here, in order to reduce the impacts of band offset of different layers on vertical conductivity and improve the vertical carrier transportation, an ultrathin AlGaN buffer layer was employed to replace the thick conductive buffer layer. Fully-vertical Schottky barrier diode (SBD) based on this vertically conductive epi-stack demonstrated a much lower specific on-resistance of 0.84 mΩ·cm2 with superior thermal stability. Moreover, the SBD also exhibited an on/off ratio of ∼5 × 109 and a nearly unity ideality factor of 1.08. This approach lays the foundation for the heterogeneous integration of GaN/SiC based devices.

An Expansion of Polarization Control Using Semiconductor-Liquid Junctions.

This report examines the concept of independent control over current and applied potential in electrocatalysis, as a means of improving control over product selectivity. Previous work, while permitting separate modulation of current and potentiostat bias, precluded independent control over the current flow and applied cell potential. This study seeks to resolve that limitation by exploiting the Schottky diode behavior inherent to semiconductor-electrolyte interfaces. Light is explored as a prospective second degree of freedom for controlling polarization in a suitably designed, photoelectrochemical (PEC) device, enabling the arbitrary selection of current with respect to an applied cell potential. In contrast to metal electrodes, the property of light-dependent carrier concentrations in semiconductors forms the operative means of controlling charge fluxes at some arbitrary applied potential in PEC devices featuring a semiconductor-liquid junction. This functionality enables exploration of polarization states distinct from those accessible with a dark cell, with implications for improved control over electrochemical reactions.

A simulation study of vertical Ga2O3 Schottky barrier diodes using field plate termination

The precision design of beta-phase gallium oxide (β-Ga2O3) power devices requires appropriate physical properties, including a breakdown electric field intensity. To clarify the breakdown electric field in β-Ga2O3, we fabricated vertical Schottky barrier diodes (SBDs) with a field plate (FP) on a β-Ga2O3 (001) epitaxial layer and simulated their breakdown situations under reverse bias. The calculated breakdown voltages of the SBD with a single FP were consistent with the experimental values when assuming an electric field criterion of 5 MV cm−1 in β-Ga2O3. By designing a SBD with a double FP according to the electric field criterion above, a breakdown voltage over 2 kV and specific on-resistance of 6.9 mΩ cm2 were realized simultaneously. This results in an electric field criterion that is useful for the design parameter of β-Ga2O3 devices to balance a high breakdown voltage and low on-resistance.

Bottom-up vertical GaN nanocolumn Schottky barrier diodes with extremely high packing density grown by molecular beam epitaxy

In this paper, we report achieving extremely high-density packing in high-voltage vertical gallium nitride (GaN) nanocolumn Schottky barrier diodes (NC-SBDs) through the adoption of a bottom-up process. The NC-SBDs were formed via epitaxial growth using Titanium-mask selective area growth (Ti-SAG) by rf-plasma-assisted MBE (rf-MBE), realizing a packing density equivalent to exceeding 10 million columns/mm2. Our fabricated NC-SBDs with a period of 300 nm, a diameter of 250 nm, and a drift length of 1.3 μm demonstrated a breakdown voltage (BV) of 260 V with an on-resistance of 2.0 mΩcm2, yielding an excellent figure of merit of 33.8 MW/cm2 for nanocolumn-based high-voltage devices. We also discuss dielectric reduced surface field effect and impurities within the nanocolumns as potential factors contributing to the achievement of higher BV devices.

Graphene/Al2O3/Si Schottky diode with integrated waveguide on a silicon-on-insulator wafer

Graphene/Al2O3/Si Schottky diode with integrated waveguide on a silicon-on-insulator wafer

Design and simulation of high performance β-Ga2O3 super barrier rectifier with a current blocking layer

In this work, a β-Ga2O3 super barrier rectifier with a current blocking layer (CSBR) is proposed. Its static characteristics, dynamic characteristics and surge capability are investigated by TCAD simulation. The Baliga’s figure of merit (BFOM) can reach 1.62 GW cm−2 with the on-resistance of 3.68 mΩ cm−2 and the breakdown voltage of 2447 V, exhibiting excellent performance. Foremost, the turn-on and turn-off of the device is controlled by metal-oxide-semiconductor (MOS) structure. The reverse recovery time is 11.2 ns, which is compatible with that of a Schottky diode. Simulation results show that the dimensions of the cells and the proportion of the ohmic contact region in the cells are the key parameters affecting the reverse recovery time. In addition, the CSBR with double-side cooling configuration demonstrates high surge capability. It can sustain a peak surge current density of 5000 A cm−2, which is more than 10 times its forward current (V Forward = 3.0 V). Overall, the proposed structure has a high BFOM, excellent reverse characteristics and high reliability, demonstrating its potential in high voltage applications. Moreover, CSBR can be embedded into Ga2O3-MOSFET as a free-wheeling diode.