Schottky-type Diodes Research Articles

Self-assembly monolayer impact on Schottky diode electrical properties

This study examines the electrical and charge transport properties of p-Si/TiO2/self-assembly monolayer (SAM)/Al type Schottky diodes. The diodes were fabricated by applying the SAM molecule 4′-[(3-methylphenyl)(phenyl)amino]biphenyl-4-carboxylic acid (CT21) onto titanium dioxide (TiO2) synthesized via the sol-gel method. The key parameters, including the ideality factor (n), series resistance (Rs), and barrier height (∅b), were used to assess the impact of CT21 on diode performance. Experimental results revealed that using CT21 at the TiO2/Al interface significantly enhances diode performance. The n decreased from 3.8 in the control diode to 1.9 with CT21. Rs was substantially reduced, and the ∅b increased. The rectification ratio improved from 1x104 in the control diode to 1.1x105 in the CT21-modified diode. These enhancements, due to the CT21 molecule's ability to reduce interface states (Nss) and improve surface properties, underscore the potential of SAM coatings to open a new window in nanoelectronics with better performance and reliability.

Frequency-dependent capacitance and conductance characteristics and current transport mechanisms of Schottky diodes with TPA-IFA organic interfacial layer

In this study, a Schottky barrier diode with an Al/TPA-IFA/p-Si structure was fabricated using spin coating and thermal evaporation methods. Using forward and reverse bias I–V measurement, we examined the key electrical characteristics of the Al/TPA-IFA/p-Si diode, including Φb, n, Rs, and Nss; we also estimated VD, NA, EF, ∆Φb, WD, Φb and Nss using C–V measurements under the different frequencies (10, 50, 100, 500 kHz, and 1 MHz) at room temperature. Using I–V data and the Thermionic Emission (TE) theory, basic electrical parameters such as ideality factor ( n ), and barrier height ( Φb ) values were computed as 3.01 and 0.716 eV. The fundamental diode parameters are highly frequency-dependent. It was also found that the series Resistance ( Rs ) values reduced with increasing frequency, but the barrier height ( Φb ) and the width of the depletion layer ( WD ) increased. It was found that when frequency increased, the diode capacitance reduced for our new Schottky-type diode. The diode’s potential conduction mechanisms were examined through the utilization of reverse lnI−V0.5 and forward lnI−V graphs. The transport properties of Al/TPA-IFA/p-Si diode are primarily governed by ohmic conduction, Space Charge Limited Current (SCLC), and Trap Charge Limited Current (TCLC) mechanisms at low, moderate, and high voltages, respectively. It was concluded that the Poole–Frenkel Emission (PFE) mechanism was dominant for the Al/TPA-IFA/p-Si diode. Ultimately, the findings confirmed that the TPA-IFA-based diode could be obtained for the electronic application.

Aggregation−induced red−shift emission from self-assembled planar naphthalene diimide dye: Interlayer in a Schottky-type photodiode and DFT studies

In this study, a planar, soluble, thin film-forming and self-assembled small naphthalene diimide (3) molecule with a subtle moiety at the imide-nitrogen was synthesized, and applied for the first time in literature as an interfacial layer between Al and p-Si layers in a Schottky-type photodiode. The morphology of the compound was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thin film structure and morphology affected the optical and electrical properties. The energy levels of the highest occupied molecular orbitals and lowest unoccupied molecular orbitals of 3 were calculated as −6.14 eV and −4.02 eV, corresponding to the band gap of 2.12 eV consistent with density functional theory (DFT) results. Differential scanning calorimetry (DSC) studies revealed a relatively high Tg value at 208 °C, indicating high-temperature applicability of the crystalline structure. The I–V measurements of Al/3/p-Si heterostructure were performed under dark and various light power intensities. The current steadily rose with each incremental 20 mW increase in light intensity. The reverse current increased almost 10-fold at 100 mW/cm2 illumination compared to dark measurement. The photodiode's responsivity, photosensitivity, and detectivity factors were elucidated. The photodiode's characteristic values, such as Io, n, ϕb, and Rs, were obtained as 3.50 × 10−6 A, 8.24, 0.588 eV and 2.266 kΩ, respectively. The fabricated Schottky-type diode showed promising results for the optoelectronic field. The compound's perfect solubilities in a wide range of solvents, processability, excellent chemical and photochemical stabilities, and exciting optical, thermal and electrochemical properties make it an ideal candidate for thin film and molecular electronics applications.

A comparison electrical characteristics of the Au/(pure-PVA)/n-Si and Au/(CdTe doped-PVA)/n-Si (MPS) type Schottky structures using I–V and C–V measurements

In this study, both the Au/(pure-PVA)/n-Si (MPS-1) and Au/(CdTe:PVA)/n-Si (MPS-2) type Schottky diodes (SDs) were fabricated onto the same n-Si wafer in same conditions. After that, their electrical parameters were obtained from the current–voltage (I–V) and capacitance–voltage (C–V) measurements and compared to each other to determine the effect (CdTe:PVA) interlayer on the performance of MPS type SD. The saturation current (Is), ideality factor (n), rectification ratio (RR = Ifor./Irev.), zero-bias barrier height (ΦBo), and series/shunt resistances (Rs, Rsh) were derived utilizing I–V data. The values of Io, n, and ΦBo were found as 9.13 × 10–7 A, 11.07, 0.63 eV for MPS1 and 1.54 × 10–10 A, 3.97, 0.85 eV for MPS2, respectively. The C−2–V graphs were drawn for 0.7 MHz to obtain the doping concentration of donor atoms (ND), Fermi energy (EF), BH/(ΦB(C–V)), depletion layer width (WD), and maximum electric field (Em). The Nss − (Ec − Ess) profile for two SDs was produced from the I–V data by considering the voltage dependence of n and BH. The values of surface states (Nss) were changed between 4.8 × 1013 and 1.7 × 1014 eV−1 cm−2 for MPS1 and 5 × 1012 and 1.15 × 1013 eV−1 cm−2 for MPS2, respectively. All experimental results show that the (CdTe:PVA) interlayer significantly improved the quality of the MS type SDs rather than (pure-PVA) in terms of lower values of leakage/saturation current, n, Nss, and higher RR, BH, and Rsh when compared (pure-PVA) interlayer. The (CdTe:PVA) interlayer may be used instead of the conventional interlayer in the future.

The influence of the physicochemical processes on the electrical response of Al/p-Si structure with etched surface

In this paper, the electrochemical etching process is used for surface modification of the p-Si wafer, named as porous silicon (PS), in the metal–semiconductor (MS) type Schottky diode (SD) with a structure of Al/p-Si. Five regions of PS wafer with different etching rates are selected for comparison of them which are called P2, P3, P4, and P5 (P1 is the reference area without porosity). The morphological, structural, and electrical properties of the PS used in the MS-type SD are investigated using field-emission scanning electron microscope (FE-SEM) images, energy dispersive X-ray (EDX) analysis, and current–voltage (I–V) characteristics, respectively. The FE-SEM images show a meaningful effect on the porosity. The EDX spectrum demonstrates the importance of the chemical effects in addition to the physical changes in the porosity process of the p-Si wafer. The reverse-saturation current (I0), ideality factor (n), barrier height at zero-bias (ΦB0), and series/shunt electrical resistances are also computed and compared. Some of these parameters (n, Rs, BH) are determined using different methods, namely Thermionic emission (TE), Cheung functions, and modified Norde, and they exhibit strong agreement with each other. The energy-dependent profiles of surface states (Nss) are estimated from the I–V data by considering the voltage dependence of ΦB (V) and n(V). All the experimental findings indicate that the etching process of the p-Si wafer significantly influences the electrical performance of the Al/p-Si Schottky diode by increasing the extent of etching.

Dependence of diode behaviour and photoresponse of Ga-doped ZnO (GZO)/p-Si junction on the carrier concentration of GZO layer

Ga-doped ZnO (GZO)/p-Si junctions were fabricated by reactive co-sputtering of Zn-GaAs target in Ar–O2 atmosphere. Highly degenerate GZO (carrier concentration ∼1021 cm−3) deposited at 4 % O2 forms non-rectifying contact with p-Si. GZO/p-Si diodes fabricated with moderately doped GZO layers deposited at 5 % O2, having carrier concentration ∼1019 cm−3 display low turn-on voltage (≲ 0.5 V) and ideality factor ≈ 2. Measurement of barrier height by temperature dependent I–V and built-in potential by C–V reveal respective values of (0.74 ± 0.07 eV) and (0.44 ± 0.04 eV), suggesting formation of Schottky type diodes. These diodes display nearly linear I–V characteristics under UV illumination, yielding photoresponsivity ∼1 A/W at ± 1 V. In contrast, GZO/p-Si diodes fabricated with lightly doped (non-degenerate) GZO layers deposited at 6–8 % O2, having carrier concentration ∼1018 cm−3, show higher turn-on voltages (4.5–6.5 V) and ideality factors of 2.5–2.7. I–V and C–V measurements reveal nearly equal values of barrier height and built-in potential, indicating formation of n-p heterojunctions, with near-elimination of conduction band discontinuity. Under UV illumination, I–V characteristics of these GZO/p-Si diodes display non-linear behaviour in forward bias and yield photoresponsivity of ∼0.1 A/W at ±1 V.

Comparison of the electrical and impedance properties of Au/(ZnOMn:PVP)/n-Si (MPS) type Schottky-diodes (SDs) before and after gamma-irradiation

The effect of 60Co-iradiation) on the electrical parameters in the Au/(ZnOMn:PVP)/n-Si SDs have been investigated using the current-voltage (I–V) and capacitance/conductance-voltage (C/G–V) measurements. Firstly, the values of reverse-saturation-current (Io), ideality-factor (n), barrier-height (BH), shunt/series resistances (Rsh, Rs), and rectifying-rate (RR) were extracted from the I–V data before and after gamma-irradiation (5 and 60 kGy) using thermionic-emission (TE), Norde, and Cheung methods. The surface-states (Nss) versus energy (Ec–Ess) profile was extracted from I–V data considering voltage-dependent of n and BH using Card-Rhoderick method. Secondly, the doping-donor atoms (Nd), Fermi-energy (EF), BH, maximum electric-field (Em), and depletion-layer width (Wd) were extracted from the linear-part of reverse-bias C−2–V plot for 100 kHz before and after irradiation. Finally, the voltage-dependent profiles of Rs and radiation-induced of Nss were extracted from the C/G–V plots by using Nicollian-Brews and the difference between C–V plots before and after irradiation, respectively. The peak behavior in the Nss–V plots and shifts in its position was attributed to special-distribution of Nss at (ZnOMn:PVP)/n-Si interface and restructure/reordering of them under radiation and electric field. Experimental results show that gamma-irradiation is more effective both on the I–V and C/G–V plots or electrical parameters, and hence the fabricated Au/(ZnOMn:PVP)/n-Si SDs can be used as a radiation-sensor.

Silicon carbide of 4H-SiC type Schottky diode current-voltage characteristics in small-sized type metal-polymeric package SOT-89

The forward and reverse current–voltage characteristics of Ti/Al/4H-SiC Schottky diode type DDSH411A91 in modern small-sized (SOT-89) type metal-polymeric package have been obtained. In forward direction (current up to 2 A) on the basis of analysis it is shown that Schottky diode corresponds to the "ideal" diode with ideality factor n=1.12 and effective Schottky barrier height φB =1.2 eV. It is shown that reverse current-voltage characteristics (breakdown voltage 1200 V) can be well approximated by mechanism of field dependence of barrier height lowering by the presence of the intermediate layer in the form of oxide on the 4H-SiC surface.

Improving the electrical properties of TiOx Schottky-type diode with an extra ZrO2 insulating layer

Titanium oxide has been considered a promising candidate for Schottky-type diode application. In this paper, an alternative approach for improving electrical properties of TiO[Formula: see text]-based Schottky-type diode has been demonstrated. Compared with the Ag/TiO[Formula: see text]/Ti structure Schottky-type diode, by embedding an extra ZrO2 insulating layer between the Ag/TiO[Formula: see text] interface, an extremely high rectifying ratio of 109 can be obtained in the Ag/ZrO2/TiO[Formula: see text]/Ti structure device. The improvement of the electrical properties in the Ag/ZrO2/TiO[Formula: see text]/Ti structure device can be attributed to the localized formation of Ag metal conductive filaments in ZrO2 layer after switching on.

Evaluation of gamma-irradiation effects on the electrical properties of Al/(ZnO-PVA)/p-Si type Schottky diodes using current-voltage measurements

In this study, Al/(ZnO-PVA)/p-Si (MPS) type Schottky diodes (SDs) were produced and the radiation effects on their electrical properties were investigated using the current-voltage (I–V) measurements. The I–V measurements were performed before irradiation and after various irradiation doses in the wide voltage range (±4 V) at room temperature. To determine gamma-irradiation effects on the MPS-type SDs accurately, one SD was preferred as a sample, and its significant electrical parameters such as zero-bias barrier height (ΦB0), ideality factor (n), and reverse-saturation-current (I0) were calculated using the linear parts of the ln(I)–V characteristics. Besides, to observe the effects of gamma-rays on MPS-type SDs in different voltage regions, some diode parameters were obtained by different calculation methods such as Cheung and Norde functions as well as Thermionic Emission (TE) theory. The calculations showed that high doses of gamma-irradiation (>5 kGy) caused the annealing effect, which leads to an improvement in some electrical parameters of SD, especially in the high electric field region. On the other hand, the energy distribution of the surface states (Nss) was obtained by utilizing the voltage-dependent ideality factor and the effective barrier height, with and without considering the series resistance (Rs) effect. It was observed that Nss values decreased almost as exponentially from the mid-band gap of the semiconductor towards the upper edge of the valance-band. Also, the density of surface states decreased with increasing radiation doses. As a result, almost all diode parameters are affected by irradiation. However, no significant defect has been detected that would affect the stable operation of the diode. Hence, Al/(ZnO-PVA)/p-Si type SD can be used as an MPS-type detector instead of MIS/MOS-type detectors due to some advantages of the organic/polymer interlayer such as being cheap, light per molecule, flexible and requiring low energy consumption.

Modification of Schottky barrier height using an inorganic compound interface layer for various contact metals in the metal/p-Si device structure

In this study, lithium fluoride (LiF) was employed as an interface material by thermal evaporation technique and its effect of on basic device parameters such as Schottky barrier height and ideality factor was examined for different contact metals. In the device fabrication process, the aluminum (Al) metal was used only as the ohmic contact for all devices while Al, gold (Au), chromium (Cr) and nickel (Ni) were employed as Schottky contacts. The reference device structures were also fabricated without the LiF interfacial layers to better understand the effect of the interfacial layer. Thus, the metal/p-Si/Al and metal/LiF/p-Si/Al Schottky type device structures were obtained by using p type silicon (Si) wafer and Al, Au, Cr, Ni for top metal contacts to investigate the effect of these metals on the device parameters. The electrical measurements of the reference samples and Au/LiF/p-Si/Al, Al/LiF/p-Si/Al, Cr/LiF/p-Si/Al, Ni/LiF/p-Si/Al Schottky type diode structures were characterized by current–voltage (I–V) measurements at the room temperature and dark. Basic diode parameters such as ideality factor (n) and barrier height (Φb) of eight Schottky devices were calculated by the thermionic emission (TE) theory, Cheung and Norde functions at room temperature. The results revealed that the LiF interface material caused an increase in the barrier height (BH) compared to the reference device. This increase in the BH values of the devices in accordance with their reference samples was different for Al, Au, Cr, and Ni metals. In the calculation made by TE theory, the LiF interface increased the BH of the Al/LiF/p-Si device from 0.69 to 0.78, while increasing the BH of the Ni/ LiF/p-Si device from 0.57 to 0.65. The obtained results highlighted that the work function of Schottky metals and interface material are effective in modulating the BH of the device. In addition, I–V measurements of the AI/LiF/p-Si/Al device were taken under light and the results obtained showed that this device can be used in photodiode applications.

DV/dt testing of high voltage 4H-SiC Schottky diodes with different types of metal-polymeric packages

The dV/dt values for 4H-SiC Schottky type diodes with different type packages have been determined experimentally. It is determined that experimental dV/dt values for 4H-SiC Schottky type diodes in metal-polymeric packages (SOT-89, QFN, PQFN, TO-220) are varying in interval of 645¸1103 V/ns. It is established that the dV/dt dependence on maximal amplitude of reverse voltage demonstrate nonlinear character (close to parabolic dependence) for all studied SiC Schottky type diodes in different type packages.

A Highly Sensitive Temperature Sensor Based on Au/Graphene-PVP/n-Si Type Schottky Diodes and the Possible Conduction Mechanisms in the Wide Range Temperatures

We report that the sensitive temperature response and possible Conduction Mechanisms (CMs) of Au/graphene-PVP/ ${n}$ -Si type Schottky diodes (SDs) are investigated using the standard Thermionic Emission (TE) theory at low temperatures (LTs) and high temperatures (HTs). The obtained results indicate that the zero-apparent barrier height ( $\phi _{\textit {Bo}}$ - $\phi _{\textit {ap}}$ ) increases while the ideality factor ( ${n}$ ), series and shunt resistances ( ${R} _{s}$ , ${R} _{\textit {sh}}$ ), rectifying rate (at ±2V) and surface states ( ${N} _{\textit {ss}}$ ) decrease with increasing temperature. The $\phi _{\textit {Bo}}$ , ${n}$ and ${R} _{s}$ values are also extracted from Cheung’s functions and, then compared with those obtained TE theory. The conventional Richardson plot ( $\ell {n}$ ( ${I} _{o}$ /T 2)- q/kT ) displays the deviation from the linearity at low-temperatures ( $T\le140$ K). Besides, the experimental value of Richardson constant ( ${A} ^{\ast }$ ) deduced from the intercept of plot was found to be several orders lower than the theoretical value. The discrepancies and higher values for the parameter of ${n}$ are important evidences for the deviation from TE theory. This is mainly attributed to the spatial inhomogeneities of the barrier height and potential fluctuations at the interface including low/high barrier areas. Hence the CMs across diode preferentially flows through these lower barriers/patches at the regions of LTs. The decrement in the ${N} _{\textit {ss}}$ with the enhancement in the temperature is in relation to the molecular restructuring-reordering under temperature and voltage effects. The SDs fabricated with graphene-PVP interlayer exhibit a higher sensitivity ( ${S}$ ) rather than many silicon/SOI-based structures. Numerically, the ${S}$ values are found to be in a range of 1.3 mV/K (LTs)/−1.93mV/K (HTs) in case of ${I} =0.1\,\,\mu \text{A}$ as against much greater values of −8.2 mV/K (LTs)/−7.9mV/K (HTs) for ${I} = 10\,\,\mu \text{A}$ .

Determination of dV/dt and dI/dt characteristics for high voltage 4H-SiC Schottky diodes with different types of metal-polymeric packages

The dV/dt and dI/dt characteristics for 4H-SiC Schottky type diodes with different type metal-polymeric packages have been studied experimentally. It is determined that experimental dV/dt values for 4H-SiC Schottky type diodes in large-sized and small-sized metal-polymeric packages type (TO-220, SOT-89, QFN, PQFN) are varying in interval of 753÷1087 V/ns. For the first for time 4H-SiC Schottky type diodes have been determined experimentally another important diode’s characteristics dI/dt which are varying in interval of 1.91÷4.00 A/ns for all diodes It is established that package’s size miniaturization not lead to characteristics degradation (dV/dt and dI/dt) during of impulse mode of operation that is positive factor for the for diode failure-free operation during of impulse mode.

On the Multi-parallel Diodes Model in Au/PVA/n-GaAs Schottky Diodes and Investigation of Conduction Mechanisms (CMs) in a Temperature Range of 80–360 K

Au/PVA/n-GaAs (MPS) type Schottky diodes (SDs) were fabricated and investigated in a temperature range of 80–360 K to explain their possible conduction mechanisms (CMs). Three distinct linear regions with different slopes were observed in ln(I)–V plots. The first region (R1), is within the range of 0.22–0.60 V, the second region (R2), is within the range of 0.64–0.90 V, and the third region (R3), is within the range of 1.1–1.5 V. It was shown that both ideality factor (n) and zero-bias barrier height (ΦBo) are strong functions of temperature for all three regions. It was noticed that n values decreased and ΦBo values increased with increasing temperature. In order to ascertain the possible CMs, ΦBo − n, − ΦBo − q/2kT, and (n−1 − 1) − q/2kT plots were also examined. In each of these plots, two linear regions were obtained within each of the three regions. The region from 80–180 K is called the low-temperature range (LTR), and the region from 200–360 K is called the high-temperature range (HTR). It has been revealed that the reason for the deviation from the classical thermionic emission (TE) theory cannot be explained only by the existence of the interface layer, interface states (NSS) or quantum mechanical tunneling mechanisms, which can be also explained by the double Gaussian distribution (DGD) due to barrier inhomogeneity. Finally, the experimental Richardson constants (A*) were calculated from the interception point of the modified Richardson curve in LTR and HTR for all three regions. It was calculated as 6.22 and 8.13 A/cm2K2 for RI, 7.77 and 8.14 A/cm2K2 at R2, and 7.07 and 8.13 A/cm2K2 at R3 for low- and high-temperature ranges, respectively. It is clear that especially HTR results are quite close to the known theoretical A* value of 8.16 A/cm2K2 for n-GaAs.

New type Schottky diodes based on the heterostructure of transition metal oxides: p-La2/3Sr1/3VO3/n-TiO2

We make a new type of bipolar Schottky diodes using the p-type La2/3Sr1/3VO3 (LSVO)/n-TiO2 heterostructure. The p-type LSVO metal thin films are grown on various substrates using radio frequency magnetron co-sputtering deposition. We find that the LSVO film grown on anatase TiO2 layer produce the lowest resistivity of 0.28 mΩ cm. We discover that the resistivity decreases with decreasing LSVO film thickness for LSVO/TiO2/Si structures. Hall measurements are performed and the dielectric functions of LSVO films are measured. The effective mass of LSVO/TiO2/Si is determined to be 2.54 ± 0.05 m0. The current-voltage curves of the Schottky diodes of p-LSVO/n-TiO2 is measured and is explained using band alignment diagram. We identify a new type of Schottky diode, where both electrons in n-TiO2 and holes in p-LSVO can flow under bias.

The Design of Terahertz Monolithic Integrated Frequency Multipliers Based on Gallium Arsenide Material.

A global design method for a terahertz monolithic integrated frequency multiplier is proposed. Compared with a traditional independent design, the method in this paper adopts overall optimization and combines the device with the circuit design. The advantage is that it provides a customized design for frequency multipliers according to specifications. On the basis of the gallium arsenide process of the Institute of Microelectronics, Chinese Academy of Sciences, two types of Schottky diodes have been developed to meet the needs of different designs. On the one hand, a Schottky diode with a 3 μm junction’s diameter was used in the design of the 200 GHz balanced doubler and, on the other hand, a diode with a 5 μm diameter was used in the 215 GHz unbalanced tripler. The measured results indicated that the output power of the doubler was more than 250 μW at 180~218 GHz, and the maximum was 950 μW at 198 GHz when driven with 12.3 mW, whereas that of the tripler was above 5 mW at 210~218 GHz and the maximum exceeded 10 mW. Such frequency multiplier sources could be widely used in terahertz imaging, radiometers, and so on.

Microstructural and interface properties of Au/SrTiO3 (STO)/n-GaN heterojunction with an e-beam evaporated high-k STO interlayer

This paper reviews the microstructural and electrical properties of Au/n-GaN metal/semiconductor (MS) diode with an e-beam evaporated SrTiO3(STO) as an insulating layer between the Au and n-GaN substrate. The microstructural properties of STO thin films are assessed by employing XRD and TEM approaches and the results reveal that the STO thin films are formed on n-GaN surface. Then, the Au/STO/n-GaN heterojunction (HJ) type Schottky diode is fabricated and measured its electrical characteristics by current-voltage (I–V) and capacitance-voltage (C–V) techniques. The HJ exhibits lower reverse leakage current compared to the MS diode. Higher barrier height is achieved for the HJ (0.86 eV) than the MS diode (0.67 eV) with ideality factors of 1.86 and 1.21. This implies that the barrier height is modified by the STO insulating layer. Using Z(V,T)i - Vd and ΨS-V plots, the barrier heights of MS diode and HJ are also evaluated and compared with one another. The derived interface state density (NSS) of HJ is lower than the MS diode, demonstrating that the STO layer plays a substantial role in the reduced NSS. Results suggest that the STO thin film is a promising high-k material for the development of new electronic device applications.

Superior photoresponse MIS Schottky barrier diodes with nanoporous:Sn–WO3 films for ultraviolet photodetector application

Nanoporous:Sn–WO3 film based metal–insulator–semiconductor type Schottky diodes exhibit ultra-high responsivity with higher quantum efficiency and detectivity.

Positive effects of a Schottky-type diode on unidirectional resistive switching devices

In this research, 1-diode (1D), 1-resistor (1R), and 1D1R stacked devices were separately fabricated using a 400 nm diameter hole substrate. It was observed that, in 1D1R, there was a fivefold increase in endurance and 52% improvement in the resistance distribution characteristics compared to those of 1R. It could be surmised that the stacked diode not only plays the role of a selection device to minimize the interference in the crossbar array type resistive switching device but also acts as an external load resistor to suppress the unexpected current overflow during resistance transition. These experimental results demonstrated that the optimized diode shows significant promise as a unidirectional resistive switching device for memory-related applications.