Schottky Interface Research Articles

Liquid Metal‐Based Perovskite Solar Cells: In Situ Formed Gallium Oxide Interlayer Improves Stability and Efficiency

AbstractIn this study, eutectic gallium–indium alloy (EGaIn) liquid metal is used as the rear electrode for perovskite solar cells (PSCs), where the interfacial properties of the device, particularly the beneficial roles of the surface oxide of the liquid metal, are explored. The findings demonstrate that the native oxide of the EGaIn electrode significantly affects the stability of photovoltaic performance and impedance characteristics including series and shunt resistances. Based on the results, the following hypothesis is formulated: the oxide interlayer serves two crucial functions of a barrier against metal diffusion and a tunnel for enhancing charge extraction and transfer. The results of elemental mapping and trap density calculation support the former function of the hypothesis that the oxide film can effectively prevent metal penetration into the perovskite layer. Furthermore, measurements involving capacitance−voltage and time‐resolved photoluminescence confirm that the oxide film on the liquid metal eliminates the interfacial Schottky barrier, promoting efficient charge extraction and transfer processes. Finally, the investigation is extended to develop flexible PSCs using the EGaIn electrode, which consistently exhibits stable performance during repeated bending cycles. Notably, the EGaIn rear electrode can be readily removed and collected through a straightforward acid treatment, offering a promising avenue for efficient cell recycling.

Ga-polar GaN Camel diode enabled by a low-cost Mg-diffusion process

In this letter, we show that low-cost physical vapor deposition of Mg followed by a thermal diffusion annealing process increases the effective barrier height at the metal/Ga-polar GaN Schottky interface. Thus, for the first time, GaN Camel diodes with improved barrier height and turn-on voltage were realized compared to regular GaN Schottky barrier diodes. Temperature-dependent current–voltage characteristics indicated a near-homogeneous and near-ideal behavior of the GaN Camel diode. The analysis performed in this work is thought to be promising for improving the performance of future GaN-based unipolar diodes.

Schottky Heterojunction Facilitates Osteosarcoma Ferroptosis and Enhances Bone Formation in a Switchable Mode

AbstractEffective antitumor agents with concurrent osteogenic properties are essential for comprehensive osteosarcoma (OS) treatment. However, the current clinical therapeutic strategies of OS fail to completely eradicate tumors while simultaneously encouraging bone formation. To address this issue, a switchable strategy for dynamic OS ablation and static bone regeneration is developed by integrating piezoelectric BaTiO3 (BTO) with atomic‐thin Ti3C2 (TC) through a Schottky heterojunction, resulting in the formation of TC@BTO. Under sequential ultrasound and near‐infrared irradiation, the optimized carrier transport of TC@BTO, based on Schottky heterojunction, exhibits excellent characteristics of photothermal conversion and reactive oxygen species generation. This results in ferroptosis of tumor cells and eventual elimination of OS. Moreover, in the static state, the interfacial Schottky heterojunction facilitates the carriers’ directed transfer from the semiconductor to the metal. The Schottky heterojunction‐enhanced static electrical stimulation enhances the osteogenic differentiation of bone marrow‐derived mesenchymal stem cells and repair of bone defects. Furthermore, RNA‐sequencing analysis reveals that static TC@BTO promotes bone regeneration by activating Wnt signaling pathway, and remarkably, pharmacological inhibition of Wnt signaling suppresses the TC@BTO‐induced osteogenesis. Overall, this work broadens the biomedical potential of Schottky heterojunction‐based therapies and provides a comprehensive strategy for overall OS ablation and bone regeneration.

Broad spectral response to photon energy unlimited by Schottky barrier from NiSi/Si junction

Recent advances in plasmonic absorption devices offer a novel approach for extending the range of silicon light detection. This is achieved by exploiting the Schottky interface energy barrier, which overcomes the limitation of the 1.12 eV photon energy conversion imposed by the silicon intrinsic bandgap. Internal photoemission has been widely accepted as the primary emission mechanism, which is mostly limited by the Schottky barrier height. However, we have discovered that carriers with energy lower than the Schottky barrier can generate electrical responses through the photothermal effect, breaking this restriction. In this study, we closely investigate two forms of photoresponses, namely photoelectric and photothermal, on a NiSi thin film Schottky photodetector, considering various factors such as temperature, applied bias, incident power, and wavelength regime. Without photothermal assistance, the device achieves a responsivity of 0.41 mA/W to a 1550 nm laser. Under bias-driven conditions, highly energized hot carriers generate a 2.18 μA photoelectric response, while a 0.861 μA photothermal response is simultaneously observed under 6 mW 1550 nm laser illumination. Through systematic investigation, we advance the mechanism of both responses by combining the hot carrier model and the Schottky barrier diagram. Finally, we experimentally obtain a 4.85 μA sheer photothermal response to a 0.475 mW 4-μm wavelength signal with 10.21 mA/W responsivity. It is expected that the device will also show responses to longer wavelengths.

NiFe LDH/MoS2/Ni3S2 p-n/Mott-Schottky heterojunction for efficient hydrogen generation coupled with electrochemical oxidation of organic molecules

Urea and organic molecules assisted electrochemical water splitting is a promising strategy to realize energy-saving hydrogen production and simultaneous treatment of wastewater containing urea and organic pollutants. It is an effective approach to develop advanced electrocatalysts being of excellent catalytic performance by constructing a metal-semiconductor or semiconductor-semiconductor heterogeneous interface to regulate the electronic structure, thus forming the highly catalytic sites. Herein, we prepared a NiFe LDH/MoS2/Ni3S2 ternary heterojunction as a bifunctional catalyst on nickel foam (NiFe LDH/MoS2/Ni3S2/NF) via constructing Schottky interface and p-n heterojunction interface. In view of the built-in electric field between the heterogeneous interfaces, the electron transfer in interfaces is accelerated, and the adsorption of OH- and the dissociation of urea are also promoted, which results in excellent electrocatalytic performance including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), urea oxidation reaction (UOR) and ethanol oxidation reaction (ETOR). At 50 mA cm−2, the voltages of HER, OER, UOR and ETOR are −0.100, 1.511, 1.410, 1.427 V vs. RHE, respectively, better than the most of reported electrocatalysts. In two-electrode electrolytic cells using NiFe LDH/MoS2/Ni3S2/NF as cathode and anode catalysts, this material also exhibits the outstanding catalytic performance in electrolytes of 1.0 M KOH, 1.0 M KOH containing 0.5 M urea and 1.0 M KOH containing 0.5 M lactic acid. This research provides a feasible approach for constructing advanced electrocatalysts by combining the different metal-based compounds to form the heterojunction with highly catalytic sites, thus realizing the aim of acquiring hydrogen energy and simultaneous treatment of urea wastewater and other organic pollutants.

In situ synthesis of bi-functional NH2-Ti2C3Tx@COF Schottky heterojunction through interfacial electron effects for enhancing U(VI) photoreduction

Reduction of soluble U(VI) to insoluble U(IV) is considered as a promising strategy to avoid uranium contamination. Herein, a bi-functional covalent organic framework based heterojunction (NH2-Ti3C2Tx@COF) was constructed on the amino-modified Ti3C2Tx MXene for efficient photoreduction U(VI) without additional sacrificial agents. Schottky interface with electronic unidirectional channel is established by the formation of local electrophilic/nucleophilic region due to the introduction of reductive COF with alkynyl group, resulting in efficient photogenerated carrier separation and solar energy utilization. More importantly, NH2-Ti3C2Tx with negative charge served as electron collector and transfer channel can effectively surmount the low photocatalytic activity caused by high polarization of imine-linked COFs. Thus, the tailored-made design of NH2-Ti3C2Tx@COF exhibits excellent photocatalytic activity, fast reaction kinetics (removal of 97.8 % in 60 min) and high adsorptive capability (1557.2 mg/g) under the light condition. This multiple-in-one advantage makes well-designed NH2-Ti3C2Tx@COF as a promising capture platform. This work will provide some new insight and inspiration to COF based heterojunctions for enhancing U(VI) capture.

Ultralow Off‐State Current and Multilevel Resistance State in Van der Waals Heterostructure Memristors

AbstractMemristors based on 2D semiconductors hold great promise due to their atomic‐level thickness and tunable optoelectronic properties. However, a significant challenge lies in suppressing the large off‐state current, which leads to additional standby power consumption. Here, a simple and versatile method is presented to address this issue by introducing a thin h‐BN interlayer between 2D semiconductors and the electrodes. The thickness of the h‐BN interlayer serves as a pivotal parameter for modulating the interfacial Schottky barrier, thereby influencing the off‐state current level. This fabricated graphene/α‐In2Se3/h‐BN/Cr‐Au memristor, forming a van der Waals heterostructure, exhibits unipolar resistive switching behavior. Remarkably, the memristor incorporating an 8 nm h‐BN interlayer showcases an ultralow off‐state current of 4.2 × 10−13 A, five orders of magnitude lower than that without the h‐BN interlayer. It also achieves a current switching on/off ratio of up to 109 and realizes 32 distinct resistance states, enabling robust multi‐bit memory capabilities. Excellent stability and durability are maintained due to the self‐encapsulation of the h‐BN interlayer. Furthermore, this method is also applicable to memristors built on HfS2, WS2, and WSe2, highlighting its broad potential for technological applications.

Interface state analysis of Schottky-gated p-AlGaN/u-GaN/AlGaN p-FET with negligible hysteresis at high temperatures

In this Letter, we demonstrate the Schottky gated p-AlGaN/u-GaN/AlGaN p-channel field-effect transistors (p-FETs) with an extremely low interface state density of 2.5 × 1011 cm−2 eV−1. Benefiting from the high-quality Schottky interface with suppressed interface states, the excellent stability with negligible hysteresis is proved, even after ten sequential dual I–V sweeps at 150 °C. Meanwhile, the trap density, confirmed by the temperature-dependent conductance method, is still below 1012 cm−2 eV−1 at high temperature. Furthermore, the fabricated p-AlGaN/u-GaN/AlGaN p-FET with a gate to drain distance of 1.8 μm shows a breakdown voltage of −128 V and an effective on-resistance of 7.2 kΩ mm, which allows the further scale down in terms of the source–drain spacing to improve the conduction current for low voltage application. The ultra-stable I–V characteristics of the fabricated Schottky-gated p-AlGaN/u-GaN/AlGaN p-FETs show great potential for next-generation integrated circuit application at high temperatures.

Dual Localized Surface Plasmon Resonance effect enhances Nb2AlC/Nb2C MXene thermally coupled photocatalytic reduction of CO2 hydrogenation activity

Nb2AlC/Nb2C MXene (NAC/NC) heterojunction photocatalysts with Schottky junctions were obtained by selective etching of the Al layer, resulting in 146.25 μmol·g−1 electrons and 15.28 μmol·g−1 holes stored in the heterojunction. The average conversion of NAC/NC thermally coupled photocatalytic reduction of CO2 under the simulated solar irradiation reached 110.15 μmol⋅g−1⋅h−1, and the CO selectivity reached over 92%, which was 1.49 and 1.74 times higher than that of pure Nb2AlC and Nb2C MXene, respectively. After light excitation, the localized surface plasmon resonance (LSPR) effect of holes distributed on the surface of Nb2C MXene crystals in the heterojunction will form high-energy thermal holes to dissociate H2 to H+ and reduce CO2 to form H2O at the same time. The high-energy electrons formed by the LSPR effect of Nb2C MXene and the conduction band electrons generated by the photoexcitation of Nb2C MXene can be migrated to Nb2AlC under the action of the interfacial Schottky junction to supplement the electrons needed for the LSPR effect of Nb2AlC, which continuously forms high-energy hot electrons to convert the adsorbed CO2 into *CO2−, b-HCO3, and HCOO. Subsequently, HCOO releases ⋅OH in a cyclic reaction to continuously reduce to form CO. The dual LSPR effect of Nb2AlC and Nb2C MXene is used to enhance the hydrogenation activity of thermally coupled photocatalytic reduction of CO2, which provides a new research idea for the application of MXene in thermally coupled photoreduction of CO2.

Construct Schottky interface containing energy-filtering effect: An efficient strategy to decouple thermopower and conductivity

Organic/inorganic thermoelectric hybrids demonstrate great potential for wearable applications. However, their scalability is hindered by an inferior power factor (S2σ). Nowadays, achieving deep optimization of S2σ necessitates a strategy to decouple the Seebeck coefficient (S) and electrical conductivity (σ). In this work, we propose a strategy to break the coupling between S and σ by constructing a Schottky interface that exhibits an energy-filtering effect. We validate the feasibility of this approach using a PANI/TiN–TiO2/carbon paper. The results demonstrate a 1.16-fold increase in σ and a 1.08-fold increase in S in PANI/TiN–TiO2/carbon paper achieved through the construction of a Schottky-type TiN/TiO2 interface. The separation of hole/electron at the TiN/TiO2 interface serves as the scattering center for ionized impurity scattering and facilitates the transport pathway for charge carriers. These factors are crucial in determining the simultaneous optimization of S and σ, respectively. Additionally, the energy-filtering effect of the TiN/TiO2 interface plays a positive role in the ionized impurity scattering mechanism by selectively filtering out low-energy carriers. This further strengthens decoupling of the thermoelectric properties. The 14.9% PANI/11.2% TiN–14.5% TiO2/59.44% carbon paper displays the highest S2σ and achieves a high ZT value of 223.6 μVm−1 K−2 and 0.31 at 300 K, highlighting the advantages of PANI-based thermoelectric hybrids. This work provides valuable guidance for the design of thermoelectric hybrids incorporating multi-interface morphology.

Defect‐Hydrogen Interactions in Top‐Anode Oxide Semiconductor Schottky Barrier Diode

AbstractAs amorphous oxide semiconductors (AOSs) are hotly pursued for advanced displays, flexible electronics, optoelectronics, and neuromorphic systems, the AOS Schottky barrier diodes (SBDs) have been tried only using the mainstream amorphous InGaZnO (a‐IGZO) and the conservative bottom‐anode structure. To deepen the study on AOS SBDs, the more challenging top‐anode SBD is developed in this work using a versatile but vulnerable AOS, amorphous InZnO (a‐IZO). Unsurprisingly, the Schottky interface defects are seriously increased by the top‐anode process and the defective a‐IZO, which cannot be effectively passivated using the incumbent oxidizing treatments. The hydrogenation is proposed to considerably suppress these annoying interface defects and thus correspondingly reduces the large leakage current, while the hydrogen doping easily deteriorates a‐IGZO SBD. The underlying mechanism of such distinction is revealed to be the tricky interactions between defect and hydrogen in AOSs. Based on the sophisticated utilization of such defect‐hydrogen interplay, the a‐IZO/a‐IGZO stack is hydrogenated together to simultaneously realize a high‐conductivity bulk and low‐defect interface, noticeably enhancing the performance metrics. Such top‐anode SBD based on hydrogenated multilayer AOSs successfully blazes a novel evolution path for AOS SBDs.

Ferroelectric Modulation in Flexible Lead-Free Perovskite Schottky Direct-Current Nanogenerator for Capsule-Like Magnetic Suspension Sensor.

The tribovoltaic nanogenerator (TVNG), a promising semiconductor energy technology, displays outstanding advantages such as low matching impedance and continuous direct-current output. However, the lack of controllable and stable performance modulation strategies is still a major bottleneck that impedes further practical applications of TVNG. Herein, by leveraging the ferroelectricity-enhanced mechanism and the control of interfacial energy band bending, a lead-free perovskite-based (3,3-difluorocyclobutylammonium)2 CuCl4 ((DF-CBA)2 CuCl4 )/Al Schottky junction TVNG is constructed. The multiaxial ferroelectricity of (DF-CBA)2 CuCl4 enables an excellent surface charge modulating capacity, realizing a high work function regulation of ≈0.7eV and over 15-fold current regulation (from 6 to 93µA) via an electrical poling control. The controllable electrical poling leads to elevated work function difference between the Al electrode and (DF-CBA)2 CuCl4 compared to traditional semiconductors and halide perovskites, which creates a stronger built-in electric field at the Schottky interface to enhance the electrical output. This TVNG device exhibits outstanding flexibility and long-term stability (>20000 cycles) that can endure extreme mechanical deformations, and can also be used in a capsule-like magnetic suspension device capable of detecting vibration and weights of different objects as well as harvesting energy from human motions and water waves.

Determination of temperature sensitivity and current-transport mechanisms of the GaAs-based MS contact

In this study, the GaAs-based metal-semiconductor (MS) contact was prepared as a reference sample for comparison with other devices in the literature, especially some interfacial layered Schottky structures and temperature sensors. The study also includes investigating and evaluating essential device parameters for determining current-transport mechanisms (CTMs) and temperature-sensing behavior. In fact, the benefits of the insulator/organic interfacial layer in devices, such as controlling charge transfers and preventing diffusion at the MS interface, have been mentioned a lot in the literature. However, since the production processes of the MS contact are easier and less costly than interfacial-layered devices, it would be more logical/suitable to prefer it in applications where this device may be sufficient, especially as a temperature sensor. Therefore, the current-voltage (I-V) data of the produced MS contact was obtained in a wide temperature range to determine the CTMs, and it was observed that two linear areas with different slopes, known as the two-parallel diode model, existed in the GaAs-based MS contact. Therefore, essential contact parameters and graphs were obtained for both two regions, and it was obtained that quantum mechanical tunneling mechanisms, the T0 effect, and the Double Gaussian Distribution (DGD) with Thermionic Emission theory play a role as CTMs of the GaAs-based MS contact such as some interfacial layered devices given in the literature. On the other hand, the temperature sensitivity of the MS contact was examined, and it was observed that the sensitivity parameter values exhibit an excellent quality sensing behavior compared to other devices in the literature, including devices with high-temperature sensitivity. Therefore, it can be preferred as a temperature sensor in many applications due to its low cost and easy production processes.

Defect Pyrochlore‐Type Mott–Schottky Photocatalysts for Enhanced Ammonia Synthesis at Low Pressure

AbstractThe ambient ammonia synthesis coupled with distributed green hydrogen production technology can provide promising solutions for low‐carbon NH3 production and H2 storage. Herein, we reported Ru‐loaded defective pyrochlore K2Ta2O6−x with remarkable visible‐light absorption and a very low work function, enabling effective visible‐light‐driven ammonia synthesis from N2 and H2 at low pressure down to 0.2 atm. The photocatalytic rate was 2.8 times higher than that of the best previously reported photocatalyst and the photo‐thermal rate at 425 K was similar to that of Ru‐loaded black TiO2 at 633 K. Compared to perovskite‐type KTaO3−x with the same composition, the pyrochlore exhibited a 3.7‐fold increase in intrinsic activity due to a higher photoexcited charge separation efficiency and a higher conduction band position. The interfacial Schottky barrier and spontaneous electron transfer between K2Ta2O6−x and Ru further improve photoexcited charge separation and accumulate energetic electrons to facilitate N2 activation.

Defect pyrochlore-type Mott-Schottky photocatalysts for enhanced ammonia synthesis at low pressure.

The ambient ammonia synthesis coupled with distributed green hydrogen production technology can provide promising solutions for low-carbon NH3 production and H2 storage. Herein, we reported Ru-loaded defective pyrochlore K2Ta2O6-x with remarkable visible-light absorption and a very low work function, enabling effective visible-light-driven ammonia synthesis from N2 and H2 at low pressure down to 0.2 atm. The photocatalytic rate was 2.8 times higher than that of the best previously reported photocatalyst and the photo-thermal rate at 425K was similar to that of Ru-loaded black TiO2 at 633K. Compared to perovskite-type KTaO3-x with the same composition, the pyrochlore exhibited a 3.7-fold increase in intrinsic activity due to a higher photoexcited charge separation efficiency and a higher conduction band position. The interfacial Schottky barrier and spontaneous electron transfer between K2Ta2O6-x and Ru further improve photoexcited charge separation and accumulate energetic electrons to facilitate N2 activation.

Interfacial characteristics, metal-semiconductor contact and optical properties of CSe and BX (X=B, As and Sb) monolayers

Two dimensional (2D) materials with large family recently drawn tremendous attention due to their versatile applications. Appreciating the smooth surface and atomic thickness of 2D materials, which can be constructed in the form of heterostructures, resulting interesting chemical and physical properties in many fields. Particularly, 2D metal-semiconductor contact (MS contact), shown great promise in nanodevices and optoelectronic devices application. In this work, we have constructed the MS contact of CSe and BX (X = P, As and Sb) monolayers and investigated the interfacial characteristics, Schottky contact and optical properties, using density functional theory. Our calculated binding energies and thermal stability confirm that CSe-BX (X = P, As and Sb) MS contact are dynamically and thermally stable. Our prediction shows that CSe-BX (X = P, As and Sb) MS contact forms n-type contact, while well preserved the properties of both monolayers. A small band gap opening in CSe having high carrier mobilities, indicated that CSe-BX (X = P, As and Sb) MS contact are good candidates for high speed nanoelectronics applications. Electrostatic potential and Bader charge analysis confirm that electrons are transfer from CSe layer to the BS monolayers and the potential drops separates charge carrier at the interface, play crucial rule in power conversion efficiency. The imaginary part shows an intense absorption peak near the visible region, hence shows appalling application in photoelectronic and optical transmissions.

Temperature-dependent Schottky diode behavior of Ni Schottky contacts to α-Ga2O3 film epitaxially grown on sapphire substrate

We fabricated Ni Schottky contacts on α-Ga2O3 epitaxial layers grown on a c-plane sapphire substrate and explored their current–voltage (I–V) characteristics dependence on temperature spanning over a wide temperature range of 100–425K. The Ni/α-Ga2O3 Schottky diode displayed excellent rectification, exhibiting a high barrier height of 1.39 eV, a low leakage current of the order 10−12 A, and a breakdown voltage of 215 V at room temperature. The reverse leakage current was confined within an order of magnitude over the entire measured temperature range, indicating the thermal stability of the diode. A large ideality factor of 1.20 attained at room temperature clearly indicates the diode behavior deviation from the ideal thermionic emission theory. The I–V characteristics revealed that the barrier height and ideality factor shows strong temperature dependence, indicating the existence of barrier inhomogeneity at the Schottky interface. An analysis of the barrier inhomogeneity using the thermionic emission with the assumption of a Gaussian barrier height distribution implies the prevailing double Gaussian barrier height distribution in the Ni/α-Ga2O3 Schottky diode with a transition at 250 K. The Richardson constant derived from the modified Richardson plot, evaluated by assuming the barrier height Gaussian distribution, was close to the theoretical Richardson constant of α-Ga2O3.

Current crowding in graphene–silicon schottky diodes

The performance of the Graphene/Si (Gr/Si) Schottky interface and its potential in future electronics strongly rely on the quality of interconnecting contacts with external circuitry. In this work, we investigate the dominating and limiting factors of Gr/Si interfaces designed for high light absorption, paying particular attention to the nature of the contact failure under high electrostatic discharge (ESD) conditions. Our findings indicate that severe current crowding at contact edges of the graphene is the dominating factor for the device breakdown. Material degradation and electrical breakdown are systematically analyzed by atomic force, Raman, scanning electron, and energy-dispersive x-ray spectroscopies. This work enlists the robustness and limitations of Gr/Si junction in photodiode architecture under high ESD conditions that can be used as general guidelines for 2D–3D electronic and optoelectronic devices.

Direct Observation of Oxygen Ion Dynamics in a WO3‐x based Second‐Order Memristor with Dendritic Integration Functions

AbstractDirect observation of oxygen dynamics in an oxide‐based second‐order memristor can provide the valid evidence to clarify the memristive mechanism, however, which is still limited for now. In this study, the migration and diffusion of oxygen ions in the region of Pt/WO3‐x Schottky interface are observed in the WO3‐x second‐order memristor by using the technique of in situ transmission electron microscopy (TEM) and the electron energy loss spectroscopy. Interestingly, the coexistence of memristive and memcapacitive switching can be implemented in this memristor. Combined with the analysis of depth‐profile X‐ray photoelectron spectroscopy (XPS), an interface‐barrier‐modulation second‐order memristive model is proposed based on the above results. Notably, temporally correlative oxygen dynamics in the memristor offers the platform to integrate signals from multiple inputs, enabling the realization of the dendritic functions of synchronous and asynchronous integration for the application of logic operations with fault‐tolerance capability and associative learning. These findings provide the experimental evidence to in‐depth understanding of oxygen dynamics and switching mechanism in second‐order memristor, which can support the optimization of memristive performance and the achievement of biorealistic synaptic functions.

Understanding the complementary resistive switching in egg albumen-based single sandwich structure with non-inert Al electrode

The concept of complementary resistive switching (CRS) has been proposed as a potential solution for mitigating the unwanted sneak path current intrinsic to large-scale crossbar memory arrays. In this study, CRS devices based on egg albumen are fabricated using non-inert Al layers as the top electrodes (TE). The Al/Albumen/indium tin oxide (ITO) single sandwich structure achieves stable and reproducible CRS behavior without requiring a forming process. The application of a compliance current leads to an evolution from CRS to bipolar resistive switching (BRS). Furthermore, the BRS analog switching feature enables the emulation of synaptic functions, like paired-pulse facilitation (PPF) and paired-pulse depression (PPD). Our systematic and in-depth analyses demonstrate that the CRS is due to the interfacial Schottky barriers originating from the Al electrode oxidation. Consequently, the resistance switching behavior in the albumen-based cells with inert Pt top electrodes can further validate this model. These findings provide significant insight into the role of non-inert electrodes and contribute to a comprehensive understanding of the CRS mechanism, which may facilitate the development of high-performance CRS biodevices.