Rectification Ratio Research Articles

Polarization- and Gate-Tunable Optoelectronic Reverse in 2D Semimetal/Semiconductor Photovoltaic Heterostructure.

Polarimetric photodetector can acquire higher resolution and more surface information of imaging targets in complex environments due to the identification of light polarization. To date, the existing technologies yet sustain the poor polarization sensitivity (<10), far from market application requirement. Here, the photovoltaic detectors with polarization- and gate-tunable optoelectronic reverse phenomenon are developed based on semimetal 1T'-MoTe2 and ambipolar WSe2 . The device exhibits gate-tunable reverse in rectifying and photovoltaic characters due to the directional inversion of energy band, yielding a wide range of current rectification ratio from 10-2 to 103 and a clear object imaging with 100 × 100 pixels. Acting as a polarimetric photodetector, the polarization ratio (PR) value can reach a steady state value of ≈30, which is compelling among the state-of-the-art 2D-based polarized detectors. The sign reversal of polarization-sensitive photocurrent by varying the light polarization angles is also observed, that can enable the PR value with a potential to cover possible numbers (1→+∞/-∞→-1). This work develops a photovoltaic detector with polarization- and gate-tunable optoelectronic reverse phenomenon, making a significant progress in polarimetric imaging and multifunction integration applications.

In Situ Rapid Fabrication of Graphene-Copper Heterojunctions Using Fiber Laser Direct Writing.

Multifunctional three-dimensional heterostructures for flexible electronics have gained significant attention due to their distinctive structural formability and superior electronic and optoelectronic properties. Nevertheless, conventional fabrication techniques have yet to be optimized for flexible substrates. In this study, a straightforward fiber laser direct writing (FLDW) process is demonstrated for the simultaneous fabrication of diodes (PN junctions) and bipolar junction transistors (BJTs) on flexible polyimide substrates, which is realized through the deposition of multifunctional p- or n-type copper oxide films (CuOx) and p- or n-type porous laser-reduced graphene oxide films (LrGO) using fiber laser ablation and deposition. The presence of both p- and n-type semiconductor films is confirmed through material characterization. The fabricated PN junctions exhibit reasonable diode rectification ratios, ranging from 20 to 220, and perform reliably under numerous operating conditions such as light-dark illumination and elevated temperatures. Furthermore, I-V curve analysis indicates that the current gain and electrical performance of printed negative-positive-negative (NPN) (or positive-negative-positive, PNP) BJTs can be tailored by adjusting the laser energy density of the FLDW process and the base gap width of the BJTs. As a proof of concept, the FLDW process is successfully employed to deposit both NPN (or PNP) BJTs composed of LrGO/CuOx heterostructures with controlled current gains. Its ease of operation, versatility, and cost-effectiveness make FLDW promising for large-scale flexible electronics fabrication.

Self-driven, stable broadband photodetector based on GaAs:CdS heterojunction with ultrahigh on/off ratio and detectivity

In this study, a CdS film was successfully coated on GaAs wafer by the facile and easy method of close-spaced sublimation and a high performance visible-UV-IR, self-driven GaAs:CdS photodetector was obtained. Morphological and elemental analysis of the CdS film was performed by SEM, XRD and EDAX, respectively. The fabricated device exhibited an excellent rectification ratio of 4.90×107 in the dark, at ± 2 Vs. Furthermore, GaAs:CdS photodetector showed a superior photoresponse at zero bias, both in visible and in the UV and IR regions, due to the built-in electrical potential. The maximum photodetector parameters of the fabricated heterojunction in visible light were R = 16.91 mA/W (150 mW, V= -2.0 V), D*=8.99×1012 (150 mW, V = 0.0 V) Jones and on/off ratio = 4.27×105 (V = 0.0 V). Furthermore, R = 0.107 A/W (365 nm), R = 0.083 A/W (395 nm), R = 0.104 A/W (850 nm) were obtained at V= -2.0 Volts, while D* values ​​ of 1.972×1013 Jones (365 nm), 1.566×1013 Jones (395 nm), and 1.972×1013 Jones (850 nm) were determined for V = 0.0 Volts. Furthermore, the on/off ratios determined for 365 nm, 395 nm and 850 nm, were 1.79×105, 1.43×105 and 1.54×105, respectively at V = 0.0 V. In addition, after about 40 days, almost no significant degradation of the GaAs:CdS photodetector performance was observed.

First-Principles Approach to Elucidating Significant Rectification Ratios in Oppositely Charged Dipeptides

First-Principles Approach to Elucidating Significant Rectification Ratios in Oppositely Charged Dipeptides

Highly responsive self-driven broadband hybrid photodetector with high detectivity and on/off ratio based on Hibiscus sabdariffa

A Hibiscus sabdariffa (HBS)/n-Si hybrid photodetector was fabricated and it was observed that the device has a high rectification ratio of 10.2 × 104 in dark and superior photoresponse at different intensities of visible light in addition to UV and IR lights. The non-linear response to light intensity in visible light was attributed to phase change effects and the presence of traps, which are the result of the hibiscus sabdariffa’ response to light. The responsivity at 850 nm reaches 1.16 A W−1 (at V = −2.0 V) and a high specific detectivity of 2.0 × 1012 Jones (for self-driven mode) with an external quantum efficiency of 411% was obtained. In addition, in self-driven mode of UV and IR lights, the highest on/off ratio and NPDR values reached ∼105 and ∼109 W−1 levels, respectively. Moreover, HBS/n-Si hybrid broad-band photodetector showed long-term stability (40 days) without encapsulation both in the dark and under the light.

High-performance blue light photodetector based on PANI/CdS heterojunction

The pursuit of innovative and enhanced p-n junction photo-diodes for application in optical, optoelectronic, and microelectronic devices has become a global research focus. These diodes' fundamental operation hinges on exploiting disparities in band gaps and electronic structures of constituent materials, thereby enabling the rectification of electrical current, permitting it to flow in a single direction. In this study, we present the design and fabrication of a high-performance blue light photodetector, which uses an n-type cadmium sulfide (CdS) thin film and a p-type polyaniline (PANI). The PANI/CdS heterojunction photodetector demonstrates exceptional performance characteristics, achieving a responsivity of approximately 32 mA/W, a detectivity of approximately 4 × 1010 Jones, and a sensitivity of 5.9 × 104 % under blue light illumination at an applied bias of 30 V. Furthermore, this photodetector exhibits a remarkable rectification ratio of 78 and an impressively short response time of 60 μs. The outstanding performance attributes, including rapid response speed and rectification behavior, are attributed to the surface passivation of the CdS material and PANI chain and CdS linkage mediated states, which effectively reduces the dark current. This process enhances the efficient and rapid transport of photo-generated carriers, whereas, the interfacial nature concurrently reducing photocurrent during reverse bias conditions, thus facilitating the observed rectification effect. This research presents a significant advancement in the area of high-performance photodetectors, holding promise for a multitude of applications across optical, optoelectronic, and microelectronic devices.

An Ultrahigh‐Rectification‐Ratio WSe2 Homojunction Defined by High‐Efficiency Charge Trapping Effect

AbstractAlthough 2D material van der Waals heterostructures (vdWHs) exhibit many novel properties and applications, 2D homojunctions have unique advantages in interface lattice matching, band continuity, and charge transfer efficiency. However, the rectification performances of 2D homojunction diodes are severely limited by the small junction barrier, mainly due to inefficient charge doping. In this work, an ultrahigh‐rectification‐ratio WSe2 homojunction diode achieved by the semi‐floating gate doping of graphdiyne oxide (GDYO) is reported. Utilizing the WSe2/GDYO direct charge trapping mode can free the inhibition of charge capturing efficiency by removing conventional insulating barriers and thus improve the rectification ratio. The C─C(sp) and oxygen‐containing functional groups in the GDYO layer can provide outstanding charge‐trapping ability due to their unsaturation. Furthermore, the oxygen plasma treatment used for oxidizing graphdiyne (GDY) into GDYO can make GDYO a flatter surface, thus creating strong‐coupling WSe2/GDYO interfaces to improve the charge transfer efficiency and enhance the electrostatic doping effect. Besides, the WSe2/GDYO interfaces are confirmed to possess a higher junction barrier than that of the WSe2/GDY interfaces. This research proposes a brand‐new approach to building p–n junctions via charge trapping and the homojunction diode with a record‐highest rectification ratio of up to 106 is obtained.

Side‐Gate BN‐MoS2 Transistor for Reconfigurable Multifunctional Electronics

AbstractDeveloping 2D reconfigurable multifunctional devices is of great potential in further miniaturizing the chip area and simplifying circuit design. 2D van der Waals (vdW) heterostructures offer a novel approach to realizing reconfigurable multifunctional devices. Despite the numerous previous reports that have integrated various functions in a single 2D heterostructures device, most of those devices are based on a complex multilayer heterostructure or an air‐unstable channel material, limiting their ability to be applied in integrated circuits. There is an urgent need to develop 2D reconfigurable multifunctional devices that have a simple structure and stable electrical properties. In this work, a side‐gate reconfigurable device is illustrated based on simple BN‐MoS2 vdW heterostructures. Three different functions in a single device have been achieved, including a diode, double‐side‐gate reconfigurable logic transistor, and top floating gate memory. A lateral n+‐n homojunction is created along the MoS2 channel and the rectification ratio is above 105. Reconfigurable logic operations (OR, AND) can be achieved in a single double‐side‐gate device and the current on/off ratio is ≈t 104. Moreover, the device can act as a floating gate memory under back gate operation. Those results pave the way for integrating the same reconfigurable multifunctional devices to realize complex electronic systems.

MXene‐enhanced environmentally stable organohydrogel ionic diode toward harvesting ultralow‐frequency mechanical energy and moisture energy

AbstractWith the accelerating advancement of distributed sensors and portable electronic devices in the era of big data, harvesting energy from the surrounding environment to power electrical devices has become increasingly attractive. However, most mechanical energy harvesters often require high operating frequencies to function properly. Moreover, for practical applications, the survivability of devices in harsh operating environments is a vital issue which must be addressed. Besides, the single‐stimulus responsiveness limits their further applications in complex external environments. Here, a pressure and moisture dual‐responsive ionic diode consisting of two organohydrogels with opposite charges as an energy harvester is proposed. The organohydrogel ionic diode utilizes the migration of cations and anions to form the depletion zone and followed by an enhancement of the built‐in potential along the depletion zone as a result of mechanical stress or humidity, converting ultralow‐frequency mechanical energy or moisture energy into electrical energy. Meanwhile, this mechanism is further confirmed by the finite element analysis. With the increased rectification ratio due to the introduction of MXene, the ionic diode exhibits a relatively large output current (∼10.10 μA cm−2) and power density (∼0.10 μW cm−2) at a mechanical pressure of 0.01 Hz, outperforming most currently available mechanical energy harvesters. More impressively, the incorporation of ethylene glycol provides the hydrogel ionic diode with excellent temperature tolerance and long‐term environmental stability. The organohydrogel ionic diode can also be applied as a moisture‐driven power generator and self‐powered humidity sensor. This study presents promising prospects for the efficient collection of renewable and sustainable energy and the practical application of hydrogel‐based energy harvesters in extreme environments.

Improved resistive switching performance of amorphous InGaZnO-based memristor with the TiO2 insertion layer

A stable I–V repeatability memristor based on amorphous InGaZnO (a-IGZO) with a TiO2 insertion layer was investigated. Two memristive structures composed of Pt/a-IGZO/Pt and Pt/TiO2/a-IGZO/Pt were manufactured on SiO2/Si substrate by the magnetron sputtering method. The crystallization of IGZO thin films was analyzed by the XRD process under different annealing temperatures, and the results show that the thin films remain in a stable amorphous state. The resistive switching performance of the two structures was tested by the semiconductor parameter analyzer 4200-SCS at room temperature. After 30 cyclic scans, the Pt/a-IGZO/Pt structure shows signs of degeneration in its I–V cyclic characteristics. However, in the Pt/TiO2/a-IGZO/Pt structure, the cyclic characteristics of I–V are highly stable (cycles >105 sweeps) with a limiting operating current of 0.01 A. Its rectification ratio is approximately 20 at low operating voltages (±1.0 V), and conductance increases (or decreases) progressively with continuous positive (or negative) voltage scans. Further analysis of the experimental energy band diagram was measured by UV–vis spectra and ultraviolet photoemission spectroscopy (UPS). The results demonstrate that the operational mechanism is the modulation of the barrier at the TiO2/a-IGZO interface, which is conducive to the stable I–V cyclic characteristic of Pt/TiO2/a-IGZO/Pt memristor.

Gate voltage-controlled spin-rectifier diode based on Janus transition metal nitride MXene with spin gapless semiconductor

With the continuous application of spintronics technology, spintronic devices have been expected to become a major direction in the development of next-generation electronic devices. However, for spin rectifier diodes, how to provide a large number of spin-polarized carriers is still a key technical issue. Conventional spin-polarization injection models use ferromagnetic (FM)/semiconductor structures, but because of the conductivity mismatch can limit the injection of their polarization. This makes the search for spin-gapless semiconductor which has the conductivity between metals and semiconductors an effective way to solve this problem. Recently, MXene, a new two-dimensional material with high spin polarization, has been expected to undergo modulation of the electronic structure through external field or proximity effects. Subsequently, we propose a Janus transition metal structure of the MXene which modulates the spin properties by breaking the symmetry of the transition metals. Moreover, we find the band structure of TiCrNO2 can be effectively modulated by an applied electric field, which transforms itself from a magnetic semiconductor to a spin-gapless semiconductor under an electric field strength of 1 V/Å. With this as a basis, we construct a tunable spin rectifier diode and study its spin rectification effect by the first-principle calculations combined with non-equilibrium Green's function. The results show that the rectification ratio of the spin rectification diode can be adjustable by varying the strength of the external electric field, and its rectification rate exceeds the highest value currently available for two-dimensional rectifier devices. Our results provide a reference value for the application of nitride MXene in spintronic devices.

Non‐Volatile Reconfigurable p–n Junction Utilizing In‐Plane Ferroelectricity in 2D WSe2/α‐In2Se3 Asymmetric Heterostructures

AbstractIt is impossible to imagine modern electronic circuitry without a p–n junction—an essential building block for transistors, rectifiers, amplifiers, photovoltaics, etc. Conventional fabrication processes (ion implantation or chemical diffusion) result in an immutable potential configuration depriving reconfigurability. In contrast, the superior electrostatic tunability, dangling bonds‐ and reconstruction‐free interfaces are some of the key features of 2D based heterostructures, making them promising candidates for cutting‐edge optoelectronic and memory applications. Herein, the intercoupled 2D ferroelectricity of 𝛼‐In2Se3 is utilized to introduce micron‐scale, non‐volatile electrostatic doping in ambipolar WSe2, enabling reconfigurable p–n junction. The actuation mechanism is based on the strong polarization field along the edge topology of In2Se3. The fabricated device presents stable p–n to n–p switching, a superior rectification ratio of ≈106, and a low leakage current of ≈10−12 A. Furthermore, the switchable short‐circuit current response is utilized to demonstrate a novel self‐powered, non‐volatile memory based on photovoltaic reading. The ferroelectric non‐volatility coupled with the ability to control the device operation using optical and electrical signals paves the way for ultrathin energy‐efficient, multi‐level optoelectronic and in‐memory logic devices.

Self-Powered Photodetector Based on Ag/CH3NH3PbI3/C Asymmetric Dual-Terminal Device.

CH3NH3PbI3 is capable of exhibiting a superior photoresponse to visible light, but its self-powered devices are typically formed through p-n junctions. In this study, we fabricated a Ag/CH3NH3PbI3/C dual-terminal asymmetric electrode device using a single CH3NH3PbI3 perovskite micro/nanowire, enabling both the photoresponse and self-powered characteristics of CH3NH3PbI3 to visible light. Compared with traditional p-n junction devices, this simple device demonstrates enhanced interface photovoltaic effects by optimizing the combination of the Ag electrode with CH3NH3PbI3, resulting in superior self-powered characteristics. Under low bias voltage, the device achieves a significant on/off ratio of 103, with superior sensitivity and responsivity as well as a maximum rectification ratio of about 12. The photogenerated voltage and current reach approximately 0.8 V and 2 nA, respectively. This simple, compact, and self-powered asymmetric device exhibits great potential for applications in self-powered optoelectronics and wearable devices. This research provides a promising approach for recognizing and utilizing surface state effects in single nanoscale structures.

High-temperature optoelectronic transport behavior of n-MoS2 nanosheets/p-diamond heterojunction

In the past decades, even though the performance of electronic devices based on MoS2 has reached a very high level, the service life, failure rate and stability of the devices often deteriorate with the increase of temperature when they work in high temperature or harsh environment. In this work, n-MoS2 NSs/p-type boron-doped diamond (BDD) film heterojunction was fabricated by sol–gel method to investigate the temperature dependence of the optoelectronic transport behavior of the device, and the electrical properties of the heterojunction device at high temperature (RT-180 °C) were tested. The heterojunction presented all rectification characteristics from room temperature to 180 °C and exhibited good thermal stability. With the increase in temperature, the rectification ratio reached the maximum at 120 °C and turned into backward diodes at 160 °C and 180 °C. The mechanism of the current and rectification ratio of n-MoS2 NSs/p-BDD heterojunction changing with temperature was mainly attributed to the decrease of tunneling current caused by the shift of Fermi level of the two semiconductors at high temperature. The heterojunction undergoes a transition from tunneling current to thermal excitation current, and the shift of Fermi level to the valence band of n-MoS2 provides support for the transition to reverse diode. In accordance with the carrier transport behavior following ohmic laws, the current conduction of composite tunneling and the space charge limitation under different bias voltages and temperatures were also discussed, which provides theoretical and experimental basis for optimizing the design of new photoelectric devices in the field of high temperature optoelectronics.

High Performance Self‐Driven Photodetectors Based on MoS2 Schottky Barrier Diode

AbstractPractical application of two‐dimensional transition metal dichalcogenides (2D TMDCs) involves creating a p‐n diode and a Schottky diode. Unlike p‐n diodes, the research of 2D material‐based Schottky diodes especially in the application field of photodetectors is lacking. Here, a Schottky diode is fabricated by depositing Pt and Ni on the MoS2 to form Schottky and ohmic contacts, respectively. The MoS2 Schottky diode exhibits a rectification ratio of 2.36 × 103 and an ideality factor of 1.12. The electrical characteristics of Ni‐MoS2‐Ni and Pt‐MoS2‐Pt field effect transistors are systematically compared. The Schottky barrier height is estimated to be 94.2 meV by using the thermionic emission theory. The Schottky diode device can exhibit excellent self‐powered photodetection performance in the visible to near‐infrared region (447‐940 nm) due to the strong built‐in electric field originating from the Schottky barrier at the MoS2/Pt interface. The maximum detectivity reaches 2.09 × 1012 Jones with a response time of 52.6 ms under 940 nm laser illumination. Furthermore, the photodetection performance of such a Schottky diode can be further improved by NH3 plasma doping treatment. This work provides not only a simple approach to construct a 2D materials‐based Schottky diode photodetector but also a post treatment technique to further improve the device performance.

A Guide for Cross‐Linking Modulation: The Record Rectifying Ratio of Hydrogel‐Based Ultra Flexible Ionic Diodes

AbstractThis study focuses on the effect of cross‐linking mechanisms in the development of hydrogel‐based flexible ionic diodes (HBIDs) with desirable features for ionic devices. The research explores one p‐type hydrogel and a series of n‐type hydrogels with varying cross‐linking ratios, investigating their ion‐conducting properties, morphological and electronic structures, as well as the performance of flexible HBIDs constructed using these hydrogels. The results indicate that the cross‐linking ratio significantly influences ionic conductivity, bulk resistance, and capacitance. Additionally, the HBIDs' ability to maintain their electrical performance under repeated mechanical bending is studied concerning the cross‐linking ratio. Notably, the HBID with the highest cross‐linking ratio (HG/12) exhibits relatively higher current densities (up to 8.9 mA cm−2) and considerably higher rectification ratios (up to 1269). Even after 500 cycles of deformation, the HG/12 diode maintained a rectification ratio of 987, demonstrating its excellent performance and durability.

Van der Waals heterostructure of Bi2O2Se/MoTe2 for high-performance multifunctional devices

Two-dimensional van der Waals heterostructures exhibit distinctive electronic and optoelectronic properties, making them promising structures for constructing advanced multifunctional devices. However, devices based on conventional charge-carrier transport mechanisms often perform only a single function, which limits its integration and performance. Here, we present a vertical van der Waals heterostructure made of Bi2O2Se and MoTe2, allowing it to act as high-performance backward diode, forward diode, photodetector and photovoltaic device at various working conditions. The applications are enabled by band-alignment switching between p–n heterostructure controlled by minority carrier diffusion and n–n heterostructure governed by the thermionic emission and tunneling-mediated processes. As a backward diode, the device displays a high reverse rectification ratio of 5.0 × 104. As a photodetector, the device demonstrates a broad spectral photoresponse ranging from ultraviolet (365 nm) to near-infrared (1050 nm). When irradiated by 532 nm laser, the photodetector shows a responsivity of up to 11.6 A/W and achieves quick response/recovery speed of 19.6/8.8 μs. As a photovoltaics device, an external quantum efficiency of 78% and a responsivity of 0.33 A/W are observed. This study showcases the potential for high-performance multifunctional devices utilizing Bi2O2Se/MoTe2 heterostructures and provides comprehensive insights into the designed band alignment and its applications.

Pseudo‐Vertical Schottky Diode with Ruthenium Contacts on (113) Boron‐Doped Homoepitaxial Diamond Layers

Electrical properties of pseudo‐vertical Schottky barrier diodes (pVSBDs) prepared on (113)–oriented boron‐doped diamond (BDD) layers using ruthenium (Ru) for both the ohmic and Schottky contacts are investigated. First, Ru ohmic contacts are evaporated on homoepitaxial BDD layers with different resistivity, and their specific contact resistance is measured using circular transfer length method structures after annealing at various temperatures up to 750 °C. Then, pVSBD structures are fabricated on the boron‐doped bilayer consisting of a lower, heavily boron‐doped layer ensuring an ohmic contact and an upper, lightly doped layer providing a rectifying Schottky contact. After necessary mesa etching, both contacts are formed by the Ru evaporation. The results show that Ru forms a stable ohmic contact with very low contact resistance (10−5–10−6 Ω cm2) when deposited on BDD layers with metallic conductivity. It also provides an acceptable Schottky contact on low‐doped (113) homoepitaxial BDD. Both contacts, which are made simultaneously, realize pVSBDs with low on‐state resistance and low forward voltage drop. However, the lower barrier of the ruthenium contacts results in higher leakage. Ru pVSBDs thus show a lower rectification ratio, higher leakage, and a worse ideality factor compared to analogical pVSBDs using molybdenum contacts.

Lysine based dipeptides-molecular rectifiers with very high rectification ratio and their application towards designing logic gates

In this research paper, we have enquired the dipeptides (i.e., smallest peptides) consisting of oppositely charged amino acids namely, Lysine-Aspartic and Lysine-Glutamic, where l-Lysine is positively charged, and both L-Aspartic and L-Glutamic are negatively charged amino acids. The l-Glutamic acid has only one extra CH2 chain as compared with l-Aspartic acid. These two dipeptides are stringed to Au, Ag and Cu electrodes, to form molecular devices. Distinct parameters including conductance, Homo-Lumo gap, dipole moment, current-voltage characteristics are intrigued using NEGF-DFT technique. Au-Lysine-Aspartic-Au offers the negative differential resistance regime with the highest peak-to-valley current ratio of 28.79. Lysine-Aspartic with Cu electrodes and Lysine-Glutamic with Au electrodes offers the highest rectification ratio of 146.96 and 34.31 respectively, as compared with other electrodes. Lysine-Aspartic based dipeptides offer higher rectification ratio as compared with Lysine-Glutamic based dipeptides. Moreover, these two dipeptides offer opposite correlation between dipole moment, coupling strength and switching regimes. The reason behind rectification ratio and negative differential resistance is elaborated using transmission spectra, molecular projected self-Hamiltonian states and transmission pathway. The OR, AND and XOR logic gates are proposed using switching regimes of Au-Lysine-Aspartic-Au. We have also detected the thermal stability of one of the heterostructure using ab initio molecular dynamics simulation.

Porphyrin-Regulated Heterostructured Hydrogel Ionic Diode with a High Rectification Ratio and Output Voltage.

Nanochannel ionic diodes require extremely complex and expensive fabrication processes. Polyelectrolyte ionic diodes attracted widespread attention among ionic rectification systems due to their simplicity of development and the ability to break the size limits of the nanochannel. However, enhancement of their rectification ratio is still in the exploratory stage. In this study, chitosan (CS) hydrogels and sodium polyacrylate (PAAs) hydrogels were prepared as the substrates for the heterostructured ionic diodes. 5,10,15,20-Tetrakis(4-aminophenyl)-21H,23H-porphyrin (TAPP) was selected to regulate the rectification ratio of ionic diodes. By adding 0.05 wt % TAPP to the CS hydrogel, the rectification ratio of the ionic diode can be increased to 10, which is 4 times larger than that of the undoped ionic diode. In contrast, the rectification ratio of the ionic diodes with TAPP added in the PAAs hydrogel decreases to 2. In addition, the ionic diode composed of the TAPP-doped CS hydrogel and PAAs hydrogel has the characteristics of a high open-circuit voltage. The open-circuit voltage of the 10 mm × 10 mm × 4 mm heterojunction hydrogel reached 370 mV. The ionic diodes can be used as a self-powered power supply device.