Photo-patternable ion gel-gated graphene transistors and inverters on plastic

Combination of Polymer Gate Dielectric and Two-Dimensional Semiconductor for Emerging Field-Effect Transistors

Two-dimensional (2D) materials are considered attractive semiconducting layers for emerging field-effect transistors owing to their unique electronic and optoelectronic properties. Polymers have been utilized in combination with 2D semiconductors as gate dielectric layers in field-effect transistors (FETs). Despite their distinctive advantages, the applicability of polymer gate dielectric materials for 2D semiconductor FETs has rarely been discussed in a comprehensive manner. Therefore, this paper reviews recent progress relating to 2D semiconductor FETs based on a wide range of polymeric gate dielectric materials, including (1) solution-based polymer dielectrics, (2) vacuum-deposited polymer dielectrics, (3) ferroelectric polymers, and (4) ion gels. Exploiting appropriate materials and corresponding processes, polymer gate dielectrics have enhanced the performance of 2D semiconductor FETs and enabled the development of versatile device structures in energy-efficient ways. Furthermore, FET-based functional electronic devices, such as flash memory devices, photodetectors, ferroelectric memory devices, and flexible electronics, are highlighted in this review. This paper also outlines challenges and opportunities in order to help develop high-performance FETs based on 2D semiconductors and polymer gate dielectrics and realize their practical applications.

High performance enhancement-mode thin-film transistor with graphene quantum dot-decorated In2O3 channel layers

Due to the quantum confinement and edge effects, there has been ongoing enthusiasm to provide deep insight into graphene quantum dots (GQDs), serving as attractive semiconductor materials. To demonstrate the potential applications of GQDs in electronic devices, this work presents solution-processed high performance GQD-decorated In₂O₃ thin-film transistors (TFTs) based on ZrO₂ as gate dielectrics. GQDs-In₂O₃/ZrO₂ TFTs with optimized doping content have demonstrated high electrical performance and low operating voltage, including a larger field-effect mobility (μ_FE) of 34.02 cm² V⁻¹ s⁻¹, a higher I_on/I_off of 4.55 × 10⁷, a smaller subthreshold swing (SS) of 0.08 V dec⁻¹, a lower interfacial trap states (D_it) of 5.84 × 10¹¹ cm⁻² and threshold voltage shift of 0.07 V and 0.12 V under positive bias stress (PBS) and negative bias stress (NBS) for 3600 s, respectively. As a demonstration of complex logic applications, a resistor-loaded unipolar inverter based on GQDs-In₂O₃/ZrO₂ has been built, demonstrating full swing characteristic and high gain of 10.63. Low-frequency noise (LFN) characteristics of GQDs-In₂O₃/ZrO₂ TFTs have been presented and it was concluded that the noise source can be attributed to the fluctuations in mobility. As a result, it can be concluded that solution-derived GDQ-optimized oxide-based TFTs will manifest potential applications in electronic devices.

Due to the quantum confinement and edge effects, there has been ongoing enthusiasm to provide deep insight into graphene quantum dots (GQDs), serving as attractive semiconductor materials.

Low Voltage Graphene-Based Amplitude Modulator for High Efficiency Terahertz Modulation

In this paper, a high-efficiency terahertz amplitude modulation device based on a field-effect transistor has been proposed. The polarization insensitive modulator is designed to achieve a maximum experimental modulation depth of about 53% within 5 V of gate voltages using monolayer graphene. Moreover, the manufacturing processes are inexpensive. Two methods are adopted to improve modulation performance. For one thing, the metal metamaterial designed can effectively enhance the electromagnetic field near single-layer graphene and therefore greatly promote the graphene’s modulation ability in terahertz. For another, polyethylene oxide-based electrolytes (PEO:LiClO₄) acts as a high-capacity donor, which makes it possible to dope single-layer graphene at a relatively low voltage.

Numerical and Theoretical Study of Tunable Plasmonically Induced Transparency Effect Based on Bright-Dark Mode Coupling in Graphene Metasurface

In this paper, we numerically and theoretically study the tunable plasmonically induced transparency (PIT) effect based on the graphene metasurface structure consisting of a graphene cut wire (CW) resonator and double split-ring resonators (SRRs) in the middle infrared region (MIR). Both the theoretical calculations according to the coupled harmonic oscillator model and simulation results indicate that the realization of the PIT effect significantly depends on the coupling distance and the coupling strength between the CW resonator and SRRs. In addition, the geometrical parameters of the CW resonator and the number of the graphene layers can alter the optical response of the graphene structure. Particularly, compared with the metal-based metamaterial, the PIT effect realized in the proposed metasurface can be flexibly modulated without adding other actively controlled materials and reconstructing the structure by taking advantage of the tunable complex surface conductivity of the graphene. These results could find significant applications in ultrafast variable optical attenuators, sensors and slow light devices.

Low-Power Complementary Logic Circuit Using Polymer-Electrolyte-Gated Graphene Switching Devices

The modulation of the electrical properties of graphene and its device configurations for low-power consumption are important in developing graphene-based logic electronics. Here, we demonstrate the change in the charge transport in graphene from ambipolar to unipolar using surface charge transfer doping of the polymer electrolyte. Unipolar graphene field-effect transistors (GFETs) were obtained by the surface treatment of poly(acrylic acid) (PAA) for p-type and poly(ethyleneimine) (PEI) for n-type as polymer-electrolyte gates. In addition, lithium perchlorate (LiClO₄) in a polymer matrix can be used for the low-gate voltage operation of GFETs (less than ±3 V) because of its high gating efficiency. Using polymer-electrolyte-gated GFETs, complementary graphene inverters were fabricated with a voltage swing of 57% and maximum voltage gain (V_gain) of 1.1 at a low supply voltage (V_DD = 1 V). This is expected to facilitate the development of graphene-based logic devices with low-cost, low-power, and flexible electronics.

Highly Flexible and Stable Solid-State Supercapacitors Based on a Homogeneous Thin Ion Gel Polymer Electrolyte Using a Poly(dimethylsiloxane) Stamp

To achieve both high structural integrity and excellent ion transport, designing ion gel polymer electrolytes (IGPEs) composed of an ionic conducting phase and a mechanical supporting polymer matrix is one of the promising material strategies for the development of next-generation all-solid-state energy storage systems. Herein, we prepared an IGPE thin film, in which an ion-diffusing phase containing ionic liquids and lithium salts was bicontinuously intertwined with a cross-linked epoxy phase, using a silicon elastomer-based stamping method, thus producing a homogeneous IGPE-based thin film with low surface roughness (R_rms = 0.5 nm). Following the optimization of the IGPE thin film in terms of the concentrations of ionic constituents, the film thickness, and various process parameters, the IGPE itself showed a high ionic conductivity of 0.23 mS/cm with a low activation energy for lithium-ion transport, as well as the high capacitance of approximately 10 μF/cm² based on the metal-insulator-metal configuration. Furthermore, an all-solid-state supercapacitor containing two IGPE coating-activated carbon electrodes produced using our poly(dimethylsiloxane) (PDMS) stamping method exhibited high energy and power densities (44 W h/kg at 875 W/kg and 28 kW/kg at 3 W h/kg). It was also found that this supercapacitor showed a dramatic reduction (more than 50%) of the current-resistance (IR) drop, which is an indicator of low interface resistance, while maintaining the initial electrochemical performance even after severe mechanical deformation such as bending or rolling. Therefore, all these results support the fact that our developed PDMS stamping method enables the rendering of a high-performance ion gel polymer thin-film-based electrolyte with acceptable stability and mechanical flexibility for all-solid-state wearable energy storage devices.

Remote Gating of Schottky Barrier for Transistors and Their Vertical Integration

This paper introduces a strategy to modulate a Schottky barrier formed at a graphene-semiconductor heterojunction. The modulation is performed by controlling the work function of graphene from a gate that is placed laterally away from the graphene-semiconductor junction, which we refer to as the remote gating of a Schottky barrier. The remote gating relies on the sensitive work function of graphene, whose local variation induced by locally applied field effect affects the change in the work function of the entire material. Using Kelvin probe force microscopy analysis, we directly visualize how this local variation in the work function propagates through graphene. These properties of graphene are exploited to assemble remote-gated vertical Schottky barrier transistors (v-SBTs) in an unconventional device architecture. Furthermore, a vertical complementary circuit is fabricated by simply stacking two remote-gated v-SBTs (pentacene layer as the p-channel and indium gallium zinc oxide layer as the n-channel) vertically. We consider that the remote gating of graphene and the associated device architecture presented herein facilitate the extendibility of graphene-based v-SBTs in the vertical assembly of logic circuits.

Morphological/nanostructural control toward intrinsically stretchable organic electronics

The development of intrinsically stretchable electronics poses great challenges in synthesizing elastomeric conductors, semiconductors and dielectric materials.

Paper-Based Supercapacitive Mechanical Sensors

Paper has been pursued as an interesting substrate material for sensors in applications such as microfluidics, bio-sensing of analytes and printed microelectronics. It offers advantages of being inexpensive, lightweight, environmentally friendly and easy to use. However, currently available paper-based mechanical sensors suffer from inadequate range and accuracy. Here, using the principle of supercapacitive sensing, we fabricate force sensors from paper with ultra-high sensitivity and unprecedented configurability. The high sensitivity comes from the sensitive dependence of a supercapacitor's response on the contact area between a deformable electrolyte and a pair of electrodes. As a key component, we develop highly deformable electrolytes by coating ionic gel on paper substrates which can be cut and shaped into complex three-dimensional geometries. Paper dissolves in the ionic gel after determining the shape of the electrolytes, leaving behind transparent electrolytes with micro-structured fissures responsible for their high deformability. Exploiting this simple paper-based fabrication process, we construct diverse sensors of different configurations that can measure not just force but also its normal and shear components. The new sensors have range and sensitivity several orders of magnitude higher than traditional MEMS capacitive sensors, in spite of their being easily fabricated from paper with no cleanroom facilities.

Potential solution-induced HfAlO dielectrics and their applications in low-voltage-operating transistors and high-gain inverters

Recently, much attention has been paid to the investigation of solution-driven oxides for application in thin film transistors (TFTs). In current study, a fully solution-based method, using 2-methoxyethanol as solvent, has been adopted to prepare InZnO thin films and HfAlO _x gate dielectrics. Amorphous HfAlO _x thin films annealed at 600 °C have shown a high transparency (>85%), low leakage current density (6.9 × 10^-9 A cm^-2 at 2 MV cm^-1), and smooth surface. To verify the potential applications of HfAlO _x gate dielectrics in oxide-based TFTs, fully solution-induced InZnO/HfAlO _x TFTs have been integrated. Excellent electrical performance for InZnO/HfAlO _x TFTs annealed at 450 °C has been observed, including a low operating voltage of 3 V, a saturated mobility of 5.17 cm² V^-1 s^-1, a high I _on/I _off of ∼10⁶, a small subthreshold swing of 87 mV per decade, and a threshold voltage shift of 0.52 V under positive bias stress (PBS) for 7200 s, respectively. In addition, time dependent threshold voltage shift under PBS could be described by a stretched-exponential model, which can be due to charge trapping in the semiconductor/dielectric interface. Finally, to explore the possible application in logic operation, a resistor-loaded inverter based on InZnO/HfAlO _x TFTs has been built and excellent swing characteristic and well dynamic behavior have been obtained. Therefore, it can be concluded that fully solution-driven InZnO/HfAlO _x TFTs have demonstrated potential application in nontoxic, eco-friendly and low-power consumption oxide-based flexible electronics.

Metal-agglomeration-suppressed growth of MoS2 and MoSe2 films with small sulfur and selenium molecules for high mobility field effect transistor applications

This work reports a breakthrough technique for achieving high quality and uniform molybdenum dichalcogenide (MoX2 where X = S, Se) films on large-area wafers via metal-agglomeration-suppressed growth (MASG) with small chalcogen (X-) molecules at growth temperatures (TG) of 600 °C or lower. In order to grow MoS2 films suitable for field effect transistors (FETs), S-molecules should be pre-deposited on Mo films at 60 °C prior to heating the substrate up to TG. The pre-deposited S-molecules successfully suppressed the agglomeration of Mo during sulfurization and prevented the formation of protruding islands in the resultant sulfide films. The small X-molecules supplied from a thermal cracker reacted with Mo-precursor film to form MoX2. The film quality strongly depends on the temperatures of cracking and reservoir zones, as well as TG. The MoS2 film grown at 570 °C showed a thickness variation of less than 3.3% on a 6 inch-wafer. The mobility and on/off current ratio of 6.1 nm-MoS2 FET at TG = 570 °C were 59.8 cm2 V-1 s-1 and 105, respectively. The most significant advantages of the MASG method proposed in this work are its expandability to various metal dichalcogenides on larger substrates as well as a lower TG enabled by using reactive small molecules supplied from a cracker, for which temperature is independently controlled.

Ambient Processed, Water-Stable, Aqueous-Gated sub 1 V n-type Carbon Nanotube Field Effect Transistor

In this paper we report for the first time an n-type carbon nanotube field effect transistor which is air- and water-stable, a necessary requirement for electrolyte gated CMOS circuit operation. The device is obtained through a simple process, where the native p-type transistor is converted to an n-type. This conversion is achieved by applying a tailor composed lipophilic membrane containing ion exchanger on the active channel area of the transistor. To demonstrate the use of this transistor in sensing applications, a pH sensor is fabricated. An electrolyte gated CMOS inverter using the herein proposed novel n-type transistor and a classical p-type transistor is demonstrated.

Highly Conductive, Photolithographically Patternable Ionogels for Flexible and Stretchable Electrochemical Devices

An ionic conducting membrane is an essential part in various electrochemical devices including ionic actuators. To miniaturize these devices, micropatterns of ionic conducting membrane are desired. Here, we present a novel type of ionogel that can be patterned using standard photolithography and soft imprinting lithography. The ionogel is prepared in situ by UV-initiated free-radical polymerization of thiol acrylate precursors in the presence of ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. The resultant ionogel is very flexible with a low Young's modulus (as low as 0.23 MPa) and shows a very high ionic conductivity (up to 2.4 × 10^-3 S/cm with 75 wt % ionic liquid incorporated) and has a reactive surface due to the excess thiol groups. Micropatterns of ionogel are obtained by using the thiol acrylate ionogel solution as an ionic conducting photoresist with standard photolithography. Water, a solvent immiscible with ionic liquid, is used as the photoresist developer to avoid complete removal of ionic liquid from thin micropatterns of the ionogel. By taking advantage of the reactive surface of ionogels and the photopatternability, ionogels with complex three-dimensional microstructure are developed. The surface of the ionogels can also be easily patterned using UV-assisted soft imprinting lithography. This new type of ionogels may open up for building high-performance flexible electrochemical microdevices.

A Hybrid Gate Dielectrics of Ion Gel with Ultra-Thin Passivation Layer for High-Performance Transistors Based on Two-Dimensional Semiconductor Channels

We propose a hybrid gate structure for ion gel dielectrics using an ultra-thin Al₂O₃ passivation layer for realizing high-performance devices based on electric-double-layer capacitors. Electric-double-layer transistors can be applied to practical devices with flexibility and transparency as well as research on the fundamental physical properties of channel materials; however, they suffer from inherent unwanted leakage currents between electrodes, especially for channel materials with low off-currents. Therefore, the Al₂O₃ passivation layer was introduced between the metal electrodes and ion gel film as a leakage current barrier; this simple approach effectively reduced the leakage current without capacitance degradation. In addition, we confirmed that a monolayer MoS₂ transistor fabricated with the proposed hybrid gate dielectric exhibited remarkably enhanced device properties compared to a transistor using a normal ion gel gate dielectric. Our findings on a simple method to improve the leakage current properties of ion gels could be applied extensively to realize high-performance electric-double-layer transistors utilizing various channel materials.

Rivet Graphene

Large-area graphene has emerged as a promising material for use in flexible and transparent electronics due to its flexibility and optical and electronic properties. The anchoring of transition metal nanoparticles on large-area single-layer graphene is still a challenge. Here, we report an in situ preparation of carbon nano-onion-encapsulated Fe nanoparticles on rebar graphene, which we term rivet graphene. The hybrid film, which allows for polymer-free transfer and is strong enough to float on water with no added supports, exhibits high optical transparency, excellent electric conductivity, and good hole/electron mobility under certain tensile/compressive strains. The results of contact resistance and transfer length indicate that the current in the rivet graphene transistor does not just flow at the contact edge. Carbon nano-onions encapsulating Fe nanoparticles on the surface enhance the injection of charge between rivet graphene and the metal electrode. The anchoring of Fe nanoparticles encapsulated by carbon nano-onions on rebar graphene will provide additional avenues for applications of nanocarbon-based films in transparent and flexible electronics.

Strong modulation of plasmons in Graphene with the use of an Inverted pyramid array diffraction grating

An optical device configuration allowing efficient electrical tuning of surface plasmon wavelength and absorption in a suspended/conformal graphene film is reported. An underlying 2-dimensional array of inverted rectangular pyramids greatly enhances optical coupling to the graphene film. In contrast to devices utilising 1D grating or Kretchman prism coupling configurations, both s and p polarization can excite plasmons due to symmetry of the grating structure. Additionally, the excited high frequency plasmon mode has a wavelength independent of incident photon angle allowing multidirectional coupling. By combining analytical methods with Rigorous Coupled-Wave Analysis, absorption of plasmons is mapped over near infrared spectral range as a function of chemical potential. Strong control over both plasmon wavelength and strength is provided by an ionic gel gate configuration. 0.04eV change in chemical potential increases plasmon energy by 0.05 eV shifting plasmon wavelength towards the visible, and providing enhancement in plasmon absorption. Most importantly, plasmon excitation can be dynamically switched off by lowering the chemical potential and moving from the intra-band to the inter-band transition region. Ability to electrically tune plasmon properties can be utilized in applications such as on-chip light modulation, photonic logic gates, optical interconnect and sensing applications.

Graphene-Based Flexible and Stretchable Electronics

Graphene provides outstanding properties that can be integrated into various flexible and stretchable electronic devices in a conventional, scalable fashion. The mechanical, electrical, and optical properties of graphene make it an attractive candidate for applications in electronics, energy-harvesting devices, sensors, and other systems. Recent research progress on graphene-based flexible and stretchable electronics is reviewed here. The production and fabrication methods used for target device applications are first briefly discussed. Then, the various types of flexible and stretchable electronic devices that are enabled by graphene are discussed, including logic devices, energy-harvesting devices, sensors, and bioinspired devices. The results represent important steps in the development of graphene-based electronics that could find applications in the area of flexible and stretchable electronics.

Highly Flexible and High-Performance Complementary Inverters of Large-Area Transition Metal Dichalcogenide Monolayers

Complementary inverters constructed from large-area monolayers of WSe2 and MoS2 achieve excellent logic swings and yield an extremely high gain, large total noise margin, low power consumption, and good switching speed. Moreover, the WSe2 complementary-like inverters built on plastic substrates exhibit high mechanical stability. The results provide a path toward large-area flexible electronics.

Broadly tunable graphene plasmons using an ion-gel top gate with low control voltage

The electrostatic tunability of graphene is vital in the field of active plasmons and would be beneficial in tunable infrared and terahertz optical element applications. The key to realizing broad tunability is achieving high carrier densities in graphene. Here we use an ion-gel, currently one of the most efficient dielectrics with ultra-high capacitance, to realize broadly tunable graphene plasmons (∼1270 cm(-1)) with low voltage modulation (∼4 V shifted from the Dirac point). We further explore the coupling between graphene plasmons and the molecular vibration modes of the ion-gel, since strong plasmon-phonon coupling can split the plasmon resonance peak into multi-peaks and reduce their tunability. Our experiments demonstrate weak plasmon-phonon coupling in the graphene/ion-gel system, which has limited effects on plasmon properties. These properties make ion-gels an effective dielectric for broadly tunable graphene plasmonic devices, such as new optical modulators, filters and wavelength multiplexers.

Electrolyte-gated graphene Schottky barrier transistors

A new device architecture for flexible vertical Schottky barrier (SB) transistors and logic gates based on graphene-organic-semiconductor-metal heterostructures and ion gel gate dielectrics is demonstrated. The devices show well-behaved p- and n-type characteristics under low-voltage operation (<1 V), yielding high current densities (>100 mA cm(-2) ) and on/off current ratios (>10(3) ).

Flexible transparent iontronic film for interfacial capacitive pressure sensing

A flexible, transparent iontronic film is introduced as a thin-film capacitive sensing material for emerging wearable and health-monitoring applications. Utilizing the capacitive interface at the ionic-electronic contact, the iontronic film sensor offers a large unit-area capacitance (of 5.4 μF cm(-2) ) and an ultrahigh sensitivity (of 3.1 nF kPa(-1) ), which is a thousand times greater than that of traditional solid-state counterparts.

Apparent pH sensitivity of solution-gated graphene transistors

Solution-gated graphene transistors were developed recently for use in pH sensor applications. The device operation is understood to rely on the capability of hydronium and hydroxide ions in solution to change the electrical properties of graphene. However, hydronium and hydroxide ions are accompanied by other ionic species in a typical acidic or basic solution and, therefore, the roles of these other ionic species must be also considered to fully understand the pH response of such devices. Using series of pH buffer solutions designed carefully, we verified that the magnitude and even the direction of pH-dependent Dirac voltage (VDirac) shift (the typical pH sensing indicator) depend strongly on the concentration and composition of the buffers used. The results indicate that the interpretation of the apparent pH-dependent VDirac response of a solution-gated graphene transistor must include the contributions of the additional ions in the solution.

Air-stable, high-performance, flexible microsupercapacitor with patterned ionogel electrolyte

We describe the fabrication of air-stable, high-performance, planar microsupercapacitors (MSCs) on a flexible poly(ethylene terephthalate) substrate with patterned ionogel electrolyte, i.e., poly(ethylene glycol) diacrylate/1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and electrodes of spray-coated multiwalled carbon nanotubes. The flexible MSC showed good cyclability, retaining ∼80% of initial capacitance after 30 000 cycles, and good mechanical stability down to a bending diameter of 3 mm under compressive stress; 95% of the initial capacitance was retained after 1000 bending cycles. The MSC had high electrochemical stability with retaining 90% of its initial capacitance for 8 weeks in air. Furthermore, vertical stacking of MSCs with patterned solid film of ionogel electrolyte could increase the areal capacitance dramatically. This flexible MSC has potential applications as an energy-storage device in micro/nanoelectronics, without encapsulation for air stability.

Modulation of the Dirac point voltage of graphene by ion-gel dielectrics and its application to soft electronic devices

We investigated systematic modulation of the Dirac point voltage of graphene transistors by changing the type of ionic liquid used as a main gate dielectric component. Ion gels were formed from ionic liquids and a non-triblock-copolymer-based binder involving UV irradiation. With a fixed cation (anion), the Dirac point voltage shifted to a higher voltage as the size of anion (cation) increased. Mechanisms for modulation of the Dirac point voltage of graphene transistors by designing ionic liquids were fully understood using molecular dynamics simulations, which excellently matched our experimental results. It was found that the ion sizes and molecular structures play an essential role in the modulation of the Dirac point voltage of the graphene. Through control of the position of their Dirac point voltages on the basis of our findings, complementary metal-oxide-semiconductor (CMOS)-like graphene-based inverters using two different ionic liquids worked perfectly even at a very low source voltage (V(DD) = 1 mV), which was not possible for previous works. These results can be broadly applied in the development of low-power-consumption, flexible/stretchable, CMOS-like graphene-based electronic devices in the future.

Transparent, low-power pressure sensor matrix based on coplanar-gate graphene transistors

A novel device architecture for preparing a transparent and low-voltage graphene pressure-sensor matrix on plastic and rubber substrates is demonstrated. The coplanar gate configuration of the graphene transistor enables a simplified procedure. The resulting devices exhibit excellent device performance, including a high transparency of ca. 80% in the visible range, a low operating voltage less than 2 V, a high pressure sensitivity of 0.12 kPa(-1) , and excellent mechanical durability over 2500 cycles.

Solution-processable electrochemiluminescent ion gels for flexible, low-voltage, emissive displays on plastic

Ion gels comprising ABA triblock copolymers and ionic liquids have received much attention as functional materials in numerous applications, especially as gate dielectrics in organic transistors. Here we have expanded the functionality of ion gels by demonstrating low-voltage, flexible electrochemiluminescent (ECL) devices using patterned ion gels containing redox-active luminophores. The ECL devices consisted only of a 30 μm thick emissive gel and two electrodes and were fabricated on indium tin oxide-coated substrates (e.g., polyester) simply by solution-casting the ECL gel and brush-painting a top Ag electrode. The triblock copolymer employed in the gel was polystyrene-block-poly(methyl methacrylate)-block-polystyrene, where the solvophobic polystyrene end blocks associate into micellar cross-links in the versatile ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). An ECL gel containing ~6.25 wt % Ru(bpy)3Cl2 (relative to [EMI][TFSI]) as the luminophore turned on at an AC peak-to-peak voltage as low as 2.6 V (i.e., -1.3 to +1.3 V) and showed a relatively rapid response (sub-ms). The wavelength of maximum emission was 610 nm (red-orange). With the use of an iridium(III) complex, Ir(diFppy)2(bpy)PF6 [diFppy = 2-(2',4'-difluorophenyl)pyridine; bpy = 2,2'-bipyridyl], the emitting color was tuned to a maximum wavelength of 540 nm (green). Moreover, when a blended luminophore system containing a 60:40 mixture of Ru(bpy)3(2+) and Ir(diFppy)2(bpy)(+) was used in the emissive layer, the luminance of red-orange-colored light was enhanced by a factor of 2, which is explained by the generation of the additional excited state Ru(bpy)3(2+)* by a coreactant pathway with Ir(diFppy)2(bpy)(+)* in addition to the usual annihilation pathway. This is the first time that enhanced ECL has been achieved in ion gels (or ionic liquids) using a coreactant. Overall, the results indicate that ECL ion gels are attractive multifunctional materials for printed electronics.