Double-layer Devices Research Articles

Multilayer organic photovoltaic devices fabricated by electrospray deposition technique and the role of the interlayer

Multilayer organic photovoltaic (OPV) devices were fabricated using the electrospray deposition method. The film-formation conditions and particularly the solvent composition were investigated to reveal the importance of the boiling point and polarity of the component solvents. The deposited film must be semi-wet to form a flat film by slow-drying at ambient conditions, resulting from the high boiling point and high affinity of o-dichlorobenzene for poly(3-hexylthiophene) (P3HT) and [6,6]-C70-butyric acid methyl ester (PC70BM). On the other hand, a polar solvent assists in the formation of an electrospray with a wide spray range under an applied voltage. Employing the film formation conditions, double-layered (P3HT and PC70BM) and triple-layered (P3HT, interlayer, and PC70BM) OPV devices were fabricated. A diketopyrrolopyrrole derivative, which is a near-infrared-absorbing ambipolar semiconductor, was applied as the interlayer material. By comparing the two devices, it was determined that the interlayer acts as a sensitizer at around 700nm for the P3HT–PC70BM system.

Enhancement of resistive switching properties in nitride based CBRAM device by inserting an Al2O3 thin layer

In this letter, we propose a method to enhance resistive switching properties in SiCN-based conductive-bridge resistive switching memory (CBRAM) devices by inserting a thin Al2O3 layer between the SiCN resistive switching layer and the TiN bottom electrode. Compared with the Cu/Ta/SiCN/TiN single-layer device, the Cu/Ta/SiCN/Al2O3/TiN double layer device exhibits uniform resistive switching, long stable endurance cycles (>1.6 × 104), and stable retention (104 s) at 125 °C. These substantial improvements in the resistive switching properties are attributed to the location of the formation and rupture of conductive filaments that can be precisely controlled in the device after introducing the Al2O3 layer. Moreover, a multilevel resistive switching characteristic is observed in the Cu/Ta/SiCN/Al2O3/TiN double layer CBRAM device. The distinct six-level resistance states are obtained in double layer devices by varying the compliance current. The highly stable retention characteristics (>104) of the Cu/Ta/SiCN/Al2O3/TiN double layer device with multilevel resistance states are also demonstrated.

Multifunctional Materials for High-Performance Double-Layer Organic Light-Emitting Diodes: Comparison of Isomers with and without Thermally Activated Delayed Fluorescence.

Organic light-emitting diodes (OLEDs) with simple structures are attracting a lot of attention nowadays, though their performances are always inferior to those of the more complicated structures as multifunctional materials are rare. Here, we have designed and synthesized multifunctional isomers by combining electron-donating carbazole (Cz) and triphenylamine (TPA) units with electron-accepting triazine (Trz), namely, N-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-[1,1'-biphenyl]-4-amine (CzTPA-p-Trz) and N-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-[1,1'-biphenyl]-4-amine (CzTPA-m-Trz). The use of multiple electron-donating groups gives them suitable highest occupied molecular orbitals for hole injection and high mobilities for hole transport. Hole-only devices with CzTPA-m-Trz or CzTPA-p-Trz as the hole injection layers and hole transport layers show a higher hole current than the widely used 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile/4,4'-N,N'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl system. Interestingly, CzTPA-p-Trz is a fluorescent material with a high photoluminescence quantum yield (PLQY), while CzTPA-m-Trz shows weak thermally activated delayed fluorescence (TADF). As expected, a CzTPA-p-Trz-based undoped double-layer green device achieved a higher external quantum efficiency (EQE) of 4.4% and a higher power efficiency (PE) of 11.8 lm/W. On the other hand, among double-layer devices doped with an orange phosphorescent dopant, a device based on TADF material, CzTPA-m-Trz, achieved higher peak EQE (23.5%) and PE (68.3 lm/W) than those of CzTPA-p-Trz (20.8% and 60.2 lm/W). Even at a high luminance of 5000 cd m-2, a high EQE of 21.8% was retained for CzTPA-m-Trz-based devices. These results are even comparable to those for the state-of-the-art phosphorescent devices based on the same dopant with more complicated structures. The above results indicate that well-designed multifunctional materials are promising for high-performance OLEDs with simple structures.

Enhanced electrical properties of oxide semiconductor thin-film transistors with high conductivity thin layer insertion for the channel region

This study examined the performance and the stability of indium tin zinc oxide (ITZO) thin film transistors (TFTs) by inserting an ultra-thin indium tin oxide (ITO) layer at the active/insulator interface. The electrical properties of the double channel device (ITO thickness of 5nm) were improved in comparison with the single channel ITZO or ITO devices. The TFT characteristics of the device with an ITO thickness of less than 5nm were degraded due to the formation of an island-like morphology and the carriers scattering at the active/insulator interface. The 5 nm-thick ITO inserted ITZO TFTs (optimal condition) exhibited a superior field effect mobility (∼95cm2/V·s) compared with the ITZO-only TFTs (∼34cm2/V·s). The best characteristics of the TFT devices with double channel layer are due to the lowest surface roughness (0.14nm) and contact angle (50.1°) that result in the highest hydrophicility, and the most effective adhesion at the surface. Furthermore, the threshold voltage shifts for the ITO/ITZO double layer device decreased to 0.80 and −2.39V compared with 6.10 and −6.79V (for the ITZO only device) under positive and negative bias stress, respectively. The falling rates of EA were 0.38eV/V and 0.54eV/V for the ITZO and ITO/ITZO bi-layer devices, respectively. The faster falling rate of the double channel devices suggests that the trap density, including interface trap and semiconductor bulk trap, can be decreased by the ion insertion of a very thin ITO film into the ITZO/SiO2 reference device. These results demonstrate that the double active layer TFT can potentially be applied to the flat panel display.

(Invited) Ferrocene-Modified Electroactive Ionic Liquids to Prevent Self-Discharge of Redox-Active Electrolyte Capacitors

Introduction: Redox-active electrolyte supercapacitors (RESC) are obtained by dissolving electroactive species in the electrolyte as a mean to increase the energy density of carbon-based capacitors.[1-3] RESCs are most often using aqueous electrolytes due to a higher solubility of redox molecules in water compared to organic solvents. For the same reason, ionic liquids (ILs) have not been extensively studied as electrolyte in RESCs despite the fact that they could present the advantage of an increased maximum operating voltage. So far, a compromise must be done between fast transport and high solubility of the redox molecule (obtained in aqueous electrolytes) and a high cell voltage (obtained with organic solvents and ionic liquids). RESCs may benefit from the development of electroactive electrolytes specifically formulated for this purpose, and which should i) allow high concentrations in redox species, ii) present a high maximum voltage, and iii)include a self-discharge suppression mechanism. This work demonstrates that electroactive ionic liquids, in which a redox moiety is covalently linked to one of the ions, may be used to meet these challenges. Experimental: Electroactive ILs were obtained by modifying the common ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, [EMIm][NTf2], with ferrocene. The ferrocene redox unit was linked either to the cation ([FcEIm][NTf2]) or the anion ([EMIm][FcNTf]) (Fig. 1). The ionic liquids were then used as the electrolyte in symmetrical cells using activated carbon (80 wt.%) as the active material. The cells were studied to evaluate the energy density and self-discharge to evaluate the effect of the ionic liquid structure on performance. Results and discussion: Cyclic voltammetry was used in first place to evaluate the response of the cells containing an electrolyte composed of 80 wt.% of either [EMIm][NTf2], [FcEIm][NTf2] or [EMIm][FcNTf] ILs in acetonitrile. The oxidation and reduction of the ferrocenyl unit on the IL results in the presence of peaks on the CV curves (Fig. 1). These faradaic reactions increase the amount of energy stored in the device by accumulating charges in the electrolyte which is a the heart of redox-active electrolyte supercapacitors. Galvanostatic charge-discharge (GCD) experiments were carried out to evaluate the energy density of the devices employing the electroactive ionic liquids. The gravimetric specific energy values, based on total weight of both electrodes for the RESCs presented here, are (at I = 2 mA) 13.2 and 9.0 Wh kg-1 for [EMIm][FcNTf] and [FcEIm][NTf2], respectively. These values represent a significant increase from equivalent double-layer devices using either the unmodified ionic liquid [EMIm][NTf2] (Wg = 7.2 Wh kg-1) or the conventional electrolyte 1 M TBAP in CH3CN (Wg = 6.4 Wh kg-1). Self-discharge (SDC) represents a major issue with RESCs because a shuttle discharge mechanism (reduction oxidized species at the negative electrode) adds up to the diffusion-based SDC.[4] The profiles of individual electrodes demonstrate that after an initial decrease due to ohmic drop, the potential of the positive electrode remained constant for three hours. SDC suppression in RESC based on redox IL with the Fc-modified anion is explained by the formation of a film at the positive electrode upon oxidation of [FcNTf]- to [Fc+NTf-]0that prevent the shuttling of the charged species to the negative electrode. Conclusions: The functionalization of an ionic liquid with ferrocene led to high concentrations of redox moieties in the electrolyte (2.4 M) and a large maximum operating voltage (2.5 V). An energy density of up to 13.2 Wh per kg (both electrodes) was obtained which represents an 83 % increase vs. the unmodified ionic liquid. When the ionic liquid’s anion is modified with ferrocene, the self-discharge at the positive electrode is fully suppressed due to the deposition of a film on the electrode. While the rate dependency of the specific energy and stability could be improved, these findings suggest that electroactive ionic liquids are particularly well-suited for use in redox-active electrolyte supercapacitors. References 1) E. Frackowiak et al. Chemsuschem, 5 (2012) 1181-1185; 2) S. Roldan et al. Angew. Chem. Int. Ed., 50 (2011) 1699-1701; 3) S.T. Senthilkumar et al. J. Mater. Chem. A, 1 (2013) 12386-12394; 4) L.B. Chen et al. Energy Environ. Sci., 7 (2014) 1750-1759. Figure 1

Incidence of New Ischaemic Brain Lesions After Carotid Artery Stenting with the Micromesh Roadsaver Carotid Artery Stent: A Prospective Single-Centre Study.

Several randomized trials of patients with carotid stenosis show increased adverse neurological events with stenting versus endarterectomy in the 30-day post-procedure. This study examines the incidence of new ischaemic lesions in patients treated in our centre using the new Roadsaver stent. Between September 2015 and January 2016, 23 consecutive patients (age 74.3±7.3years, 17.4% female) underwent carotid artery stenting with the Roadsaver stent, a nitinol double-layer micromesh device. A distal protection device was used in all cases. Diffusion-weighted magnetic resonance imaging was performed 24h before, and 24h and 30days after the procedure. The 24-h post-procedure imaging showed 15 new ipsilateral ischaemic lesions in 7 (30.4%) patients: median volume 0.076cm3 (interquartile range 0.065-0.146cm3). All lesions were asymptomatic. The 30-day imaging showed complete resolution of all lesions and no new ischaemic lesions. Follow-up clinical and ultrasound examinations at 30days and 6months recorded no adverse cardiac or cerebrovascular events. Protected stenting with micromesh Roadsaver stent showed good safety and efficacy in the treatment of carotid stenosis, with a low incidence of delayed embolic events and new ipsilateral ischaemic brain lesions. These preliminary results are encouraging, but need to be confirmed with larger populations.

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. Herein, we introduce a microfluidic-based technology, employing a double-layer microfluidic device, which can trap and localize in situ and ex situ synthesized structures on microfluidic channel surfaces. Crucially, we show how such a device can be used to conduct controlled chemical reactions onto on-chip trapped structures and we demonstrate how the synthetic pathway of a crystalline molecular material and its positioning inside a microfluidic channel can be precisely modified with this technology. This approach provides new opportunities for the controlled assembly of structures on surface and for their subsequent treatment.

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment.

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. Herein, we introduce a microfluidic-based technology, employing a double-layer microfluidic device, which can trap and localize in situ and ex situ synthesized structures on microfluidic channel surfaces. Crucially, we show how such a device can be used to conduct controlled chemical reactions onto on-chip trapped structures and we demonstrate how the synthetic pathway of a crystalline molecular material and its positioning inside a microfluidic channel can be precisely modified with this technology. This approach provides new opportunities for the controlled assembly of structures on surface and for their subsequent treatment.

Active plasmonic band-stop filters based on graphene metamaterial at THz wavelengths.

Active plasmonic band-stop filters based on single- and double-layer doped graphene metamaterials at the THz wavelengths are proposed and investigated numerically by using the finite-difference time-domain (FDTD) method. The metamaterial unit cell structure is composed of two parallel graphene nanoscale ribbons. Simulated results exhibit that significant resonance wavelength shifts can be achieved with a slight variation of the doping concentration of the graphene ribbons. Besides, the asymmetry double-layer graphene metamaterial device has two apparent filter dips while the symmetry single-, double-layer and asymmetry single-layer graphene metamaterial devices just only one. The metamaterials with symmetry single-layer and asymmetry double-layer graphene can be used as a high-sensitivity refractive sensor with the sensitivity up to 5100 nm/RIU and a two-circuit switch, respectively. These prospects pave the way towards ultrafast active graphene-based plasmonic devices for THz applications.

Helicenes as All-in-One Organic Materials for Application in OLEDs: Synthesis and Diverse Applications of Carbo- and Aza[5]helical Diamines.

A set of eight helical diamines were designed and synthesized to demonstrate their relevance as all-in-one materials for multifarious applications in organic light-emitting diodes (OLEDs), that is, as hole-transporting materials (HTMs), EMs, bifunctional hole transporting + emissive materials, and host materials. Azahelical diamines function very well as HTMs. Indeed, with high Tg values (127-214 °C), they are superior alternatives to popular N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB). All the helical diamines exhibit emissive properties when employed in nondoped as well as doped devices, the performance characteristics being superior in the latter. One of the carbohelical diamines (CHTPA) serves the dual function of hole transport as well as emission in simple double-layer devices; the efficiencies observed were better by quite some margin than those of other emissive helicenes reported. The twisting endows helical diamines with significantly high triplet energies such that they also function as host materials for red and green phosphors, that is, [Ir(btp)2 acac] (btp=2-(2'-benzothienyl)pyridine; acac=acetylacetonate) and [Ir(ppy)3 ] (ppy=2-phenylpyridine), respectively. The results of device fabrications demonstrate how helicity/ helical scaffold may be diligently exploited to create molecular systems for maneuvering diverse applications in OLEDs.

Enhanced Electrochemical Performance of Ultracentrifugation-Derived nc-Li3VO4/MWCNT Composites for Hybrid Supercapacitors.

Nanocrystalline Li3VO4 dispersed within multiwalled carbon nanotubes (MWCNTs) was prepared using an ultracentrifugation (uc) process and electrochemically characterized in Li-containing electrolyte. When charged and discharged down to 0.1 V vs Li, the material reached 330 mAh g(-1) (per composite) at an average voltage of about 1.0 V vs Li, with more than 50% capacity retention at a high current density of 20 A g(-1). This current corresponds to a nearly 500C rate (7.2 s) for a porous carbon electrode normally used in electric double-layer capacitor devices (1C = 40 mA g(-1) per activated carbon). The irreversible structure transformation during the first lithiation, assimilated as an activation process, was elucidated by careful investigation of in operando X-ray diffraction and X-ray absorption fine structure measurements. The activation process switches the reaction mechanism from a slow "two-phase" to a fast "solid-solution" in a limited voltage range (2.5-0.76 V vs Li), still keeping the capacity as high as 115 mAh g(-1) (per composite). The uc-Li3VO4 composite operated in this potential range after the activation process allows fast Li(+) intercalation/deintercalation with a small voltage hysteresis, leading to higher energy efficiency. It offers a promising alternative to replace high-rate Li4Ti5O12 electrodes in hybrid supercapacitor applications.

Improved Mobility and Bias Stability of Thin Film Transistors Using the Double-Layer a-InGaZnO/a-InGaZnO:N Channel.

The amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) were demonstrated based on a double-layer channel structure, where the channel is composed of an ultrathin nitro-genated a-IGZO (a-IGZO:N) layer and an undoped a-IGZO layer. The double-layer channel device showed higher saturation mobility and lower threshold-voltage shift (5.74 cm2/Vs, 2.6 V) compared to its single-layer counterpart (0.17 cm2/Vs, 7.23 V). The improvement can be attributed to three aspects: (1) improved carrier transport properties of the channel by the a-IGZO:N layer with high carrier mobility and the a-IGZO layer with high carrier concentration, (2) reduced interfacial trap density between the active channel and the gate insulator, and (3) higher surface flatness of the double-layer channel. Our study reveals key insights into double-layer channel, involving selecting more suitable electrical property for back-channel layer and more suitable interface modification for active layer. Meanwhile, room temperature fabrication amorphous TFTs offer certain advantages on better flexibility and higher uniformity over a large area.

Coexistence of bipolar and unipolar resistive switching behaviors in the double-layer Ag/ZnS-Ag/CuAlO2/Pt memory device

The coexistence of uniform bipolar and unipolar resistive-switching (RS) characteristics was demonstrated in a double-layer Ag/ZnS-Ag/CuAlO2/Pt memory device. By changing the compliance current (CC) from 1mA to 10mA, the RS behavior can be converted from the bipolar mode (BRS) to the unipolar mode (URS). The temperature dependence of low resistance states further indicates that the CFs are composed of the Ag atoms and Cu vacancies for the BRS mode and URS mode, respectively. For this double-layer structure device, the thicker conducting filaments (CFs) will be formed in the ZnS-Ag layer, and it can act as tip electrodes. Thus, the formation and rupture of these two different CFs are located in the CuAlO2 layer, realizing the uniform and stable BRS and URS.

Reversible electrochemical modulation of the superconducting transition temperature of LiTi2O4 ultrathin films by ionic liquid gating

We demonstrate in situ modulation of the superconducting transition temperature (Tc) of LiTi2O4 thin films by ionic liquid gating. 15 nm thick LiTi2O4 thin films grown on MgAl2O4 substrates with the pristine Tc of 11.5 K was patterned into electric double-layer transistor devices for gating using ionic liquid with or without Li+ ions. The Tc of the LiTi2O4 thin film was found to decrease with a negative gate voltage for gating with either pure ionic liquid or Li+ containing ionic liquid. On the other hand, the recovery of Tc is observed at a positive gate voltage only for gating with the Li+ containing ionic liquid. The present observation suggests the possibility of reversible electrochemical modulation of superconducting properties by lithiation and delithiation.

Tert-Butylated spirobifluorene derivative incorporating triphenylamine groups: A deep-blue emitter with high thermal stability and good hole transport ability for organic light emitting diode applications

A tert-butylated spirobifluorene derivative incorporating triphenylamine groups was synthesized starting from the readily available reagent biphenyl. Without any hole-transport layer, an unoptimized double-layer device exhibits excellent electroluminescent performances with a radiance of 3013 cd/m2 at 9.8 V, a maximum electroluminescent efficiency of 1.71 cd/A, a maximal external quantum efficiency of 2.58% at a brightness of 4.8 cd/m2, narrow full width at half-maximum (<54 nm), and blue emission with Commission Internationale de l'Eclairage coordinates of (0.152, 0.103), which is close to the standard for blue. Compared to the reported organic light emitting diodes materials, the molecule displays very high thermal stability. In addition, the bilayer device showed a greatly improved performance as compared to a trilayer device with NPB as hole-transporting layer, which indicated that the molecule possesses good hole transport ability and can be good candidate for hole-transporting layer in organic light emitting diodes.

Development of bipolar all-solid-state lithium battery based on quasi-solid-state electrolyte containing tetraglyme-LiTFSA equimolar complex.

The development of high energy–density lithium-ion secondary batteries as storage batteries in vehicles is attracting increasing attention. In this study, high-voltage bipolar stacked batteries with a quasi-solid-state electrolyte containing a Li-Glyme complex were prepared, and the performance of the device was evaluated. Via the successful production of double-layered and triple-layered high-voltage devices, it was confirmed that these stacked batteries operated properly without any internal short-circuits of a single cell within the package: Their plateau potentials (6.7 and 10.0 V, respectively) were two and three times that (3.4 V) of the single-layered device, respectively. Further, the double-layered device showed a capacity retention of 99% on the 200th cycle at 0.5 C, which is an indication of good cycling properties. These results suggest that bipolar stacked batteries with a quasi-solid-state electrolyte containing a Li-Glyme complex could readily produce a high voltage of 10 V.

Analysis of Carrier Transport of Organic Devices by Using Nonlinear Optical Polarization

In this review, we discuss the Maxwell-Wagner (MW) effect model analysis of organic devices and time-resolved optical second harmonic generation (TR-EFISHG) measurement that is available for directly probing carrier motion in organic semiconductor devices. Using these, we show that organic field effect transistor as well organic double-layer device operation is analyzed well, and we can make clear the mechanism of these organic devices' operation. Finally, we conclude that the dielectric physics approach using the MW model analysis and the TR-EFISHG experiment is useful to study carrier transport mechanism of organic devices.

Electric Double-Layer Capacitors Based on Multiwalled Carbon Nanotubes: Can Nanostructuring of the Nanotubes Enhance Performance?

Supercapacitors prepared from chemically modified and vacuum filtered buckypapers were studied. The aim was to evaluate how its pore structure impacts the specific capacitance, energy, and power density in different electrolytes. The specific capacitance varies in a linear fashion with the specific surface area for nanotubes modified by the means of catalytic, low-temperature partial catalytic oxidation using cobalt oxide nanoparticles decorating the nanotubes. In contrast, electrodes composed of nanotubes preactivated in CO2 demonstrated only a minor increase in their specific capacitance, despite the observed significant increase in specific surface area. The radically improved surface area was a result of emergence and deposition of soot on the nanotubes during the activation process, as revealed by transmission electron microscopy. Among six different types of electrode materials, the CoOx decorated materials proved to have the highest specific capacitance (∼25 F/g in aqueous KOH and ∼15 F/g in triethylsulfonium bis(trifluoromethylsulfonyl)imide ionic liquid). Thus, highly structured carbon nanotubes giving rise to energy and power storage densities comparable with commercial and other multiwalled carbon nanotube based electric double-layer capacitor devices were obtained.

Impedance spectroscopy: A method for determining the degree of intermixing in stacks of organic semiconductors

One of the main difficulties occurring in printed organic electronics is the intermixing between adjacent layers. This has to be quantified to optimise printed devices. Methods like sputter X‐ray photoelectron spectroscopy (XPS) are suitable for this, but also complex, expensive and destructive. We propose impedance spectroscopy as an alternative for quantifying the degree of intermixing non‐destructively. Here, after measuring a device's impedance spectrum its concentration profile is determined with a fit function. For this proof of concept we produced single and double layer samples of NPD and Alq3 with different interface widths by thermal evaporation. The concentration profiles were monitored with micro balances. The material parameters were extracted from single layer spectra and then set in a fit function used to determine the degree of intermixing in double layer devices. Even slight intermixing could be evaluated with this method and complete intermixing was detected as such. Due to the imprecise production of devices and certain simplifications used for this first test, the fit yielded too small interface widths, the deviation reaching almost 50%. The variation for devices produced in the same run was only about 10%, indicating that intermixing can be reliably quantified with impedance spectroscopy if the material's properties are accurately known.

Pressure-Temperature Phase Diagram of Ionic Liquid Dielectric DEME-TFSI

Ionic liquids have proven highly effective as dielectrics in Electric Double Layer (EDL) devices for electrostatic doping in a range of materials. DEME-TFSI in particular is a commonly used dielectric due to its high ionic conductivity and low glass transition temperature of 182K. Application of pressure provides a dual tuning parameter in tandem with the electric field yet progress is hampered by the lack of an accurate pressure-temperature phase diagram for DEME- TFSI. We present results on expansivity and leakage current measurements of the ionic liquid dielectric DEME-TFSI to provide a phase diagram mapping the glass transition temperature up to 0.6GPa. This should allow the effective operation of EDL devices using DEME-TFSI under pressure.