High-performance transistors for bioelectronics through tuning of channel thickness

Rivnay, Jonathan; Leleux, Pierre; Ferro, Marc; Sessolo, Michele; Williamson, Adam; Koutsouras, Dimitrios A.; Khodagholy, Dion; Ramuz, Marc; Strakosas, Xenofon; Owens, Róisı́n M.; Bénar, Christian; Badier, Jean‐Michel; Bernard, Christophe; Malliaras, George G.

doi:10.1126/sciadv.1400251

Cited by 588 publications

(900 citation statements)

References 41 publications

Supporting

Mentioning

809

Contrasting

Unclassified

Order By: Relevance

“…Therefore, the volumetric response of the capacitance leads to a dependence of the transconductance on the channel dimension. [19] For a fixed device geometry, the thickness of the active layer can then be used to tune the transconductance, and hence the performance, of the device. Thick films of BBL, ranging from 40 to 180 nm, were prepared via spray-coating depositions of an aqueous BBL dispersion (details of the preparation steps can be found in the Experimental Section).…”

mentioning

confidence: 99%

“…A linear correlation is found between transconductance and active layer thickness (see Figure S4 of the Supporting Information), in agreement with previous reports. [19] The volumetric capacitance, as extracted from impedance measurements at different film thickness and V G = 0.5 V, is ≈930 ± 40 F cm −3 ( Figure S5, Supporting Information). Remarkably, this value exceeds more than twofold that of other NDI-based OECTs (≈400 F cm −3 ), [10] and is several orders of magnitude higher than that estimated for n-type electrolyte-gated field-effect transistors.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Complementary Logic Circuits Based on High‐Performance n‐Type Organic Electrochemical Transistors

et al. 2018

View full text Add to dashboard Cite

Organic electrochemical transistors (OECTs) have attracted great attention as they hold significant promise for a variety of applications ranging from printable logic circuits for electronic textiles to drivers for sensors and flat panel display pixels, as well as to artificial synapse for neuromorphic computing. [1] Because of the low working bias, high sensitivity, and stability in aqueous environments, as well as biological and mechanical compatibility with live tissues, OECTs have also recently emerged as a technological solution to a variety of diagnostic and therapeutic applications. [2] A considerable amount of work has focused, for example, on approaches exploiting the principle of OECTs for the development of biomedical tools for chemical and biological sensing, [3] electrophysiological recording, [4] monitoring of cell viability, and barrier tissue integrity, [5] to name just a few. In an OECT, the electroactive polymer constituting the channel is in direct contact with an electrolyte and with the source and drain metal electrodes ( Figure 1A). Because of the soft and permeable nature of the electroactive polymers, ions are able to penetrate into the bulk of the transistor channel. [6] The operation of an OECT relies then on a reversible ion exchange and charge compensation process, which leads to a bulk doping of the organic conducting channel and to a modulation of the electronic conductivity between the source and drain contacts. Hence, OECTs transduce a modulation in the gate voltage (V G ) to a modulation in the drain current (I D ) running through the entire bulk of the channel. The figure-of-merit that quantifies the efficiency of this transduction is the transconductance, defined as g m = ∂I D /∂V G .The current state-of-the-art active material for OECTs is the mixed ion-electron conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The volumetric doping and dedoping of PEDOT:PSS result in a modulation of the drain-source current of several orders of magnitude with a consequent high transconductance. [7] As PEDOT:PSS is doped in its pristine state, and thus highly conducting, the OECT operates in depletion mode. In addition, several polythiophene-based polymers have been reported as efficient electroactive channel materials for enhancement mode OECTs. [8] To date, however, essentially all reported OECTs have relied on hole transport (p-type), while the development of electron Organic electrochemical transistors (OECTs) have been the subject of intense research in recent years. To date, however, most of the reported OECTs rely entirely on p-type (hole transport) operation, while electron transporting (n-type) OECTs are rare. The combination of efficient and stable p-type and n-type OECTs would allow for the development of complementary circuits, dramatically advancing the sophistication of OECT-based technologies. Poor stability in air and aqueous electrolyte media, low electron mobility, and/or a lack of electrochemical reversibility, of available high-...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Complementary Logic Circuits Based on High‐Performance n‐Type Organic Electrochemical Transistors

et al. 2018

View full text Add to dashboard Cite

show abstract

“…It was recently shown that the capacitance of OECTs is volumetric in nature. 34,35 The implications are that g m is dependent on the thickness of the semiconductor and that the value of the effective capacitance per unit area C i used in equation 1 is a projected value of the capacitance per unit volume C * of the three-dimensional electrode defined by the bulk of the semiconductor channel, and not the interfacial double layer capacitance C DL = 20 µF cm −2 of the PIL/IL ion gel, that we obtained using a Au/ion gel/PEDOT:PSS stack via impedance spectroscopy. Here, we obtained averages of C i = 197±17 µF cm −2 and C * = 98±9 µF cm −3 .…”

mentioning

confidence: 99%

High performance photolithographically-patterned polymer thin-film transistors gated with an ionic liquid/poly(ionic liquid) blend ion gel

Thiburce

Porcarelli

Mecerreyes

et al. 2017

Applied Physics Letters

View full text Add to dashboard Cite

We demonstrate the fabrication of polymer thin-film transistors gated with an ion gel electrolyte made of the blend of an ionic liquid and a polymerised ionic liquid. The ion gel exhibits a high stability and ionic conductivity, combined with facile processing by simple drop-casting from solution. In order to avoid parasitic effects such as high hysteresis, high off-currents and slow switching, a fluorinated photoresist is employed in order to enable high-resolution orthogonal patterning of the polymer semiconductor over an area that precisely defines the transistor channel. The resulting devices exhibit excellent characteristics, with an on/off ratio of 10 6 , low hysteresis and a very large transconductance of 3 mS. We show that this high transconductance value is mostly the result of ions penetrating the polymer film and doping the entire volume of the semiconductor, yielding an effective capacitance per unit area of about 200 µF cm −2 , one order of magnitude higher than the double layer capacitance of the ion gel. This results in channel currents larger than 1 mA at an applied gate bias of only -1 V. We also investigate the dynamic performance of the devices and obtain a switching time of 20 ms, which is mostly limited by the overlap capacitance between the ion gel and the source and drain contacts.Electrolyte-gated organic thin-film transistors (OTFTs) have received a lot of attention over the past years, thanks to their ability to operate at very low voltages (< |1| V), 1-3 which makes them particularly attractive for use in portable devices powered by low supply voltage sources such as thin-film batteries, and interfacing with conventional Si CMOS electronics. If an electrolyte is placed in contact with two electrodes, to which a small voltage is applied, ionic species within the electrolyte migrate towards the electrode of opposite polarity, forming ultra-thin electrical double layers at both electrolyte/electrode interfaces. When one of these electrodes is the channel of a transistor, large charge densities arise within the semiconductor, as a result of the ionic accumulation within a small volume close to the interface or within the bulk of the semiconductor, depending on the mode of operation of the device. In the case where ionic charges are contained at the interface with the semiconductor, for example by using a polyelectrolyte in which the ionic charges are covalently linked to the polymer chains 4 or a crystalline semiconductor impermeable to ion penetration, 5 the device operates much like a field-effect transistor. On the other hand, when ions penetrate inside the bulk of a polymer semiconductor, the capacitance must be considered as a volumetric parameter and the doping process is electrochemical in nature, 6-8 resulting in very large currents flowing through the whole channel volume. As a) Electronic mail: alasdair.campbell@imperial.ac.uk a consequence, large transconductances surpassing that of silicon-based TFTs can be obtained, 9 even in OTFTs employing polymer semiconductors with modest ...

show abstract

“…Rivnay et al 5 recently measured electrochemical impedance spectra of PEDOT:PSS cast from dispersion to form films of different volumes. An equivalent circuit consisting of a capacitor and two resistors gave a good fit to the entire data set.…”

mentioning

confidence: 99%

Understanding volumetric capacitance in conducting polymers

Proctor

Rivnay

Malliaras

2016

J Polym Sci B Polym Phys

Self Cite

230

228

View full text Add to dashboard Cite

Recent measurements in poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films show that capacitance scales with film volume. We discuss the ramifications of this finding and propose a simple model that describes capacitance in terms of sites in which ions injected from the electrolyte replace holes that are extracted from the film by a metal contact. We propose that volumetric capacitance is inversely proportional to the average distance between these sites.

show abstract

High-performance transistors for bioelectronics through tuning of channel thickness

Abstract: Transistors with tunable transconductance allow high-quality recordings of human brain rhythms.

Cited by 588 publications

References 41 publications

Complementary Logic Circuits Based on High‐Performance n‐Type Organic Electrochemical Transistors

Complementary Logic Circuits Based on High‐Performance n‐Type Organic Electrochemical Transistors

High performance photolithographically-patterned polymer thin-film transistors gated with an ionic liquid/poly(ionic liquid) blend ion gel

Understanding volumetric capacitance in conducting polymers

Contact Info

Product

Resources

About