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Semiconducting polymers are promising materials for manufacturing optoelectronic devices, such as large-area solar cells or small light-emitting diodes, through the use of printing technologies. In their oxidized form, pi-conjugated polymers become good electrical conductors and their optical absorption shifts to the infrared region. It is demonstrated that conducting polymers can be integrated in bolometers for IR detection. A bolometer is a thermally isolated thin device that absorbs IR radiation and translates a temperature change into a change in electrical resistance. While commercial bolometers are usually made of complex architectures comprising several materials (that is, an IR absorbing layer, a conducting layer, and a thermally insulating layer), the first polymer bolometer is demonstrated with a freestanding layer of poly(3,4-ethylene-dioxythiophene) having high IR absorption, low thermal conductivity, and good thermistor action in one single layer. The solution processability of conducting polymers, their compatibility with high-resolution printing technologies, and their unique combination of optoelectronic properties can lead to a breakthrough for low-cost uncooled IR cameras, which are in high demand for security and safety applications., Funding Agencies|Knut and Alice Wallenberg Foundation (Tail of the Sun); Swedish Energy Agency; Swedish Research Council; AForsk; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; U.S. National Science Foundation [DMR-1262261]

A free-standing high-output power density polymeric thermoelectric (TE) device is realized based on a highly conductive (approximate to 2500 S cm(-1)) structure-ordered poly(3,4-ethylenedioxythiophene):polystyrene sulfonate film (denoted as FS-PEDOT:PSS) with a Seebeck coefficient of 20.6 mu V K-1, an in-plane thermal conductivity of 0.64 W m(-1) K-1, and a peak power factor of 107 mu W K-2 m(-1) at room temperature. Under a small temperature gradient of 29 K, the TE device demonstrates a maximum output power density of 99 +/- 18.7 mu W cm(-2), which is the highest value achieved in pristine PEDOT:PSS based TE devices. In addition, a fivefold output power is demonstrated by series connecting five devices into a flexible thermoelectric module. The simplicity of assembling the films into flexible thermoelectric modules, the low out-of-plane thermal conductivity of 0.27 W m(-1) K-1, and free-standing feature indicates the potential to integrate the FS-PEDOT:PSS TE modules with textiles to power wearable electronics by harvesting human bodys heat. In addition to the high power factor, the high thermal stability of the FS-PEDOT:PSS films up to 250 degrees C is confirmed by in situ temperature-dependent X-ray diffraction and grazing incident wide angle X-ray scattering, which makes the FS-PEDOT:PSS films promising candidates for thermoelectric applications., Funding Agencies|Vinnova Marie Curie incoming project [2016-04112]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [200900971]; Recruitment Program of Global Youth Experts; National Natural Science Foundation of China [21474035]; United States National Science Foundation [DMR-1262261]; Open Fund of the State Key Laboratory of Luminescent Materials and Devices [2016-skllmd-03]; European Research Council [ERC 307596]

Ionic thermoelectric materials, such as polyelectrolyte like polystyrene sulfonate sodium (PSSNa), constitute a new class ofmaterial attracting interest due to their large Seebeck coefficient and the possibility to be used in ionic thermoelectricsupercapacitors (ITESCs) and field effect transistors. However pure polyelectrolyte membranes are not robust neitherflexible. In this article, we demonstrate the preparation of ionic thermoelectric paper by a simple, scalable and cost-effectivemethod. After composite with nanofibrillated cellulose (NFC), the resulting NFC-PSSNa paper is flexible and mechanicallyrobust; which is desirable of using roll-to-roll processes. The robust thermoelectric paper NFC-PSSNa combines high ionicconductivity (9 mS/cm), high ionic Seebeck coefficient (8.4 mV/K) and low thermal conductivity (0.75 Wm-1K-1) at 100 RH%,resulting in overall figure-of-merit of 0.025 at room temperature slightly better than the PSSNa. Enabling flexibility androbustness by compositing with cellulose constitutes an advance for scaling up the manufacturing of ionic thermoelectricsupercapacitors; but also enables new applications for conformable thermoelectric devices and flexible electronics, Funding agencies: European Research Council (ERC Starting Grant) [307596]; Swedish Foundation for Strategic Research (SSF); Knut and Alice Wallenberg foundation (KAW); Swedish Energy Agency; Advanced Functional Materials Centre at Linkoping University; United States Nation

A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors., QC 20160319

A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors.

Exploiting the nanoscale properties of certain materials enables the creation of new materials with a unique set of properties. Here, we report on an electronic (and ionic) conducting paper based on cellulose nanofibrils (CNF) composited with poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), which may be facilely processed into large three-dimensional geometries, while keeping unprecedented electronic and ionic conductivities of 140 S/cm and 20 mS/cm, respectively. This is achieved by cladding the CNF with PEDOT:PSS, and trapping an ion-transporting phase in the interstices between these nanofibrils. The unique properties of the resulting nanopaper composite have been used to demonstrate (electrochemical) transistors, supercapacitors and conductors resulting in exceptionally high device parameters, such as an associated transconductance, charge storage capacity and current level beyond 1 S, 1 F and 1 A, respectively.