The emergence of wearable electronics and optoelectronics requires the development of devices that are not only highly flexible but can also be woven into textiles to offer a truly integrated solution. Here, we report a colour-tunable, weavable fibre-shaped polymer light-emitting electrochemical cell (PLEC). The fibre-shaped PLEC is fabricated using all-solutionbased processes that can be scaled up for practical applications. The design has a coaxial structure comprising a modified metal wire cathode and a conducting aligned carbon nanotube sheet anode, with an electroluminescent polymer layer sandwiched between them. The fibre shape offers unique and promising advantages. For example, the luminance is independent of viewing angle, the fibre-shaped PLEC can provide a variety of different and tunable colours, it is lightweight, flexible and wearable, and it can potentially be woven into light-emitting clothes for the creation of smart fabrics. L ight-emitting electrochemical cells 1-6 , in particular polymer light-emitting electrochemical cells (PLECs), have been widely studied for various applications, including flexible flat panel displays, signage and lighting 4-6 . Like organic light-emitting diodes (OLEDs) and polymer light-emitting diodes (PLEDs), PLECs have a structure that is usually composed of two metal electrodes connected to an organic semiconductor. However, PLECs differ in that mobile ions are incorporated into the organic semiconductor, thereby offering promising advantages such as low operating voltage, high electron/photon conversion efficiency and high power efficiency compared with OLEDs 7-18 . More importantly, PLECs do not require the use of low-workfunction cathodes composed of calcium or magnesium (which are sensitive in air). In contrast, PLEDs require a low-workfunction cathode and high-workfunction anode to realize efficient charge injection 19-21 . In a typical PLEC, the electroluminescent polymer layer forms an in situ light-emitting p-i-n junction for the injection of both electrons and holes from the electrodes 4,5,22 . This means that PLECs can be effectively operated with relatively rougher surfaces than is generally possible with OLEDs and PLEDs, which is advantageous when scaling them up for practical applications with low cost and high efficiency 23-25 .Based on these described advantages, the PLEC is particularly promising for use in portable and wearable electronics, which are being developed for a wide range of applications, from microelectronics to biomedicine, transport and areospace 26-32 . Conventional planar light-emitting devices, including both rigid and flexible films, cannot satisfy the basic requirements for such an application, including softness, light weight and weavability 33,34 . To this end, advances in the textile industry have suggested a useful direction in which to pursue a solution: if a PLEC is made into a continuous fibre using a melting or all-solution-based process, it can be woven into various flexible textiles or integrated into soft substrates for u...

Light my wire: Aligned carbon nanotube (CNT) fibers are wrapped around a TiO2 nanowire that is several centimeters long. Treating the ends of the nanotube wire with a light‐sensitive dye and an electrolyte, creates photoelectric‐conversion and energy‐storage regions in the same device (see scheme). The “wire” shows a high overall photoelectric conversion and storage efficiency of 1.5 %.

The formation of composite materials represents an efficient route to improve the performances of polymers and expand their application scopes. Due to the unique structure and remarkable mechanical, electrical, thermal, optical and catalytic properties, carbon nanotube and graphene have been mostly studied as a second phase to produce high performance polymer composites. Although carbon nanotube and graphene share some advantages in both structure and property, they are also different in many aspects including synthesis of composite material, control in composite structure and interaction with polymer molecule. The resulting composite materials are distinguished in property to meet different applications. This review article mainly describes the preparation, structure, property and application of the two families of composite materials with an emphasis on the difference between them. Some general and effective strategies are summarized for the development of polymer composite materials based on carbon nanotube and graphene.

A stretchable, wearable dye-sensitized solar-cell textile is developed from elastic, electrically conducting fiber as a counter electrode and spring-like titanium wire as the working electrode. Dyesensitized solar cells are demonstrated with energy-conversion efficiencies up to 7.13%. The high energy-conversion efficiencies can be well maintained under stretch by 30% and after stretch for 20 cycles.

Aligned carbon nanotube sheets are developed as a new family of electrodes to fabricate dye-sensitized solar cells. The energy conversion efficiency of the resulting cell is higher than the randomly dispersed carbon nanotube film and comparable with the platinum. Novel and flexible solar cells can be easily made from such carbon nanotube sheets with high potentials.