In order to develop an excellent pseudocapacitor with both high specific capacitance and outstanding stretchability to match with other devices applicable in future wearable and bio-implantable systems, we focus our studies on three vital aspects: Stretchability of hybrid film electrodes, the interface between different components, and the integrated performance in stretchability and electrochemistry of supercapacitors based on single-walled carbon nanotube/polyaniline (SWCNT/PANI) composite films on pre-elongated elastomers. Owing to the moderate porosity, the buckled hybrid film avoids the cracking which occurs in conventional stretchable hybrid electrodes, and both a high specific capacitance of 435 F·g^-1 and a high strain tolerance of 140% have been achieved. The good SWCNT/PANI interfacial coupling and the reinforced solid electrolyte penetration structure enable the integrated pseudocapacitors to have stretch-resistant interfaces between different units and maintain a high performance under a stretching of 120% elongation, even after 1, 000 cyclic elongations.

Random networks of single-walled carbon nanotubes (SWCNTs) were have been grown by chemical vapor deposition on silicon wafers and used for fabricating field-effect transistors (FETs) using symmetric Pd contacts and diodes using asymmetrical Pd and Sc contacts. For a short channel FET or diode with a channel length of about 1 μm or less, the device works in the direct transport regime, while for a longer channel device the transport mechanism changes to percolation. Detailed electronic and photovoltaic (PV) characterizations of these carbon nanotube (CNT) thin-film devices was carried out. While as-fabricated FETs exhibited typical p-type transfer characteristics, with a large current ON/OFF ratio of more than 10⁴ when metallic CNTs were removed via a controlled breakdown, it was found that the threshold voltage for the devices was typically very large, of the order of about 10 V. This situation was greatly improved when the device was coated with a passivation layer of 12 nm HfO₂, which effectively moved the threshold voltages of both FET and diode back to center around zero or turned these device to their OFF states when no bias was applied on the gate. PV measurements were then made on the short channel diodes under infrared laser illumination. It was shown that under an illumination power density of 1.5 kW/cm², the device resulted in an open circuit voltage V_OC = 0.21 V and a short circuit current I_SC = 3.74 nA. Furthermore, we compared PV characteristics of CNT film diodes with different channel lengths, and found that the power transform efficiency decreased significantly when the device changed from the direct transport to the percolation regime.