Organic photovoltaics
Thin-fi lm single-wall carbon nanotubes (SWNTs) are attracting interest as high performance fl exible electrodes that can be processed at plastic-compatible temperatures ( < 150 Β° C), whilst offering a good balance of transparency, conductivity and work function that compares favourably with indium tin oxide. [1][2][3] SWNTs have been successfully used in many optoelectronic devices, including light-emitting diodes, [ 4 ] transistors, [ 5 ] and photovoltaic (PV) cells. [ 3 , 6 ] However, key technical challenges remain in several areas, in particular: improving fi lm uniformity; scaling-up to large-area manufacturing; and developing improved patterning techniques for array-based applications such as image sensors, displays, and PV modules. [2][3][4][5] A variety of techniques have been reported for patterning SWNTs, including: spatially selective electrochemical deposition, [ 2 ] vacuum fi ltration, [ 7 ] photoablation, [ 8 ] transfer printing, [ 5 , 9 ] and conventional photolithography. [ 10 , 11 ] However, existing methods suffer from a variety of limitations such as insuffi cient resolution, [ 2 , 9 ] poor scalability to large areas, [ 2 ] complex or inconvenient processing steps, [9][10][11] and/or process-induced damage of electronic properties. [ 11 ]