Aligned ultralong nanowire arrays and their application in flexible photodetector devices

Abstract

We develop a facile approach for the one-step growth of ultralong aligned copper phthalocyanine (CuPc) nanowire (NW) arrays in a large area, through a grating-assisted physical vapor deposition method. The grating serves as the alignment template that guides the oriented growth of NWs, however, the morphology of the NWs is not restricted by the template but is remarkably determined by the growth conditions. The resulting NW arrays possess rectangular cross-sections, ultralong length, perfect alignment and large uniformity, which hold great potential as promising blocks for future integrated devices. The mechanism of one-step growth and alignment of NW arrays has been well discussed. Transparent and flexible photoconductive devices based on the aligned NW arrays can be directly constructed on the grating, which exhibit a fast response speed, high stability and reproducibility. Transfer of the NW arrays from the grating for further applications, has also been achieved by using polydimethylsiloxane (PDMS) as an elastic stamp. Flexible and electrically stretchable NW devices have then been fabricated on PDMS and demonstrate superior performances. The ability to make large area ultralong flexible organic NW arrays opens new possibilities for integrated device applications of organic nanostructures.