Direct Gravure Printing of Silicon Nanowires Using Entropic Attraction Forces

作者：Seo Jungmok; Lee Hyonik; Lee Seulah; Lee Tae Il; Myoung Jae Min; Lee Taeyoon

来源：Small, 2012, 8(10): 1614-1621.

DOI：10.1002/smll.201102367

• silicon
• nanowires
• gravure printing
• nanowire alignment
• flexible electronics
• entropic force fields

The development of a method for large-scale printing of nanowire (NW) arrays onto a desired substrate is crucial for fabricating high-performance NW-based electronics. Here, the alignment of highly ordered and dense silicon (Si) NW arrays at anisotropically etched micro-engraved structures is demonstrated using a simple evaporation process. During evaporation, entropic attraction combined with the internal flow of the NW solution induced the alignment of NWs at the corners of pre-defined structures, and the assembly characteristics of the NWs were highly dependent on the polarity of the NW solutions. After complete evaporation, the aligned NW arrays are subsequently transferred onto a flexible substrate with 95% selectivity using a direct gravure printing technique. As a proof-of-concept, flexible back-gated NW field-effect transistors (FETs) are fabricated. The fabricated FETs have an effective hole mobility of 17.1 cm2 center dot V-1 center dot s-1 and an on/off ratio of similar to 2.6 x 105.

• 出版日期2012-5-21