title: Direct gravure printing of silicon nanowires using entropic attraction forces.
abstract: 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 cm(2) ·V(-1) ·s(-1) and an on/off ratio of ~2.6 × 10(5) .
authors.affiliation: Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Gu, Seoul, Republic of Korea.
authors.forename: Jungmok
authors.initials: J
authors.lastname: Seo
authors.forename: Hyonik
authors.initials: H
authors.lastname: Lee
authors.forename: Seulah
authors.initials: S
authors.lastname: Lee
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Lee
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Myoung
authors.forename: Taeyoon
authors.initials: T
authors.lastname: Lee