title: Direct observation of the semimetal-to-semiconductor transition of individual single-crystal bismuth nanowires grown by on-film formation of nanowires.
abstract: We have systematically investigated the semimetal-to-semiconductor transition of individual single-crystalline Bi nanowires. For this work, we developed a technique to reduce the diameter of Bi nanowires grown by our unique on-film formation of nanowires (OFF-ON) method. Cooling down the substrate temperature during Bi film deposition by use of liquid nitrogen, film structures with small-sized grains were obtained. Through thermal annealing of these fine-granular Bi films, single-crystalline Bi nanowires can be produced with minimum diameter of approximately 20 nm. Elaborative nanofabrication techniques were employed to shape state-of-the-art four-probe devices based on the individual small diameter Bi nanowires. Diameter-dependent transport measurements on the individual Bi nanowires revealed that the semimetal-to-semiconductor transition really occurred at about d(w) = 63 nm. Moreover, band structure calculations supported this occurrence of the semimetal-to-semiconductor transition.
authors.affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul, Korea.
authors.forename: Seunghyun
authors.initials: S
authors.lastname: Lee
authors.forename: Jinhee
authors.initials: J
authors.lastname: Ham
authors.forename: Kyejin
authors.initials: K
authors.lastname: Jeon
authors.forename: Jin-Seo
authors.initials: JS
authors.lastname: Noh
authors.forename: Wooyoung
authors.initials: W
authors.lastname: Lee