title: Silicon nanowires: electron holography studies of doped p-n junctions and biased Schottky barriers.
abstract: We report an in situ examination of individual Si p-n junction nanowires (NWs) using off-axis electron holography (EH) during transmission electron microscopy. The SiNWs were synthesized by chemical vapor deposition with an axial dopant profile from n- to p-type, and then placed inside the transmission electron microscope as a cantilever geometry in contact with a movable Pt probe for in situ biasing measurements during simultaneous EH observations. The phase shift from EH indicates the potential shift between the p- and n-segments to be 1.03 ± 0.17 V due to the built-in voltage. The I-V characteristics of a single SiNW indicate the formation of a Schottky barrier between the NW tip and the movable Pt contact. EH observations show a strong concentration of electric field at this contact, preventing a change in the Si energy bands in the p-n junction region due to the applied bias.
authors: Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA.
authors: Kai
authors: K
authors: He
authors: Jeong-Hyun
authors: JH
authors: Cho
authors: Yeonwoong
authors: Y
authors: Jung
authors: S Tom
authors: ST
authors: Picraux
authors: John
authors: J
authors: Cumings