title: Interaction range of P-dopants in Si[110] nanowires: determining the nondegenerate limit.
abstract: It is well known that the activation energy of dopants in semiconducting nanomaterials is higher than in bulk materials owing to dielectric mismatch and quantum confinement. This quenches the number of free charge carriers in nanomaterials. Though higher doping concentration can compensate for this effect, there is no clear criterion on what the doping concentration should be. Using P-doped Si[110] nanowires as the prototypical system, we address this issue by establishing a doping limit by first-principles electronic structure calculations. We examine how the doped nanowires respond to charging using an effective capacitance approach. As the nanowire gets thinner, the interaction range of the P dopants shortens and the doping concentration can increase concurrently. Hence, heavier doping can remain nondegenerate for thin nanowires.
authors.affiliation: Center for Computational Materials, Institute for Computational Engineering and Sciences, University of Texas , Austin, Texas 78712, United States.
authors.forename: Tzu-Liang
authors.initials: TL
authors.lastname: Chan
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Lee
authors.forename: Alex W K
authors.initials: AW
authors.lastname: Mok
authors.forename: James R
authors.initials: JR
authors.lastname: Chelikowsky
keywords: Doping; capacitance; first-principles electronic structure calculation; nanowire