Cross-sectional scanning-tunneling-spectroscopy of a-Si:H pn-doping superlattices

Journal article

Publication Details

Author(s): Hundhausen M, Ley L
Journal: Superlattices and Microstructures
Publisher: Elsevier
Publication year: 1994
Volume: 16
Pages range: 271
ISSN: 0749-6036


The electronic properties of amorphous hydrogenated silicon (a-Si:H) pn-doping-superlattices are investigated by cross-sectional current imaging tunneling spectroscopy (CITS) using a scanning tunneling microscope in dry nitrogen ambient. In the constant current mode a contrast between n- and p-type layers is found. In addition, the spatially resolved normalized differential conductivity is measured for different bias voltages applied to the sample with respect to the STM tip. For small bias voltage at which tunneling occurs between the tip and gap-states of the amorphous superlattice a contrast between p-type and n-type doped layers is observed in the normalized differential conductivity. This is in agreement with the different densities of states available for tunneling between the STM and the differently doped layers. However, the contrast is almost missing if a larger voltage is applied, so that tunneling mainly occurs between tip and sample band-states.

FAU Authors / FAU Editors

Hundhausen, Martin apl. Prof. Dr.
Lehrstuhl für Laserphysik
Ley, Lothar Prof. Dr.
Naturwissenschaftliche Fakultät

Last updated on 2018-09-08 at 04:53