Photocurrents in a Single InAs Nanowire/Silicon Heterojunction.
We investigate the optoelectronic properties of single indium arsenide nanowires, which are grown vertically on p-doped silicon substrates. We apply a scanning photocurrent microscopy to study the optoelectronic properties of the single heterojunctions. The measured photocurrent characteristics are consistent with an excess charge carrier transport through midgap trap states, which form at the Si/InAs heterojunctions. Namely, the trap states add an additional transport path across a heterojunction, and the charge of the defects changes the band bending at the junction. The bending gives rise to a photovoltaic effect at a small bias voltage. In addition, we observe a photoconductance effect within the InAs nanowires at large biases.
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.|Nanosystems Initiative Munich (NIM) , Schellingstr. 4, 80799 Munich, Germany.
Andreas
A
Brenneis
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.|Nanosystems Initiative Munich (NIM) , Schellingstr. 4, 80799 Munich, Germany.
Jan
J
Overbeck
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.
Julian
J
Treu
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.
Simon
S
Hertenberger
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.
Stefanie
S
Morkötter
Department of Chemistry, Ludwig Maximilians Universität München , Butenandtstr. 11, 81377 Munich, Germany.
Markus
M
Döblinger
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.|Nanosystems Initiative Munich (NIM) , Schellingstr. 4, 80799 Munich, Germany.
Jonathan J
JJ
Finley
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.|Institut for Advanced Study, Technische Universität München , Lichtenbergstrasse 2a, 85748 Garching, Germany.
Gerhard
G
Abstreiter
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.
Gregor
G
Koblmüller
Walter Schottky Institut and Physik-Department, Technische Universität München , Am Coulombwall 4a, 85748 Garching, Germany.|Nanosystems Initiative Munich (NIM) , Schellingstr. 4, 80799 Munich, Germany.
Alexander W
AW
Holleitner
heterojunctions; nanowires; optoelectronics; photocurrents; scanning photocurrent microscopy