Nonideal Diode Behavior and Bandgap Renormalization in Carbon Nanotube p-n Junctions

Author

Shun-Wen Chang ; Bergemann, Kevin ; Dhall, Rohan ; Zimmerman, Jeramy ; Forrest, Stephen ; Cronin, Stephen B.

Author_Institution

Phys. Dept., Univ. of Southern California, Los Angeles, CA, USA

Volume

13

Issue

1

fYear

2014

fDate

Jan. 2014

Firstpage

41

Lastpage

45

Abstract

The p-n junction diodes are formed by electrostatic doping using two gate electrodes positioned beneath individual, suspended single-walled carbon nanotubes (CNTs). These devices exhibit nearly ideal diode behavior within a small bias voltage range near 0 V. At higher bias (>vert 0.2 Vvert), nonideal diode behavior is observed arising from Schottky contacts formed between the nanotube and its metal contact electrodes and the presence of electron tunneling between the N- and P-doped regions. We introduce a back-to-back diode model to explain the observed current versus voltage (I-V) characteristics. The reverse saturation current, parallel resistance, and open-circuit voltage dependence on gate voltage provide quantitative evidence for the theoretically predicted doping-induced bandgap shrinkage in CNTs. The minority carrier lifetimes are also estimated from this model.

Keywords

Schottky barriers; Schottky diodes; carbon nanotubes; carrier lifetime; energy gap; minority carriers; p-n junctions; renormalisation; semiconductor doping; shrinkage; tunnelling; C; Schottky contacts; back-to-back diode model; bandgap renormalization; bias voltage; carbon nanotube p-n junctions; current-voltage characteristics; doping-induced bandgap shrinkage; electron tunneling; electrostatic doping; gate electrodes; gate voltage; metal contact electrodes; minority carrier lifetimes; n-doped region; nonideal diode behavior; open-circuit voltage; p-doped region; parallel resistance; reverse saturation current; single-walled carbon nanotubes; Carbon nanotubes; Doping; Logic gates; Photonic band gap; Physics; Schottky diodes; Bandgap renormalization (BGR); carbon nanotube (CNT); minority carrier lifetime; p-n junction; photodiode; schottky diode;

fLanguage

English

Journal_Title

Nanotechnology, IEEE Transactions on

Publisher

ieee

ISSN

1536-125X

Type

jour

DOI

10.1109/TNANO.2013.2287124

Filename

6648469