Title :
Comparative Investigation of the Effect of Oxygen Adsorbate and Electrode Work Function on Carbon-Nanotube Field-Effect Transistors
Author :
McClain, Devon ; Thomas, Nicole ; Youkey, Steven ; Schaller, Rebecca ; Jiao, Jun ; O´Brien, Kevin P.
Author_Institution :
Dept. of Phys., Portland State Univ., Portland, OR, USA
Abstract :
The effect of electrode work function (WF) on the device resistance of carbon-nanotube field-effect transistors (CNT-FETs) is less significant than that of device surface chemistry, specifically interactions with molecular oxygen adsorbate. Experimental results are based on over 130 individual devices with electrode WFs varying from 4.17 to 5.21 eV that were tested under standard-atmosphere, ultrahigh-vacuum, and pure-oxygen environments. Oxygen decreased device resistance by an average of 56% and altered majority charge carriers regardless of electrode metal. Variations in CNT-FET performance based on electrode material appeared more closely associated with crystallization and oxidation states than WF.
Keywords :
carbon nanotubes; crystallisation; field effect transistors; nanotube devices; oxidation; oxygen; work function; C; CNT-FET; O; carbon-nanotube field-effect transistors; charge carriers; crystallization states; device resistance; electrode work function; electron volt energy 4.17 eV to 5.21 eV; oxidation states; oxygen adsorbate effect; surface chemistry; Carbon compounds; electrodes; field-effect transistors (FETs); work function (WF);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2009.2037345
