Characterization of gold contacts in GaAs-based molecular devices: Relating structure to electrical properties

Author

• Patrick D. Carpenter, School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue UniversityFollow
• Saurabh Lodha, School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University
• David B. Janes, Purdue UniversityFollow
• Amy V. Walker, Washington University

Abstract

Au/octadecanethiol/GaAs devices were prepared using different metallization conditions: direct deposition at 77 K and 300 K samples, and indirect deposition (Ar backfilling). Time-of-flight secondary ion mass spectrometry data indicate that similar to 4x and similar to 2x more gold penetrates through the SAM after direct deposition at 300 K and 77 K, respectively, than under Ar backfill conditions. However, these devices have significantly different conductances: Ar-backfill and 77 K samples have similar to 200x and similar to 70x, respectively, larger conductances than 300 K devices. An electrostatic model has been developed to explain the very large conductance changes due to small differences in device structure.

Keywords

SELF-ASSEMBLED MONOLAYERS; BARE SEMICONDUCTOR SURFACES; ELECTRONIC TRANSPORT; ALKANETHIOLATE MONOLAYERS; PENETRATION PATHWAYS; CHARGE-TRANSPORT; BOND INSERTION; CONDUCTANCE; GAAS(001); JUNCTIONS

Date of this Version

4-20-2009

Recommended Citation

Carpenter, Patrick D.; Lodha, Saurabh; Janes, David B.; and Walker, Amy V., "Characterization of gold contacts in GaAs-based molecular devices: Relating structure to electrical properties" (2009). Birck and NCN Publications. Paper 379.
https://docs.lib.purdue.edu/nanopub/379