Spatially Resolved Electrostatic Potential and Photocurrent Generation in Carbon Nanotube Array Devices
| Autor: | Mathias Steiner, Phaedon Avouris, Ralph Krupke, Alexander A. Green, R. S. Sundaram, Mark C. Hersam, Michael Engel |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Photocurrent
Materials science Light Nanotubes Carbon business.industry Photovoltaic system General Engineering Nanophotonics General Physics and Astronomy Equipment Design Carbon nanotube law.invention Equipment Failure Analysis Electromagnetic Fields Semiconductors Nanoelectronics law Materials Testing Microscopy Optoelectronics General Materials Science Charge carrier business Image resolution |
| Zdroj: | ACS Nano. 6:7303-7310 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/nn302416e |
| Popis: | We have used laser-excited photocurrent microscopy to map the internal electrostatic potential profile of semiconducting single-walled carbon nanotube (S-SWCNT) array devices with a spatial resolution of 250 nm. The measurements of S-SWCNTs on optically transparent samples provide new insights into the physical principles of device operation and reveal performance-limiting local heterogeneities in the electrostatic potential profile not observable with other imaging techniques. The experiments deliver photocurrent images from the underside of the S-SWCNT-metal contacts and thus enable the direct measurement of the charge carrier transfer lengths at the palladium-S-SWCNT and aluminum-S-SWCNT interfaces. We use the experimental results to formulate design rules for optimized layouts of S-SWCNT-based photovoltaic devices. Furthermore, we demonstrate the external control of the electrostatic potential profile in S-SWCNT array devices equipped with local metal gates. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|