Photocurrent Quantum Yield in Suspended Carbon Nanotube p-n Junctions
| Autor: | Daniel R. McCulley, Ethan D. Minot, Lee Aspitarte |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Exciton Schottky barrier Quantum yield Bioengineering 02 engineering and technology Carbon nanotube 01 natural sciences law.invention Condensed Matter::Materials Science law 0103 physical sciences General Materials Science 010306 general physics Absorption (electromagnetic radiation) Photocurrent business.industry Mechanical Engineering General Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics Multiple exciton generation Optoelectronics 0210 nano-technology business Order of magnitude |
| Zdroj: | Nano letters. 16(9) |
| ISSN: | 1530-6992 |
| Popis: | We study photocurrent generation in individual suspended carbon nanotube p–n junctions using spectrally resolved scanning photocurrent microscopy. Spatial maps of the photocurrent allow us to determine the length of the p–n junction intrinsic region, as well as the role of the n-type Schottky barrier. We show that reverse-bias operation eliminates complications caused by the n-type Schottky barrier and increases the length of the intrinsic region. The absorption cross-section of the CNT is calculated using an empirically verified model, and the effect of substrate reflection is determined using FDTD simulations. We find that the room temperature photocurrent quantum yield is approximately 30% when exciting the carbon nanotube at the S44 and S55 excitonic transitions. The quantum yield value is an order of magnitude larger than previous estimates. |
| Databáze: | OpenAIRE |
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