Prechtel, Leonhard and Song, Li and Schuh, Dieter and Ajayan, Pulickel and Wegscheider, Werner and Holleitner, Alexander W. (2012) Time-resolved ultrafast photocurrents and terahertz generation in freely suspended graphene. NATURE COMMUNICATIONS, 3: 646. ISSN 2041-1723,
Full text not available from this repository. (Request a copy)Abstract
Graphene, a two-dimensional layer of carbon atoms, is a promising building block for a wide range of optoelectronic devices owing to its extraordinary electrical and optical properties, including the ability to absorb similar to 2% of incident light over a broad wavelength range. While the RC-limited bandwidth of graphene-based photodetectors can be estimated to be as large as 640 GHz, conventional electronic measurement techniques lack for analysing photocurrents at such frequencies. Here we report on time-resolved picosecond photocurrents in freely suspended graphene contacted by metal electrodes. At the graphene-metal interface, we demonstrate that built-in electric fields give rise to a photocurrent with a full-width-half-maximum of similar to 4 ps and that a photothermoelectric effect generates a current with a decay time of similar to 130 ps. Furthermore, we show that, in optically pumped graphene, electromagnetic radiation up to 1 THz is generated. Our results may prove essential to build graphene-based ultrafast photodetectors, photovoltaic cells and terahertz sources.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ELECTRICAL PULSE GENERATION; TRANSMISSION-LINES; EPITAXIAL GRAPHENE; DYNAMICS; SPECTROSCOPY; MICROSCOPY; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 25 May 2020 09:06 |
| Last Modified: | 25 May 2020 09:06 |
| URI: | https://pred.uni-regensburg.de/id/eprint/19555 |
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