AVS 58th Annual International Symposium and Exhibition | |
Graphene and Related Materials Focus Topic | Tuesday Sessions |
Session GR+EM-TuM |
Session: | Graphene: Optical Properties, Optoelectonics and Photonics |
Presenter: | Andrea Ferrari, University of Cambridge, UK |
Correspondent: | Click to Email |
The richness of optical and electronic properties of graphene attracts enormous interest. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics, plasmonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, the absence of a bandgap can be beneficial, and the linear dispersion of the Dirac electrons enables ultra-wide-band tenability [1]. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Despite being a single atom thick, graphene can be optically visualized [2]. Its transmittance can be expressed in terms of the fine structure constant [3]. The linear dispersion of the Dirac electrons enables broadband applications. Saturable absorption is observed as a consequence of Pauli blocking [4,5]. Chemical and physical treatments enable luminescence [1,6]. Graphene-polymer composites prepared using wet chemistry [4-6] can be integrated in a fiber laser cavity, to generate ultrafast pulses, down to 100fs with up to 1 W average power, and enable broadband tunability [4,5]. Graphene-based mode-locked laser are a near term application for this extraordinary material, and can provide simple, low-cost, and convenient light sources for metrology, sensing, medicine and micromachining. Graphene is an ideal transparent flexible conductor. A flexible electrically switchable smart window will be reported, with over 230 contrast ratio, as well as an electro-tactile screen for mobile phone applications. The optoelectronic properties of graphene can be enhanced by combination with plasmonic nanostructures [7], for example in plasmonic-enhanced photovoltage generation [8]
1. F. Bonaccorso et al. Nature Photonics 4, 611 (2010)
2. C. Casiraghi et al. Nano Lett. 7, 2711 (2007).
3. R. R. Nair et al. Science 320, 1308 (2008).
4. T. Hasan, et al. Adv. Mat. 21,3874 (2009)
5. Z. Sun et al. ACS Nano 4, 803 (2010); Nano Research 3, 653 (2010)
6. T. Gokus et al. ACS nano 3, 3963 (2009)
7. F. Schedin, ACS Nano 4, 5617 (2010).
8. T.J. Echtermeyer et al, submitted (2011)