Cavity-controlled, electrically-induced infrared emission from a single single-wall carbon nanotube (SWCT)

Abstract

We have integrated an electrically excited light emitter using a single SWCT with a planar photonic O/2-cavity. The spectral width of cavity-controlled emission is 7 times narrower than the free-space emission from the same SWCT.2008 Optical Society of America OCSI codes: (130.3120) IntroductionSingle-wall carbon nanotube (SWCT) devices are extensively studied by physicists and engineers as promising candidates for electronics in the post CMOS era [1][2]. Recently, SWCTs have attracted significant attention from the photonics community due to their excellent optical properties and potential applications in optical communications, optical interconnects, and, in particular, nanophotonics. Unlike other group IV materials such as silicon and germanium, semiconducting SWCTs have a direct and diameter-tunable bandgap. Light emission from single SWCT-based field effect transistor (FET) has already been demonstrated [3]. Highly efficient, tunable and truly nanometer-scale (diameters of 0.5 to 2nm) light emitters can possibly be realized based on individual semiconducting nanotubes. Theoretical work also predicts a large Franz-Keldysh effect in this quasi onedimensional (1-D) system [4] and hence high performance electro-optic modulators may be constructed using SWCTs. Excellent photo-detection abilities have also been demonstrated using SWCTs [5]. All previous demonstrations and theoretical investigations suggest potential applications of SWCTs in many advanced photonic applications.For the first time, we demonstrate here the monolithic integration of a light emitting FET based on an individual SWCT (with a diameter of ~ 1.6nm) with a planar photonic O/2-cavity. Cavity-controlled infrared emission originating from radiative electron-hole recombination in an individual SWCT is experimentally observed complementing studies of optically excited Raman scattering of cavity-confined SWCTs [6]. The resulting emission spectrum is narrowed by a factor of 7 with respect to the emission spectrum measured from the same SWCT in free (non-confined) space and is essentially determined by the quality (Q) factor of the photonic cavity. The maximum Purcell enhancement [7] factor for the SWCT emission is estimated to be around 4.5. This demonstration may have important implications on the development of SWCT-based devices for advanced photonic applications.