Microcavity-Controlled Chirality-Sorted Carbon Nanotube Film Infrared Light Emitters

Applied as on-chip infrared light sources for future nanophotonic circuits and information optoelectronics, light emitters should show a narrow spectral width, strong emission, low onset voltage, and better tunability of light output to an external drive. Here, by utilizing small-diameter (d < 1 nm) chirality-sorted (8,3) and (8,4) carbon nanotube (CNT) films and their charged exciton (trions) electroluminescence (EL), we achieve performance improvements via channel length (L-ch) scaling. With a short Lch, the devices can show better emission, and the external EL efficiency (eta(gL)) in free space can reach similar to 6 x 10(4) (that is obtained at a current of similar to 58 mA and a voltage of similar to 46 V from the 0.5-mu m-channel device, and the corresponding current density is similar to 17003000 A cm(2)). The strong emission at smaller bias gives CNT-based emitters a wider optoelectronic compatibility with other nanomaterial systems. Furthermore, by an integration of the emitter with a lambda/2 optical cavity, cavity-controlled well-defined light output can be achieved, with narrow spectral widths at selectable emission windows (e.g., similar to 28 meV at a wavelength of 1180 nm). The results show possible applications of chirality-sorted CNT film light emitters for further on-chip nanophotonic systems.