Electrical pumping and tuning of exciton-polaritons in carbon nanotube microcavities

Abstract

Exciton-polaritons are hybrid light-matter particles that form upon strong coupling of an excitonic transition to a cavity mode. As bosons, polaritons can form condensates with coherent laser-like emission. For organic materials, optically pumped condensation was achieved at room temperature but electrically pumped condensation remains elusive due to insufficient polariton densities. Here we combine the outstanding optical and electronic properties of purified, solution-processed semiconducting (6,5) single-walled carbon nanotubes (SWCNTs) in a microcavity-integrated light-emitting field-effect transistor to realize efficient electrical pumping of exciton-polaritons at room temperature with high current densities (>10 kA cm) and tunability in the near-infrared (1,060 nm to 1,530 nm). We demonstrate thermalization of SWCNT polaritons, exciton-polariton pumping rates ∼10 times higher than in current organic polariton devices, direct control over the coupling strength (Rabi splitting) via the applied gate voltage, and a tenfold enhancement of polaritonic over excitonic emission. This powerful material-device combination paves the way to carbon-based polariton emitters and possibly lasers.

Near‐Infrared (NIR) Organic Light‐Emitting Diodes (OLEDs): Challenges and Opportunities

“…Interestingly, organic light-emitting transistors (OLETs) provide a wholly different device architecture that has shown intriguing performance figures for visible emitters [121] and that offers specific opportunities for NIR emitters because of the already mentioned modest need of electrodes work function engineering, which allows fabrication of OLETs with the same electrodes material for injection of both electrons and holes. [104,122] Examining next the materials perspectives we note that significant progress has already been achieved by implementation of several chemical design strategies, as reviewed above, and with some remarkable results in terms of efficiency for all the three main classes of NIR-OLEDs: phosphorescent, triplet-leveraging fluorescent (TADF -TTA), and purely fluorescent, possibly hinting that the progress needed for any commercialisation might by now be more related to device lifetime and durability than to EQEs.…”

Manipulating molecules with strong coupling: harvesting triplet excitons in organic exciton microcavities

“…Because of progress in electrically injected polariton devices [15][16][17][18] , however, it is important to consider in more detail the fate of these states and how they interact with polaritons. Similarly to electrical injection, a very large reservoir of triplets can be generated by photoexcitation in some materials.…”

Semiconducting Single‐Walled Carbon Nanotubes or Very Rigid Conjugated Polymers: A Comparison

“…[277] As shown in Sections 3.1 and 4.1 the absorption and emission of semiconducting nanotubes is tunable by doping (ground-state bleaching, trion absorption and emission). [277] As shown in Sections 3.1 and 4.1 the absorption and emission of semiconducting nanotubes is tunable by doping (ground-state bleaching, trion absorption and emission).…”