Heterostructure from PbS Quantum Dot and Carbon Nanotube Inks for High‐Efficiency Near‐Infrared Light‐Emitting Field‐Effect Transistors

Light-emitting field-effect transistors (LEFETs) are emerging optoelectronic devices able to display simultaneously electrical switching as and electroluminescence emission light emitting diodes. Lead chalcogenide colloidal quantum dots (CQDs) allow achieving in a very broad spectral range, covering the near-infrared (NIR) short-wavelength infrared (SWIR) regions, which cannot be reached with other solution-processable materials. Therefore, use of lead CQDs active layer LEFETs opens possibility for narrow switchable sources NIR SWIR range. The recently reported, first fully solid-state (PbS) CQD based LEFET shows an (EL) efficiency 1.3 × 10−5 at room temperature about 1% below 100 K. To overcome limits previous report, material comprising two sequentially deposited layers is designed, PbS displaying n-type transport second polymer-wrapped semiconducting carbon nanotubes p-type dominated transport. With this double system, well-balanced ambipolar transport, charge carrier mobility 0.2 cm2 V−1 s−1 both electrons holes, EL external reaching 1.2 10−4 obtained.