Highly Soluble CsPbBr3 Perovskite Quantum Dots for Solution-Processed Light-Emission Devices

• We report on the synthesis of CsPbBr3 perovskite quantum dots (PeQDs) with a high solubility of 75 g/L in toluene and a good film-forming property, as enabled by a dense layer of didodecyldimethylammonium bromide and octanoic acid surface ligands. The crystalline and monodisperse PeQDs feature a cubic-like shape, with an edge length of 10.1 nm, and a high photoluminescence quantum yield of greater than 90% in toluene solution and 36% as a thin film. We find that the PeQDs are n-type doped following the synthesis but also that they can be p-type and additionally n-type doped by in situ electrochemistry. These combined properties render the PeQDs interesting for the emitter in solution-processed light-emitting electrochemical cells (LECs), and we report a PeQD-LEC with air-stabile electrodes that emits with a narrow emission spectrum (λpeak = 514 nm, full width at half-maximum = 24 nm) and a luminance of 250 cd/m2 at 4 V and a luminance of 1090 cd/m2 at 6.8 V. To reach this performance, it was critical to include a thin solution-processed layer comprising p-type poly(vinyl carbazole) and a tetrahexylammonium tetrafluoroborate ionic liquid between the PeQD emission layer and the anode in order to compensate for the as-synthesized n-type doping of the PeQDs.

Ämnesord

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Nyckelord

perovskite quantum dots

surface ligands

high solubility

good film forming capacity

light-emitting electrochemical cell

ion migration

Materials Science

materialvetenskap

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