Near-Infrared Emitting Fibers: Stable Jet Electrospinning Flat PbSe Quantum Dots into Poly(methyl methacrylate).

Flat colloidal PbSe QDs (fQDs) represent an innovative class of 2D near-infrared (NIR) photoluminescent QDs, which combine extreme thickness with additional lateral confinement. PbSe fQDs exhibit efficient NIR photoluminescence (860-1550 nm) that is adjustable to the low-loss transmission windows of (optical) fibers and makes them highly promising nanoemitters for fiber-based applications. Here, we demonstrate the incorporation of PbSe fQDs into easy-to-handle functional and stable jet electrospun poly(methyl methacrylate) (PMMA) fibers. Within these electrospun nanocomposites, we find perpendicularly alignedstacks of PbSe fQDs, which give rise to a narrowed and bathochromically shifted photoluminescence (e.g., at 1073 nm, with a quantum yield of 5%) that is caused by an energy transfer into the smallest band gap tail of the PbSe fQD thickness distribution. Embedding PbSe fQDs into solid-state nanocomposite fibers represents an important step forward for implementing near-infrared (NIR)-emitting 2D PbX nanocrystals in fiber optics.