Luminescent films employing quantum dot-cellulose nanocrystal hybrid nanomaterials

Colloidal quantum dot (QD) materials are promising candidates for luminescent solar concentrator (LSC) technology thanks to their broadband absorption above semiconductor bandgap and tunable Stokes-shift for minimizing the light reabsorption. Previously reported QDs in LSC contain non-polar organic ligands that can be easily incorporated into common host matrix/waveguide materials – polyacrylates or polycarbonates, however, these organic ligands on QD surfaces introduce problems when some new matrix materials are employed. For example, cellulose nanocrystal (CNC), a wood-derived eco-friendly material, has the potential for LSC, but no solvents are available to dissolve both QD and CNC simultaneously. Here we report high-quality luminescent films employing QD-CNC hybrid materials. Such films are produced from stable QD-CNC suspension by applying solution-phase exchange to replace non-polar organic ligands on QDs to the metal halide complex, as well as performing acetylation on CNC surfaces. The fabricated QD-CNC hybrid film keeps similar photoluminescence quantum yield and lifetime compared to as-synthesized QDs in non-polar organic solvents. The developed method in this work has the potential to be widely used to mix QD with other materials having polar functional groups.