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Karthik Ramasamy1 Nikolay Makarov1 Aaron Jackson1 Matt Bergren1 Hunter McDaniel1

1, UbiQD, Inc, Los Alamos, New Mexico, United States

The rapidly growing near-infrared (NIR) spectrum-based industries like luminescent solar concentrating (LSC) windows, deep tissue bio-imaging, security inks, NIR sensors, and medical diagnostics demand high-performance, stable, tunable, and non-toxic NIR materials. At present, the NIR fluorophores available in the market such as organic dyes, fluorescent diamonds, fluorescent proteins severely lack wavelength tunability, have low quantum yield (QY), poor photostability, small extinction coefficient, and/or insignificant Stokes shifts. On the other hand, NIR emitting CdTe, CdHgTe or PbS/Se quantum dots have low QY and they are composed of toxic and RoHS prohibited elements such as Cd, Hg or Pb which hamper their use in practical applications. At UbiQD, we address these problems with low-toxic CuInSexS2-x/ZnS QDs at a much lower cost than alternatives. Importantly, CuInSeS/ZnS QDs have a tunable emission covering from visible (550 nm to 650 nm) to NIR (650 nm to 1300 nm) spectral regions with over 90% QYs for most of the region coupled with good stability, large absorption cross-sections, and large Stokes shifts. As an example this technology’s potential, we recently demonstrated a record solar window conversion efficiency of 2.9% at 60 % transmittance using CuInSeS/ZnS NIR QDs. This presentation will discuss our development of NIR-emitting QDs together with challenges and progress of various emerging applications of NIR QDs.

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