Two-step light conversion with quantum dots inside non-linear crystals

Dmytro Vorontsov; Galyna Okrepka; Yuriy Khalavka; Jan Valenta

doi:10.1063/5.0022785

Two-step light conversion with quantum dots inside non-linear crystals

J Chem Phys. 2020 Sep 28;153(12):121105. doi: 10.1063/5.0022785.

Authors

Dmytro Vorontsov¹, Galyna Okrepka², Yuriy Khalavka³, Jan Valenta¹

Affiliations

¹ Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu, 3, 121 16 Prague 2, Czech Republic.
² Department of Medical and Pharmaceutical Chemistry, Bukovinian State Medical University, Teatral'na Square, 2, Chernivtsi 58012, Ukraine.
³ Department of General Chemistry and Chemical Materials Science, Institute of Biology, Chemistry and Bioresources, Yuriy Fed'kovych Chernivtsi National University, Kotsyubyns'kogo St., 2, Chernivtsi 58002, Ukraine.

PMID: 33003710
DOI: 10.1063/5.0022785

Abstract

Up-conversion of infrared (IR) to visible light is demonstrated via an unconventional two-step process combining second harmonic generation with photoluminescence. This is achieved in a composite material formed by single crystals of KH₂PO₄ (KDP), in which CdTe/CdS quantum dots (QDs) are embedded during a crystal growth. The second harmonic generation from the IR laser frequency in KDP takes place, and then, generated light is absorbed by QDs and luminescence is emitted. Compared to the most common up-converting materials based on lanthanide ions, our novel composites use only abundant elements and have several other properties with application potential: the excitation and emission can cover a broader spectral range, and the response is much faster (ns compared to ms) and is strongly dependent on the direction of the incident beam.