Triplet energy transfer from quantum dots increases Ln(iii) photoluminescence, enabling excitation at visible wavelengths

Tingting Huang; Sheng He; Anji Ni; Tianquan Lian; Ming Lee Tang

doi:10.1039/d3sc05408j

Triplet energy transfer from quantum dots increases Ln(iii) photoluminescence, enabling excitation at visible wavelengths

Chem Sci. 2024 Feb 27;15(12):4556-4563. doi: 10.1039/d3sc05408j. eCollection 2024 Mar 20.

Authors

Tingting Huang¹, Sheng He², Anji Ni², Tianquan Lian², Ming Lee Tang¹

Affiliations

¹ Department of Chemistry, University of Utah Salt Lake City UT 84112 USA minglee.tang@utah.edu.
² Department of Chemistry, Emory University 1515 Dickey Drive Northeast Atlanta Georgia 30322 USA tlian@emory.edu.

Abstract

Europium(iii) complexes are promising for bioimaging because of their long-lived, narrow emission. The photoluminescence (PL) from europium(iii) complexes is usually low. Thus, the effective utilization of low-energy light >400 nm and enhancement of PL are long-standing goals. Here, we show for the first time that 1-naphthoic acid triplet transmitter ligands bound to CdS quantum dots (QDs) and europium(iii) complexes create an energy transfer cascade that takes advantage of the strong QD absorption. This is confirmed by transient absorption spectroscopy, which shows hole mediated triplet energy transfer from QDs to 1-NCA, followed by triplet transfer from 1-NCA to europium(iii) complexes with an efficiency of 65.9 ± 7.7%. Smaller CdS QDs with a larger driving force lead to higher triplet transfer efficiency, with Eu(iii) PL intensity enhanced up to 21.4 times, the highest value ever reported. This hybrid QD system introduces an innovative approach to enhance the brightness of europium complexes.