TY - JOUR
T1 - Triplet transfer from PbS quantum dots to tetracene ligands
T2 - is faster always better?
AU - Gray, Victor
AU - Drake, William
AU - Allardice, Jesse R.
AU - Zhang, Zhilong
AU - Xiao, James
AU - Congrave, Daniel G.
AU - Royakkers, Jeroen
AU - Zeng, Weixuan
AU - Dowland, Simon
AU - Greenham, Neil C.
AU - Bronstein, Hugo
AU - Anthony, John E.
AU - Rao, Akshay
N1 - Publisher Copyright:
© 2022 The Royal Society of Chemistry.
PY - 2022/10/11
Y1 - 2022/10/11
N2 - Quantum dot-organic semiconductor hybrid materials are gaining increasing attention as spin mixers for applications ranging from solar harvesting to spin memories. Triplet energy transfer between the inorganic quantum dot (QD) and organic semiconductor is a key step to understand in order to develop these applications. Here we report on the triplet energy transfer from PbS QDs to four energetically and structurally similar tetracene ligands. Even with similar ligands we find that the triplet energy transfer dynamics can vary significantly. For TIPS-tetracene derivatives with carboxylic acid, acetic acid and methanethiol anchoring groups on the short pro-cata side we find that triplet transfer occurs through a stepwise process, mediated via a surface state, whereas for monosubstituted TIPS-tetracene derivative 5-(4-benzoic acid)-12-triisopropylsilylethynyl tetracene (BAT) triplet transfer occurs directly, albeit slower, via a Dexter exchange mechanism. Even though triplet transfer is slower with BAT the overall yield is greater, as determined from upconverted emission using rubrene emitters. This work highlights that the surface-mediated transfer mechanism is plagued with parasitic loss pathways and that materials with direct Dexter-like triplet transfer are preferred for high-efficiency applications.
AB - Quantum dot-organic semiconductor hybrid materials are gaining increasing attention as spin mixers for applications ranging from solar harvesting to spin memories. Triplet energy transfer between the inorganic quantum dot (QD) and organic semiconductor is a key step to understand in order to develop these applications. Here we report on the triplet energy transfer from PbS QDs to four energetically and structurally similar tetracene ligands. Even with similar ligands we find that the triplet energy transfer dynamics can vary significantly. For TIPS-tetracene derivatives with carboxylic acid, acetic acid and methanethiol anchoring groups on the short pro-cata side we find that triplet transfer occurs through a stepwise process, mediated via a surface state, whereas for monosubstituted TIPS-tetracene derivative 5-(4-benzoic acid)-12-triisopropylsilylethynyl tetracene (BAT) triplet transfer occurs directly, albeit slower, via a Dexter exchange mechanism. Even though triplet transfer is slower with BAT the overall yield is greater, as determined from upconverted emission using rubrene emitters. This work highlights that the surface-mediated transfer mechanism is plagued with parasitic loss pathways and that materials with direct Dexter-like triplet transfer are preferred for high-efficiency applications.
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U2 - 10.1039/d2tc03470k
DO - 10.1039/d2tc03470k
M3 - Article
AN - SCOPUS:85141325816
SN - 2050-7526
VL - 10
SP - 16321
EP - 16329
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
IS - 43
ER -