Size-Dependent Non-FRET Photoluminescence Quenching in Nanocomposites Based on Semiconductor Quantum Dots CdSe/ZnS and Functionalized Porphyrin Ligands

Table 1

Structural and spectral-kinetic properties of CdSe and CdSe/ZnS QDs as well as FRET and PL quenching parameters for “QD- porphyrin H₂P(m-Pyr)₄” nanocomposites in toluene at 295 K.

Quantum dots (Evident Technologies Nomenclature)	𝜆max ^a, nm	CdSe core diameter^b d, nm	ZnS ML number n^c	QD diameter nm	QD PL decay^d⟨𝜏0⟩ ns	Stern-Volmer constant^e⟨𝐾SV(𝑥)⟩	QD PL total quenching rate constant^f𝑘𝑞, ns^−1	FRET “QD-porphyrin” rate constant^g𝑘FRET, ns^‒1
Snapdragon Orange	568	3.5	—	3.5	20 ± 5	0.80 ± 0.12	0.041 ± 0.016	0.0015 ± 0.0008
Lake Placid Blue	476	2.1	2	4.3	35 ± 6	0.65 ± 0.10	0.018 ± 0.010	0.0013 ± 0.0003
Hops Yellow	548	3.0	2	5.2	25 ± 6	0.115 ± 0.015	0.0057 ± 0.0023	0.0007 ± 0.0002
Fort Orange	587	4.1	2	6.3	20 ± 5	0.055±0.007	0.0027 ± 0.0016	<0.0001
Maple Red	613	5.2	2	7.3	13 ± 4	0.020 ± 0.003	0.0015 ± 0.0009	<0.0001

^aMaximum of the first excitonic band in absorption (𝜆_max).
^bFound from the first exciton absorption peak on the basis of well-proven experimental dependences between the position of the first excitonic maximum in absorption and the nanoparticle diameter [60–62].
^cNumber of ZnS monolayers were known from the producer (Evident Technologies), thickness of ZnS shell at 𝑛=2 ML is 𝑙=10 Å.
^dMean PL decay was calculated as ⟨𝜏⟩=∑_𝑖𝐴_𝑖𝜏²_𝑖/∑_𝑖𝐴_𝑖𝜏_𝑖.
^eEstimated from experimental Stern-Folmer plots (2).
^fCalculated from (3).
^gFound from experimental data presented in Figure 6(b).