Direct triplet sensitization of oligothiophene by quantum dots

Abstract

Triplet energy transfer from quantum dots takes advantage of small energy loss during intersystem crossing.

Prospects of Coupled Organic–Inorganic Nanostructures for Charge and Energy Transfer Applications

“…Organic ligands and p-systems PbSe Rubrene [25] Pentacene [26] PbS 5,11-Bis(triethylsilylethynyl)anthradithiophene [27] Rubrene (acceptor) [28] , 5-carboxylic acid tetracene (transmitter) [29,30] Tetracene [31] 2-Carboxylic acid TIPS-tetracene [32] 2-Benzoic acid TIPS-pentacene [33] Zinc b-tetraaminophthalocyanine [13] Poly[sodium 2-(2-ethynyl-4-methoxyphenoxy)acetate] [34] CdSe Anthracene derivatives [35] Pentacene derivatives [36] Oligothiophenecarboxylic acid [37] 1-Perylenecarboxylic acid (PCA) [38] 2-Chloro-9,10-bisphenylethynylanthracene (acceptor), PCA (transmitter) [39] Diphenylanthracene (acceptor), bis(pyridine) anthracene (transmitter) [40] Diphenylanthracene (acceptor), 9-anthracene carboxylic acid (transmitter) [41,42] Zinc b-tetraaminophthalocyanine [43] CsPbBr 3 PCA [44] 1-Naphthalenecarboxylic acid [45] Diphenylanthracene (acceptor), aminodiphenylanthracene (transmitter) [46] Two-dimensional MoS 2 Methyl orange, rhodamine 6G, methylene blue [47] Zinc phthalocyanine [48] Pentacene [49] To prevent surface reconstruction, the manifestation of defects and a deterioration of the electronic properties discussed above, the surfaces of QDs need to be passivated by some matrix. [52] In epitaxially grown QDs, this is achieved by embedding the QDs in another inorganic material with matching lattice constant.…”

“…Commonly used small molecule organic dyes are polyacenes, for example, rubrene [25] and anthracene derivatives, [39] phthalocyanines [13] and oligothiophenes (see Table 1). [37] …”

“…Furthermore, triplet harvesting and fast triplet transfer is often the rate‐limiting step in multiexciton generation by singlet fission (see section 4.1), which bears the potential to exceed the Shockley‐Queisser efficiency limit for solar cells [128] . Material combinations tested in this regard so far are summarized in Table 1 [25, 27, 35–38, 44, 45] . A crucial bottleneck for triplet transfer is the competing recombination of the triplet exciton to the NC ground state via intersystem crossing, which often occurs on a nanosecond timescale, that is, much faster than in organic π‐systems.…”

Perspektiven gekoppelter organisch‐anorganischer Nanostrukturen für Ladungs‐ und Energietransferanwendungen

“…Häufig verwendete niedermolekulare organische Farbstoffe sind Polyacene, zum Beispiel Rubren‐ [25] und Anthracenderivate, [39] Phthalocyanine [13] und Oligothiophene (siehe Tabelle 1). [37] …”

“…Darüber hinaus ist die Triplettgewinnung und der schnelle Triplett‐Transfer häufig der geschwindigkeitsbestimmende Schritt bei der Mehrfach‐Exzitonenerzeugung durch Singulettspaltung (siehe Abschnitt 4.1), mit der möglicherweise die Shockley‐Queisser‐Wirkungsgradgrenze für Solarzellen überschritten werden kann [128] . Die bisher diesbezüglich getesteten Materialkombinationen sind in Tabelle 1 zusammengefasst [25, 27, 35–38, 44, 45] . Ein kritischer Engpass für den Triplett‐Transfer ist die konkurrierende Rekombination des Triplett‐Exzitons zum NK‐Grundzustand durch Intersystem‐Crossing, das oftmals innerhalb von Nanosekunden erfolgt, d. h. viel schneller als in organischen π‐Systemen.…”