Charge transfer dynamics in CsPbBr₃ perovskite quantum dots–anthraquinone/fullerene (C₆₀) hybrids

Abstract

An advantage of colloidal quantum dots, particularly perovskite quantum dots (PQDs), as photoactive components is that they easily form complexes with functional organic molecules, which results in hybrids with enriched photophysical properties.

Perovskite Nano‐Heterojunctions: Synthesis, Structures, Properties, Challenges, and Prospects

“…[153,154] However, conjugated functional molecules may have proper HOMO-LUMO levels favorable for charge/energy transfer with perovskite NCs, forming a type of special nano-heterojunction. Some typical examples are shown in Figure 20, such as perovskite NCs modified by benzoquinone (BQ) and phenothiazine (PTZ), [155,156] functionalized cinnamic acid (R-CAH), [157] 1-naphthalene carboxylic acid (NCA), [158] 1-pyrenecarboxylic acid (PCA), [159] 1-ampinopyrene (AMP), [160] anthraquinone-2-carboxylic acid (AQ), [161,162] 5-tetracene carboxylic acid (TCA), [163] tetrathiophene ligands 4Tm and 4TCNm, [164] N3 dye, [165] and fullerene (C60). [162] The interlayer ligands of 2D layered perovskite also can be functionalized, e.g., chiral ligands would introduce chiral photonic properties.…”

Nanoscale Photoinduced Charge Transfer with Individual Quantum Dots: Tunability through Synthesis, Interface Design, and Interaction with Charge Traps

“…12,38−44 In doing so, hybrid QD-based donor–acceptor systems can be fabricated by band-gap engineering of the QD and of the QD–acceptor interface. 45−57 Band-gap engineering of QDs allows to obtain optimal band alignment with the acceptor component in order to promote efficient photoinduced charge transfer. 39 Engineering of the donor–acceptor interface can further improve the efficiency of this process or it can allow rate tunability.…”

Multiphoton Excitation of CsPbBr3 Perovskite Quantum Dots (PQDs): How Many Electrons Can One PQD Donate to Multiple Molecular Acceptors?

“…The extended functionalities of PQDs have been achieved by combining them with organic molecular electron donors and acceptors, preferably adsorbed on the surface of the PQDs to form ground-state complexes, and gaining photoinduced charge separation between PQDs and organic molecules. 31−36 To the best of our knowledge the possibility of charge transfer from PQD multiexcitonic states has not been demonstrated yet.…”

“…In our previous report, we showed that electron transfer from CsPbBr 3 PQD to AQ is thermodynamically favorable because the conduction band (CB) energy of PQD (−3.0 eV relative to the vacuum level) is higher than the lowest unoccupied molecular orbital (LUMO) of AQ (−3.5 eV relative to vacuum level) and observed electron transfer with a time constant of 30 ps. 36 Herein, we report on the study of MESs in CsPbBr 3 PQDs and multiple electron transfer from one multiexcited PQD to multiple electron acceptors, AQs in PQD–AQ hybrids, using ultrafast transient absorption (TA) spectroscopy. We show that as many as 14 excitons can be generated in one PQD at the highest excitation density used in this study and in the presence of AQ, 5 excitons are dissociated by electron transfer with the first electron-transfer reactions as fast as 1 ps.…”

“…In PQD–AQ hybrids, the emission and lifetime quenching of PQD are due to the electron transfer from PQD to AQ, which was already reported in our recent article. 36…”