Spin-enabled photochemistry using nanocrystal-molecule hybrids

•The short spin lifetimes of CsPbBr3 nanocrystals are useful for photochemistry•Nanocrystals flip the photoexcited dyes to produce molecular triplets•The triplets applied photon upconversion and singlet-oxygen generation Recent years have seen growing interest in properties solution-processed semiconductor materials made by chemists. These promise low-cost, scalable, flexible implementation spintronic quantum information technologies but still plagued their very (picoseconds) lifetimes. Here, we present that these can instead find immediate applications photochemistry largely relies on spin-relaxed triplet states. We demonstrate spin-enabled using surface-anchored with rhodamine B molecules time-resolved spectroscopy. In this system, excitation either nanocrystal or molecule induced charge separation, a rapid spin-flip carrier inside enabled high-yield formation through recombination, which triplet-fusion upconversion, generation, many more photochemical applications. 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After attachment, NC-RhB contains contributions both Importantly, responses each other, hence, harvest most photons below 600 2A). advantage design will illustrated later. An approximate alignment obtained basis positions NCs49Luo redox potentials RhB,56Boulesbaa Issac Stockwell Guo CdS dot/rhodamine b interface.J. 2007; 129: 15132-15133Crossref (221) plotted 2B. component, confirmed photoluminescence (PL) measurements. 2C, PL selective 540 displays near-unity quenching consistent (1RhB∗) HOMO; 1B). Similarly, 330 (dominated absorption) strongly quenched 2D). latter case, possibilities Förster Dexter mechanisms57DuBose J.T. Kamat P.V. Directing perovskite–chromophore assemblies.J. 19214-19223Crossref (26) cannot excluded. Nevertheless, 1RhB∗, triggering pathways same 2C. Time-resolved measured single-photon counting indicates instrumental resolution (∼1 ns); see S2. femtosecond transient (TA) investigate processes; setups. TA experiment prior study50Luo (see S3 related data current sample), here, RhB. measurements performed under deaerated conditions, pump powers lowered small-signal regime multiexciton negligible. 3A pseudocolor excitation. beginning, ground-state bleach (GSB; ∼560 nm) stimulated (SE; 570–650 features dominate spectra. SE decays picoseconds, accompanied strong (490 two nearby (∼475 500 nm). observed S4A). On 2B, decay NC-related attributed 1RhB∗