Exciton Transfer Research Articles

Examining the Impact of 3D Multi-Arm Small Molecules on PM6 : Y6 Blend Reveals the Key Requirements for Their Electronic Properties.

While the emergence of PM6 : Y6 active layer re-energized the organic photovoltaic community, excessive aggregation of Y6 molecules induced by their strong intermolecular interactions has limited the performance of PM6 : Y6-based organic solar cells (OSCs). Adding 3D multi-arm small-molecule acceptors is an effective strategy to inhibit such aggregation. However, to maximize OSC efficiency, these molecules should also contribute to the electronic processes. Here, by taking a benzotriazole-based 3D four-arm small molecule (i.e., SF-BTA1) as representative example, we combine molecular dynamics simulations and density functional theory calculations to examine the molecular-scale impact of 3D multi-arm small molecules on morphological characteristics (especially at the nanoscale) and electronic properties of PM6 : Y6 blends. By considering the intermolecular packing distances, density, and patterns among PM6, Y6, and SF-BTA1 components, exciton transfer rates from SF-BTA1 to Y6 or PM6, charge transfer rates from Y6 or PM6 to SF-BTA1, electron/hole transfer rates among adjacent Y6/PM6 pairs, and radiative and non-radiative recombination processes, we draw a comprehensive picture that describes how 3D multi-arm small molecules improve morphological and electronic properties of PM6 : Y6 blends and thus the OSC efficiency. Furthermore, successful rationalization of these aspects allows us to point out key requirements regarding the electronic properties of 3D multi-arm small molecules.

Real-Time CASSCF (Ehrenfest) Modeling of Electron Dynamics in Organic Semiconductors. Dynamics Reaction Paths Driven by Quantum Coherences. Application to a Radical Organic Semiconductor.

We present a strategy for the modeling of charge carrier dynamics in organic semiconductors using conventional quantum chemistry methods, including the analytic gradient for nuclear motion. The theoretical approach uses real-time CASSCF (Ehrenfest) all-electron dynamics coupled to classical nuclear dynamics for the special case of a small number (4-8) of molecular units. The objective is to obtain mechanistic/atomistic insight at the electronic structure level, relating to spin density dynamics, to the effect of crystal structure (e.g., slippage between spin/charge carriers), and to ferromagnetic and antiferromagnetic effects. The initial conditions for our simulations use the equilibrium structures of all the molecular units. At this geometry, a localized hole on one of the units corresponds to a coherent superposition of adiabatic states. We thus generate a dynamics reaction path driven by quantum coherences. Our aim is to inform experiment and to compare with parametrized theoretical models. The methodology is demonstrated for a perfectly π-stacked ethylene model (up to 8 eclipsed molecular units) for both hole transfer and localized exciton transfer. An application for hole transfer is presented for bisdithiazolyl (S,S) and bisdiselenazolyl (Se,Se) radicals for the special case of ferromagnetic coupling. For these examples, the embedded pyridine radical model organic chromophore (up to 6 eclipsed π-stacked molecular units) has been studied on its own as well as the target bisdithiazolyl (S,S) and bisdiselenazolyl (Se,Se) systems. A significant difference between these systems and the ethylene and pyridine stacks is that the (S,S) and (Se,Se) systems exhibit molecular slippage rather than being perfectly eclipsed. This slippage may result from crystal defects or intermolecular vibrations. For the model systems, the electron dynamics is dominated by the initial and final molecular units, irrespective of the length of the chain. The intervening units act as a "superexchange bridge". Our simulations reveal that, in the presence of slippage, charge migration cannot propagate across the entire system; instead, the coherence length is limited to 3 molecular units. The results also suggest that the mechanism of charge transport is different for bisdiselenazolyl (Se,Se) (superexchange-like A -[B]→ C) and bisdithiazolyl (S,S) (direct A → C). An analysis of the spin density suggests that, in the charge carrier dynamics, the additional charge carried by the Se versus S in the "scaffold" is small. Since we use a small number of molecular units, the coupled nuclear dynamics is seen to be complementary to the electron dynamics (i.e., creating a hole causes bond length contraction while filling a hole with an electron lengthens the bond). In all the cases studied, the mechanism of charge mobility is wave-like, rather than hopping, because we use the time dependent Schrödinger equation to propagate the electronic wave function.

Photoinduced charge transfer and excitonic energy transfer in the CuInS2/ZnS/MoS2 heterotrilayer

Photo-induced charge transfer is the key process of many applications such as photovoltaics, photodetection, and light-emitting devices. With the outgrowth of a new class of low-dimensional semiconductors, i.e., monolayer transition metal dichalcogenides and semiconductor nanocrystals, charge transfer at the 2D/0D heterostructures has drawn many efforts because of the outstanding optical and electrical properties. This paper studies the dynamics of excitons of the CuInS2/ZnS/MoS2 heterotrilayer through femtosecond time-resolved transient absorption spectroscopy. The electron and hole transfer are observed by selectively exciting the electrons with tunable pump wavelengths. The exciton lifetimes are obtained on the picosecond scale. This work provides clues on exploring the non-toxic optoelectronic devices based on the CuInS2/ZnS/MoS2 heterotrilayer.

Vibrational Relaxation Completes the Excitation Energy Transfer and Localization of Vibronic Excitons in Allophycocyanin α84-β84.

Phycobilisomes are light-harvesting complexes that play a key role in photosynthesis in cyanobacteria, which generate more than 40% of the world's oxygen. The near-unity excitation energy transfer efficiency from phycobilisomes to photosystems highlights its importance in understanding efficient energy transfer processes. Spectroscopic studies have shown that the 280 fs rapid excitonic downhill energy transfer within the α84-β84 chromophore dimer in allophycocyanin (APC), a subunit of phycobilisomes, is crucial to this efficiency. However, the role of strong chromophore-protein interactions and vibrational relaxation requires further exploration to fully explain this efficient downhill energy transfer. A theory is required that adequately describes exciton dynamics in an intermediate region while also incorporating vibrational relaxation mediated by protein bath modes. In this work, we incorporate vibrational relaxation into modified Redfield theory by introducing coupling fluctuation. We holistically simulate the rapid excitation energy transfer process of the α84-β84 chromophore dimer in APC and successfully model the recently observed rapid energy capture. We find that vibrational relaxation dictates capture of excitons by the localized state of the β84 chromophore. The calculated rate shows excellent agreement with previous ultrafast spectroscopic experiments. Our results show that the inclusion of vibrational relaxation is essential for systems that utilize vibronic coupling to enhance energy transfer and capture. Consequently, incorporating vibrational relaxation into Modified Redfield theory shows promise for accurately describing the excitation energy transfer process in other photosynthetic systems.

Sensitive Self-Driven Single-Component Organic Photodetector Based on Vapor-Deposited Small Molecules.

Typically, organic solar cells (OSCs) and photodetectors (OPDs) comprise an electron donating and accepting material to facilitate efficient charge carrier generation. This approach has proven successful in achieving high-performance devices but has several drawbacks for upscaling and stability. This study presents a fully vacuum-deposited single-component OPD, employing the neat oligothiophene derivative DCV2-5T in the photoactive layer. Free charge carriers are generated with an internal quantum efficiency of 20 % at zero bias. By optimizing the device structure, a very low dark current of 3.4 · 10-11Acm-2 at -0.1V is achieved, comparable to the dark current of state-of-the-art bulk heterojunction OPDs. This optimization results in specific detectivities of 1· 1013Jones (based on noise measurements), accompanied by a fast photoresponse (f-3dB = 200kHz) and a broad linear dynamic range (>150dB). Ultrafast transient absorption spectroscopy unveils that charge carriers are already formed at very short time scales (<1ps). The surprisingly efficient bulk charge generation mechanism is attributed to a strong electronic coupling of the molecular exciton and charge transfer states. This work demonstrates the very high performance of single-component OPDs and proves that this novel device design is a successful strategy for highly efficient, morphological stable and easily manufacturable devices.

Visualizing Triplet Energy Transfer in Organic Near-Infrared Phosphorescent Host-Guest Materials.

Limited by the energy gap law, purely organic materials with efficient near-infrared room temperature phosphorescence are rare and difficult to achieve. Additionally, the exciton transition process among different emitting species in host-guest phosphorescent materials remains elusive, presenting a significant academic challenge. Herein, using a modular nonbonding orbital-π bridge-nonbonding orbital (n-π-n) molecular design strategy, we develop a series of heavy atom-free phosphors. Systematic modification of the π-conjugated cores enables the construction of a library with tunable near-infrared phosphorescence from 655 to 710 nm. These phosphors exhibit excellent performance under ambient conditions when dispersed into a 4-bromobenzophenone host matrix, achieving an extended lifetime of 11.25 ms and a maximum phosphorescence efficiency of 4.2 %. Notably, by eliminating the interference from host phosphorescence, the exciton transition process in hybrid materials can be visualized under various excitation conditions. Spectroscopic analysis reveals that the improved phosphorescent performance of the guest originates from the triplet-triplet energy transfer of abundant triplet excitons generated independently by the host, rather than from enhanced intersystem crossing efficiency between the guest singlet state and the host triplet state. The findings provide in-depth insights into constructing novel near-infrared phosphors and exploring emission mechanisms of host-guest materials.

Visualizing Triplet Energy Transfer in Organic Near‐Infrared Phosphorescent Host‐Guest Materials

AbstractLimited by the energy gap law, purely organic materials with efficient near‐infrared room temperature phosphorescence are rare and difficult to achieve. Additionally, the exciton transition process among different emitting species in host–guest phosphorescent materials remains elusive, presenting a significant academic challenge. Herein, using a modular nonbonding orbital‐π bridge‐nonbonding orbital (n‐π‐n) molecular design strategy, we develop a series of heavy atom‐free phosphors. Systematic modification of the π‐conjugated cores enables the construction of a library with tunable near‐infrared phosphorescence from 655 to 710 nm. These phosphors exhibit excellent performance under ambient conditions when dispersed into a 4‐bromobenzophenone host matrix, achieving an extended lifetime of 11.25 ms and a maximum phosphorescence efficiency of 4.2 %. Notably, by eliminating the interference from host phosphorescence, the exciton transition process in hybrid materials can be visualized under various excitation conditions. Spectroscopic analysis reveals that the improved phosphorescent performance of the guest originates from the triplet‐triplet energy transfer of abundant triplet excitons generated independently by the host, rather than from enhanced intersystem crossing efficiency between the guest singlet state and the host triplet state. The findings provide in‐depth insights into constructing novel near‐infrared phosphors and exploring emission mechanisms of host–guest materials.

Interfacial Exciton-Polaron Quenching in Organic Light-Emitting Diodes

In organic light-emitting diodes (OLEDs), understanding the efficiency loss mechanism known as exciton-polaron quenching (EPQ) has been a longstanding challenge. Traditionally, EPQ was believed to occur mainly the bulk of the OLED emission layer (EML) due to the coexistence of polarons and excitons, limiting our understanding of its full impact. Here, we report a previously overlooked phenomenon termed “interfacial EPQ (Inf. EPQ),” which occurs at the heterointerface between the EML and the adjacent charge transport layer (CTL). We observe the transfer of EML excitons to CTL polarons across this interface, spanning distances of up to 4 nm. Notably, Inf. EPQ exceeds EPQ within the EML bulk, even in devices with a interfacial energy barrier (&gt;0.2 eV). We propose a methodology that enables independent probing of Inf. EPQ, systematic validation of its essential parameters, and the identification of Dexter energy transfer as its governing mechanism. Importantly, our findings highlight Inf. EPQ as a phenomenon across devices with various luminescent mechanisms, wavelengths, and injection levels. By effectively addressing Inf. EPQ, we achieve efficiency enhancements in red, green, and blue phosphorescent OLEDs, by 70%±8%, 47%±5%, and 66%±6%, respectively. Our work advances the physical understanding of exciton and polaron dynamics at organic heterointerfaces, providing applicable solutions to Inf. EPQ-related issues in practical devices. Published by the American Physical Society 2024

Enhanced Photocatalytic Degradation Performance by Micropore-Confined Charge Transfer in Hydrogen-Bonded Organic Framework-Like Cocrystals.

Carrier utilization in organic photocatalytic materials is unsatisfactory due to the large exciton binding energy and short exciton diffusion length. Both donor-acceptor (D-A) strategies and porous designs are promising approaches to improve carrier utilization in photocatalysts. However, a more efficient way is to shorten the distance of exciton migration to the catalyst surface by the charge transfer (CT) process. Herein, hydrogen-bonded organic framework-like cocrystal (NDI-Cor HOF-cocrystal) is prepared with novel structures serving as a proof of concept for the approach, using N, N'-bis (5-isophthalate) naphthalimide (NDI-COOH) as the porous framework and acceptor, and Coronene (Cor) as the donor unit. CT and porous engineering are integrated through cocrystal strategy. Under light irradiation, photogenerated excitons transfer and dissociate from the inner surface of the micropores on a hundred-picosecond time scale, where efficient radical transformation and further redox reactions with adsorbed phenol molecules occur. NDI-Cor HOF-cocrystal photocatalytic degradation of phenol is 15 times higher than that of original HOFs, and achieves near 90% deep mineralization of phenol. Significantly, this work has designed novel HOF-cocrystal and also provides new modification strategies for high performance organic photocatalysts.

Understanding and Improving Triplet Exciton Transfer in Sensitized Silicon Solar Cells

Understanding and Improving Triplet Exciton Transfer in Sensitized Silicon Solar Cells

Temporal witnesses of non-classicality in a macroscopic biological system

Exciton transfer along a bio-polymer is essential for many biological processes, for instance, light harvesting in photosynthetic biosystems. Here we apply a new witness of non-classicality to this phenomenon, to conclude that, if an exciton can mediate the coherent quantum evolution of a photon, then the exciton is non-classical. We then propose a general qubit model for the quantum transfer of an exciton along a bio-polymer chain, also discussing the effects of environmental decoherence. The generality of our results makes them ideal candidates to design new tests of quantum features in complex bio-molecules.

Fluorine substitution for aggregation transformation and exciton dissociation acceleration in non-fused electron acceptors

In order to enable low-cost manufacture of organic solar cells (OSCs), it is very important to develop non-fused electron acceptors to match with one of the cheapest polymer donors, poly(3-hexylthiophene) (P3HT). However, the lower exciton dissociation and charge transfer are still the main factors that limit the improvement of P3HT-based OSCs. Herein, we designed one class of A2-A1-D-A1-A2 type non-fused electron acceptors and synthesized BTA34 and F-BTA34 by introducing benzo[d][1,2,3] triazole as the bridged unit. The dominated H-aggregation in F-BTA34 affords high degree of crystalline and proper phase separation when blended with polymer P3HT, which ensure efficient exciton dissociation and higher charge carrier mobility. Consequently, P3HT:F-BTA34 devices demonstrate a better performance with higher short-circuit current and fill factor. The blend of P3HT:BTA34 exhibits a broader distribution of the mixing domains, resulting in relative longer-lived charge species. This work provides useful strategies to design non-fused electron acceptors to match with P3HT from the perspective of simultaneously improving exciton dissociation and suppressing charge recombination.

Rational Design of Organic Emitters with Inverted Singlet-Triplet Gaps for Enhanced Exciton Management.

In organic light-emitting diodes (OLEDs), the pursuit of efficient molecular emitters has led to the development of thermally activated delayed fluorescence (TADF) molecules. While TADF compounds have promising properties, they face challenges such as energy gap constraints and uphill exciton transfer. Inverted emitters (INVEST) offer a novel solution with an inverted singlet-triplet energy (ΔEST) gap, enabling efficient utilization of excitons. This study examines the design and computational analysis of an array of molecules, including 23 INVEST emitters and remaining with positive energy gaps. Within the STEOM-DLPNO-CCSD framework, we explore the role of various molecular fragments in determining ΔEST. We also assess the importance of dynamic spin-polarization (DSP) obtained via the Pariser-Parr-Pople (PPP) scheme in energy gap determination. Exciting trends emerged from our results, with pentalene-containing compounds consistently manifesting negative ΔEST values while their naphthalene counterparts exhibited contrasting behavior. Moreover, we observed a negative DSP correlates with inverted singlet-triplet gaps. Overall, this research advances OLED materials through molecular design and computational analysis, offering avenues for optimizing exciton management and enhancing device performance.

Nonadiabatic Exciton Dynamics and Energy Gradients in the Framework of FMO-LC-TDDFTB.

We introduce a novel methodology for simulating the excited-state dynamics of extensive molecular aggregates in the framework of the long-range corrected time-dependent density-functional tight-binding fragment molecular orbital method (FMO-LC-TDDFTB) combined with the mean-field Ehrenfest method. The electronic structure of the system is described in a quasi-diabatic basis composed of locally excited and charge-transfer states of all fragments. In order to carry out nonadiabatic molecular dynamics simulations, we derive and implement the excited-state gradients of the locally excited and charge-transfer states. Subsequently, the accuracy of the analytical excited-state gradients is evaluated. The applicability to the simulation of exciton transport in organic semiconductors is illustrated on a large cluster of anthracene molecules. Additionally, nonadiabatic molecular dynamics simulations of a model system of benzothieno-benzothiophene molecules highlight the method's utility in studying charge-transfer dynamics in organic materials. Our new methodology will facilitate the investigation of excitonic transfer in extensive biological systems, nanomaterials, and other complex molecular systems consisting of thousands of atoms.

(Invited) Resonant Exciton Transfer in Mixed-Dimensional Heterostructures for Overcoming Dimensional Restrictions in Optical Processes

Nanomaterials exhibit unique optical phenomena, in particular excitonic quantum processes occurring at room temperature. The low dimensionality, however, imposes strict requirements for conventional optical excitation, and an approach for bypassing such restrictions is desirable. Here we report on exciton transfer in carbon-nanotube/tungsten-diselenide heterostructures, where band alignment can be systematically varied. The mixed-dimensional heterostructures display a pronounced exciton reservoir effect where the longer-lifetime excitons within the two-dimensional semiconductor are funneled into carbon nanotubes through diffusion. This new excitation pathway presents several advantages, including larger absorption areas, broadband spectral response, and polarization-independent efficiency. When band alignment is resonant, we observe substantially more efficient excitation via tungsten diselenide compared to direct excitation of the nanotube. We further demonstrate simultaneous bright emission from an array of carbon nanotubes with varied chiralities and orientations. Our findings show the potential of mixed-dimensional heterostructures and band alignment engineering for energy harvesting and quantum applications through exciton manipulation.Parts of this study are supported by JSPS (KAKENHI JP22K14624, JP22K14625, JP21K14484, JP22F22350, JP22K14623, JP21H05233, JP23H00262, JP20H02558) and MEXT (ARIM JPMXP1222UT1135). Y.R.C. is supported by JSPS (International Research Fellow). N.F. and C.F.F. are supported by RIKEN Special Postdoctoral Researcher Program. We thank the Advanced Manufacturing Support Team at RIKEN for technical assistance.[1] N. Fang, D. Yamashita, S. Fujii, M. Maruyama, Y. Gao, Y. R. Chang, C. F. Fong, K. Otsuka, K. Nagashio, S. Okada, Y. K. Kato, "Resonant exciton transfer in mixed-dimensional heterostructures for overcoming dimensional restrictions in optical processes," Nature Commun., accepted (2023). Preprint at arXiv:2307.07124.

Ultrafast Charge Transfer Cascade in a Mixed-Dimensionality Nanoscale Trilayer

Innovation in optoelectronic semiconductor devices is driven by a fundamental understanding of how to move charges and/or excitons (electron-hole pairs) in specified directions for doing useful work, e.g. for making fuels or electricity. The diverse and tunable electronic and optical properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) and one-dimensional (1D) semiconducting single-walled carbon nanotubes (s-SWCNTs) make them good quantum confined model systems for fundamental studies on charge and exciton transfer across heterointerfaces. In nature, the photosynthetic apparatus achieves long-lived charge separation through a charge transfer cascade that consists of a series of thermodynamically downhill charge transfer reactions. Inspired by photosynthesis we create a unique mixed-dimensionality 2D/1D/2D MoS2/SWCNT/WSe2 hetero-trilayer. Photoexcitation of this trilayer heterostructure allows us to overcome both intralayer and interlayer exciton binding energies, resulting in coulombically unbound charges with microsecond recombination lifetimes. In contrast to previously demonstrated 2D/2D/2D trilayers based solely on monolayer TMDC layers, the very large charge mobilities and extended electron network of the 1D semiconducting SWCNT layer helps charges delocalize and diffuse away from the interface at which each type of charge is generated. Interestingly, the hetero-trilayer also appears to enable efficient hole transfer from SWCNTs to WSe2, which is not observed in the identically prepared WSe2/SWCNT heterobilayer, suggesting that new dynamic pathways may be opened by increasing the complexity of nanoscale heterostructures. Our work suggests "mixed-dimensionality" TMDC/SWCNT based hetero-trilayers as both interesting model systems for mechanistic studies of carrier dynamics at nanoscale heterointerfaces, and for potential applications in advanced optoelectronic systems.

Exciton energy transfer inside cavity-A benchmark study of polaritonic dynamics using the surface hopping method.

Strong coupling between the molecular system and photon inside the cavity generates polaritons, which can alter reaction rates by orders of magnitude. In this work, we benchmark the surface hopping method to simulate non-adiabatic dynamics in a cavity. The comparison is made against a numerically exact method (the hierarchical equations of motion) for a model system investigating excitonic energy transfer for a broad range of parameters. Surface hopping captures the effects of the radiation mode well, both at resonance and off-resonance. We have further investigated parameters that can increase or decrease the rate of population transfer, and we find that surface hopping in general can capture both effects well. Finally, we show that the dipole self-energy term within our parameter regime does not significantly affect the system's dynamics.

Coarse-Grained Approach to Simulate Signatures of Excitation Energy Transfer in Two-Dimensional Electronic Spectroscopy of Large Molecular Systems.

Two-dimensional electronic spectroscopy (2DES) has proven to be a highly effective technique in studying the properties of excited states and the process of excitation energy transfer in complex molecular assemblies, particularly in biological light-harvesting systems. However, the accurate simulation of 2DES for large systems still poses a challenge because of the heavy computational demands it entails. In an effort to overcome this limitation, we devised a coarse-grained 2DES method. This method encompasses the treatment of the entire system by dividing it into distinct weakly coupled segments, which are assumed to communicate predominantly through incoherent exciton transfer. We first demonstrate the efficiency of this method through simulation on a model dimer system, which demonstrates a marked improvement in calculation efficiency, with results that exhibit good concordance with reference spectra calculated with less approximate methods. Additionally, the application of this method to the light-harvesting antenna 2 (LH2) complex of purple bacteria showcases its advantages, accuracy, and limitations. Furthermore, simulating the anisotropy decay in LH2 induced by energy transfer and its comparison with experiments confirm that the method is capable of accurately describing dynamical processes in a biologically relevant system. This method presented lends itself to an extension that accounts for the effect of intrasegment relaxation processes on the 2DES spectra, which for computational efficiency are ignored in the implementation reported here. It is envisioned that the method will be employed in the future to accurately and efficiently calculate 2D spectra of more extensive systems, such as photosynthetic supercomplexes.

Robust and Efficient Out-of-Plane Exciton Transport in Two-Dimensional Perovskites via Ultrafast Förster Energy Transfer.

Two-dimensional (2D) perovskites, comprising inorganic semiconductor layers separated by organic spacers, hold promise for light harvesting and optoelectronic applications. Exciton transport in these materials is pivotal for device performance, often necessitating deliberate alignment of the inorganic layers with respect to the contacting layers to facilitate exciton transport. While much attention has focused on in-plane exciton transport, little has been paid to out-of-plane interlayer transport, which presumably is sluggish and unfavorable. Herein, by time-resolved photoluminescence, we unveil surprisingly efficient out-of-plane exciton transport in 2D perovskites, with diffusion coefficients (up to ∼0.1 cm2 s-1) and lengths (∼100 nm) merely a few times smaller or comparable to their in-plane counterparts. We unambiguously confirm that the out-of-plane exciton diffusion coefficient corresponds to a subpicosecond interlayer exciton transfer, governed by the Förster resonance energy transfer (FRET) mechanism. Intriguingly, in contrast to temperature-sensitive intralayer band-like transport, the interlayer exciton transport exhibits negligible temperature dependence, implying a lowest-lying bright exciton state in 2D perovskites, irrespective of spacer molecules. The robust and ultrafast interlayer exciton transport alleviates the constraints on crystal orientation that are crucial for the design of 2D perovskite-based light harvesting and optoelectronic devices.

Efficient C(sp3)-H Bond Oxidation on Perovskite Quantum Dots Based on Ce-Oxygen Affinity.

Perovskite quantum dots (QDs) have shown attractive prospects in the field of visible photocatalysis, especially in the synthesis of high value-added chemicals. However, under aerobic conditions, the stable operation of QD catalysts has been limited by the reactive oxygen species (ROS) generated by photoexcitation, especially superoxide species O2⋅-. Here, we propose a strategy of Ce3+ doping in perovskite QDs to guide superoxide species for photocatalytic oxidation reactions. In C(sp3)-H bond oxidation of hydrocarbons, superoxide species were rapidly generated and efficiently utilized on the surface of perovskite QDs, which achieves the stable operation of the catalytic system and obtains a high product conversion rate (15.3 mmol/g/h for benzaldehydes). The mechanism studies show that the strong Ce-oxygen affinity accelerates the relaxation process of photoinduced exciton transfer to superoxide species and inhibits the radiative recombination pathway. This work provides a new idea of utilizing oxygen species on perovskite surface and broadens the design strategy of high-performance QD photocatalysts.