Heterostructure Interface Research Articles

Tunable and efficient electromagnetic wave absorption of carbon material modulating magnetic ionic polymer-based composites

Developing the miniaturization and intellectualization of carbon-based chips and electronic devices is extremely desirable but remains hampered by electromagnetic interference. Magnetic ionic polymer (MIP) holds great promise for electromagnetic-absorbing material in the field of electromagnetic reliability of communication equipment due to its dielectric loss and magnetic loss are obviously higher than other commonly polymers. However, it remains a formidable challenge for MIP to achieve satisfactory absorption of electromagnetic wave (EMW). Herein, we achieved the excellent EMW absorbing performance of the poly[1-allyl-3-vinylimidazolium tetrachloroferrate]/carbon nanotube/reduced graphene oxide (P[AVIm][FeCl4]/CNT/rGO) composites when the only carbon materials loading of 10 wt%. Most strikingly, the effective absorption bandwidth (EAB) is as wide as 5.63 GHz, the lowest reflection loss can reach up to −51.05 dB with the absorber thickness of 2.2 mm. The enhancement in microwave absorption efficiency of P[AVIm][FeCl4]/CNT/rGO composites are arisen from the synergistic effects in its unique multicomponent heterostructure interface, which causes multiple reflections and strong conduction loss, further suitable impedance matching ratio and favorable attenuation ability. This work proposes a new perspective approach and fundamental absorption mechanisms to realize excellent performance EMW absorption.

Fast fabrication technique for high-quality van der Waals heterostructures using inert shielding gas environment

Abstract2D materials based on van der Waals heterostructures have remarkable applications in electronic devices. However, trapped contaminations between the interface heterostructure layers during fabrication processes degrade the device performance. Here, we report a novel fabrication method to prevent contamination of the device from air impurities to obtain atomically clean interfaces using an Argon shielding gas environment. Large-area graphene encapsulated with hexagonal boron nitride, approximately ∼12,637 μm2, has been fabricated. Using the proposed methodology, high graphene mobility up to 600 000 cm2V−1s−1 at room temperature has been achieved. The theoretical analysis combined with a molecular dynamic simulation model was utilized to improve the dry transfer technique for large-scale fabrication of 2D materials.

Simultaneous benzyl alcohol oxidation and H2 generation over MOF/CdS S-scheme photocatalysts and mechanism study

The conversion from solar energy into storable chemical energy can be achieved through synergistic coupling of photocatalytic H2 production and organic synthesis, during which photogenerated electrons and holes can be simultaneously utilized. Herein, we combined a zirconium-based metal-organic framework, UiO-66-NH2, and CdS nanoparticles (NPs) to form a core-shell structure by a chemical bath method. The step-scheme (S-scheme) heterojunction exhibits both substantially enhanced selective oxidation of benzyl alcohol and efficient H2 generation under light irradiation simultaneously. The electron transfer paths at the S-scheme heterostructure interface were investigated in depth by in situ irradiated X-ray photoelectron spectroscopy. The dynamics of carrier migration at the heterojunction were obtained through femtosecond transient absorption (fs-TA) spectroscopy. Furthermore, the evolution mechanism of benzaldehyde was revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy and electron paramagnetic resonance. This work illustrates the electron transfer mechanism of S-scheme heterojunction by fs-TA spectroscopy and provides new insights into the design of MOF/inorganic composite photocatalysts.

Proximity-Induced Tunable Magnetic Order at the Interface of All-van der Waals-Layered Heterostructures.

Spin-orbit coupling (SOC) plays a crucial role in controlling the spin-charge conversion efficiency, spin torque, and complex magnetic spin structures. In this study, we investigate the interplay between SOC and ferromagnetism in heterostructures of large-SOC and magnetic materials. We highlight the importance of the SOC-proximity effect on magnetic ordering in all-van der Waals-layered heterostructures, specifically Fe3GeTe2(FGT)/monolayer W1-xVxSe2 (x = 0 and 0.05). By increasing the SOC strength, we demonstrate various magnetic orderings induced at the interface of the heterostructure, including spin-flop, spin-flip, and inverted magnetization. Moreover, we show a sharp magnetic switching from antiferromagnetic state to ferromagnetic state in FGT/W0.95V0.05Se2, which is characteristic of the synthetic antiferromagnetic structure. This proof-of-concept result offers the possibility of interface-tailoring spintronics, including two-dimensional magnetoresistive random access memory toggle switching. Our findings provide insight into the design and development of next-generation spintronic devices by exploiting the interplay between SOC and magnetic ordering in all-van der Waals-layered heterostructures.

Ni-CeO2 Heterostructure Promotes Hydrogen Evolution Reaction via Tuning of the O-H Bond Length of Adsorbed Water at the Electrolyte/Electrode Interface.

Understanding the properties and structure of reactant water molecules at the electrolyte solution/electrode interface is relevant to know the mechanisms of hydrogen evolution reaction (HER). However, this approach has rarely been implemented due to the elusive local microenvironment in the vicinity of the catalyst. Taking the Ni-CeO2 heterostructure immobilized onto carbon paper (Ni-CeO2 /CP) as a model, the dynamic behavior of adsorbed intermediates during the reaction was measured by in situ surface-enhanced infrared absorption spectroscopy with attenuated total reflection configuration (ATR-SEIRAS). Theoretical calculations are used in combination to comprehend the potential causes of increased HER activity. The results show that the O-H bond of adsorbed water at the electrolyte solution/electrode interface becomes longer for promoting the dissociation of water and accelerating the kinetically slow Volmer step. In addition, forming the Ni-CeO2 heterostructure interface optimizes the hydrogen adsorption Gibbs free energy, thus increasing HER activity. Therefore, the Ni-CeO2 /CP electrode exhibits remarkably low HER overpotentials of 37 and 119 mV at 10 and 100 mA cm-2 , which are close to commercial Pt/C (16 and 102.6 mV, respectively).

VOC Bonding of Heterointerface Boosting Kinetics of Free‐Standing Na5V12O32 Cathode for Ultralong Lifespan Sodium‐Ion Batteries

AbstractThe flexible free‐standing cathodes with high energy density have been challenging toward wearable sodium‐ion batteries (SIBs). Herein, Na5V12O32 nanobelts (NVO‐NBs)‐based heterostructure is fabricated with boosting the sodium‐ion kinetic characteristics to address the challenges. In the heterostructure, the controllable VOC bonds are generated at the interface originating from the chemical conversion of functional groups of the reduced graphene oxides (rGOs) with VO bonding of NVO through interfacial electronic interactions. The interfacial synergistic between the brilliant bonding properties and the inherent formation of a stress field at the heterointerface motivated by work function difference can reduce the Na+ diffusion barrier, facilitate charge transfer, hence accelerates reaction kinetics and electron/ion transport, as well as modifying the electronic structure to realize a cherished adsorption energy of Na+. Therefore, the optimized NVO‐NBs‐based heterostructure exhibits exceptional rate capability (213 mAh g−1 at 0.2 C with 100 mAh g−1 at 10 C) and ultralong cycling stability (95.4%, 3000 cycles at 5 C). This work demonstrates that the controllable heterostructure interface with abundant chemical bonds is an effective approach to exploit potential cathodes for rechargeable batteries.

Improved PCE in stable lead-free perovskite solar cells based on band engineering of ETL and absorber

In this paper, a unique structure of graded band gap (GBG) electron transport layer (ETL) based lead-free Perovskite solar cell (PSC) is proposed and numerically investigated. The structure consists of cesium Formamidinium tin iodide (FACsSnI3) with band-gap grading aspect sandwiched between electron and hole transport layers. Various ETLs such as Zn(S,O), ZnO, ZnMgO and C60 have been considered and investigated with and without GBG aspect. It is revealed that the use of band engineering based on band gap grading ETL and absorber films allows the dual-advantages of enhanced photogeneration and carrier extraction mechanisms. The merits of the proposed PSC structure are compared to other published results in terms of improved photovoltaic parameters. The obtained results show improvements in photoconversion properties of the PSCs when GBG-Zn(S,O) is considered as an ETL. The effective conduction band alignment of GBG-Zn(S,O)/GBG-FACsSnI3 heterostructure interface leads to an improved carrier collection efficiency and subsequently improved efficiency. The optimized PSC structure presents power conversion efficiency as high as 21.67 %, with an open circuit voltage of 0.96 V, short-circuit current of 30.75 mA/cm2, and fill factor of 72.88%. The obtained photovoltaic parameters of the proposed GBG-ETL/GBG-FACsSnI3 heterostructure can provide new perspectives for the realization of efficient cost-effective lead-free PSCs.

Prediction of direct Z-scheme H and H́-phase of MoSi2N4/MoSX (X = S, Se) van der Waals heterostructures: A promising candidate for photocatalysis

Photocatalysis has emerged as an appealing strategy for environmental remediation and sustainable energy production. The density functional theory (DFT) approximations were employed to investigate the heterostructures (HTS) of 2H and 2H́ polymorphs of MoSi2N4/ MoSX (X = S, Se) for photocatalytic applications. To ensure their applicability for water-splitting photocatalysis, we examined the heterostructures for desirable electronic properties. The structures (except 2H́-MoSi2N4/MoSSe) have a direct Z-scheme type-II alignment which further favors the carrier separation causing hydrogen and oxygen production at distant positions. The bandgaps of structures lie within the desirable range of 1.23 to 3 eV, favoring visible light absorption. The difference in the work function of monolayers (of about 0.5 to 1 eV) develops an electric field at the interface of HTS, causing the separation of carriers. The reduction potential lies between −3.8 to −4.6 eV, while the oxidation potential lies between −5.7 to −6.2 eV. It indicates that although oxidation potentials incorporate water redox levels, reduction potentials of some HTS do not. To ensure HER, Gibbs free energies were calculated. The vacancy defects at S/Se site gave ΔGH∗ less than the catalytic threshold of 0.2 eV. Due to ultrafast charge transfer, broad spectral response, and improved photocatalytic capability due to the formation of radicals at the surface, heterostructures can act as a competitive choice over monolayers for water-splitting photocatalysis.

The reversible and nonvolatile properties of 2D LaBr2/α-In2Se3 heterostructure by strain and electric field modulation

Two-dimensional (2D) ferroelectric materials have intrinsic polarized electric field, when they stack with other 2D materials to construct ferroelectric van der Waals heterostructures, they will produce a lot of novel properties, which has aroused extensive research interests. Therefore, based on first-principle calculations, we have comprehensively studied the electronic properties of LaBr2/α-In2Se3 ferroelectric heterostructures to investigate the reversibility and nonvolatility with information. Our calculations show that, the system is a ferromagnetic semiconductor with intrinsic valley polarization when α-In2Se3 is in the ferroelectric polarized up state. By switching the ferroelectric polarization of α-In2Se3, the heterostructure undergoes a transition from semiconductor to half metal, which can be attributed to the competition between the built-in electric field (Eint) and the polarized electric field Epi→,generated by the charge transfer at interface of heterostructure and the bound charge of α-In2Se3, respectively. Besides, the band arrangement types of LaBr2/α-In2Se3 heterostructure can be well modulated under extra electric filed and biaxial strain. Furthermore, we have observed valley-submerging under electric filed and strain, which indicates the valleytronic nature can also be on-off in LaBr2/α-In2Se3 heterostructures. More importantly, the realization of reversible and non-volatile properties depends on the intrinsic characteristics of heterostructure and does not require external mechanisms. Our research not only provides the possibility for the application of the LaBr2/α-In2Se3 heterostructures in nanodevices, but also give the theoretical support to the study of spintronics and valleytronics.

Construction of CuBi2O4/CdO p-n buried junction for boosted photoelectrochemical water splitting

The rational design and construction of interface heterostructures, which can simultaneously accelerate the photoinduced carrier separation and enhance the surface hydrogen evolution kinetics, is of great necessity for photoelectrochemical (PEC) water splitting. Here we construct a CuBi2O4/CdO p-n buried junction for boosting the PEC hydrogen evolution. Compared to the bare CuBi2O4 photocathode, the CuBi2O4/CdO heterojunction reveals an anodic shift of 170 mV for the onset potential and achieves a cathodic photocurrent density of 0.32 mA cm−2 at 0.4 V vs. RHE, as well as improved long-term stability under AM 1.5 G illumination without sacrificial reagent. The experimental characterizations and theoretical calculations confirm the significance of the CuBi2O4/CdO p-n junction in increasing the photoinduced charge separation efficiency and reducing the activation energy of hydrogen evolution reaction (HER), which accounts for enhanced PEC performance. Meanwhile, the change of photoexcited charge-transition route evidenced by DFT calculation in CuBi2O4/CdO provides the fundamental explanation for spatial charge separation, which is responsible for the improved PEC hydrogen evolution stability. The present work highlights the importance of constructing heterojunctions to boost the PEC performance and elucidates the probable intrinsic mechanism involved in the interface.

Applying 2DEG in High‐Performance Mid‐Infrared Photodetection

AbstractHigh‐speed and highly sensitive infrared photodetectors are regarded as one of the most essential components in modern photonic devices and technology because of constantly emerging application scenarios. In this paper, an ultrafast and extremely low noise mid‐infrared (MIR) photodetector is reported at both room and cryogenic temperatures by leveraging the high‐mobility 2D electron gas (2DEG) at the polar CdTe/PbTe heterostructure interface. The detector simultaneously exhibits a peak detectivity of ≈4.2 × 1011 Jones with rapid response in the order of 10 ns, which is substantially superior to the state‐of‐the‐art 2DEG MIR detectors made of 2D layered materials. The ultrafast response with extremely low noise of the 2DEG photodetector is attributed to the unique band alignment at the interface. The practical infrared imaging application is further showcased using the 2DEG MIR detector by revealing the fine features of a MIR radiation target. This work highlights the promising prospect of utilizing the unique 2DEG interface in the field of high‐speed and highly sensitive MIR detection.

3D Strain Measurement of Heterostructures Using the Scanning Transmission Electron Microscopy Moiré Depth Sectioning Method.

The mechanical properties of micro- and nanoscale materials directly determine the reliability of heterostructures, microstructures, and microdevices. Therefore, an accurate evaluation of the 3D strain field at the nanoscale is important. In this study, a scanning transmission electron microscopy (STEM) moiré depth sectioning method is proposed. By optimizing the scanning parameters of electron probes at different depths of the material, the sequence STEM moiré fringes (STEM-MFs) with a large field of view, which can be hundreds of nanometers obtained. Then, the 3D STEM moiré information constructed. To some extent, multi-scale 3D strain field measurements from nanometer to the submicrometer scale actualized. The 3D strain field near the heterostructure interface and single dislocation accurately measured by the developed method.

Optical Switching of Hole Transfer in Double Perovskite/Graphene Heterostructure.

Synergically combining their respective ultrahigh charge mobility and strong light absorption, graphene (Gr)/semiconductor heterostructures are promising building blocks for efficient optoelectronics, particularly photodetectors. Charge transfer (CT) across the heterostructure interface crucially determines device efficiency and functionality. Here we report that hole transfer processes dominate the ultrafast CT across strongly coupled double perovskite Cs2 AgBiBr6 /graphene (DP/Gr) heterostructures following optical excitation. While holes are the primary charges flowing across interfaces, their transfer direction, as well as efficiency, show a remarkable dependence on the excitation wavelength. For excitation with photon energies below the bandgap of DPs, the photoexcited hot holes in graphene can compete with the thermalization process and inject into in-gap defect states in DPs. In contrast, above-bandgap excitation of DP reverse the hole transfer direction, leading to hole transfer from the valence band of DPs to Gr. We further provide experimental evidence that increasing the excitation photon energy enhances CT efficiency for both below- and above-bandgap photoexcitation regimes, unveiling the positive role of excess energy in enhancing interfacial CT. The possibility of switching the hole transfer direction and, thus, the interfacial photogating field by tuning the excitation wavelength, provides a novel way to control the interfacial charge flow across a DP/Gr heterojunction. This article is protected by copyright. All rights reserved.

Heterostructured Interface Enables Uniform Zinc Deposition for High-Performance Zinc-Ion Batteries.

Zinc metal has considerable potential as a high-energy anode material for aqueous batteries due to its high theoretical capacity and environmental friendliness. However, dendrite growth and parasitic reactions at the electrode/electrolyte interface remain two serious problems for the Zn metal anode. Here, the heterostructured interface of ZnO rod array and CuZn5 layer is fabricated on the Zn substrate (ZnCu@Zn) to address these two issues. The zincophilic CuZn5 layer with abundant nucleation sites ensures the initial uniform Zn nucleation process during cycling. Meanwhile, the ZnO rod array grown on the surface of the CuZn5 layer can guide the subsequent homogeneous Zn deposition via spatial confinement and electrostatic attraction effects, leading to the dendrite-free Zn electrodeposition process. Consequently, the derived ZnCu@Zn anode exhibits an ultra-long lifespan of up to 2500h with symmetric cells at the current density and capacity of 0.5mAcm-2 /0.5mAhcm-2 . Besides, a remarkable cyclability (75% retention for 2500 cycles at 2Ag-1 ) is achieved in the ZnCu@Zn||MnO2 full cell with a capacity of 139.7mAhg-1 . This heterostructured interface with specific functional layers provides a feasible strategy for the design of high-performance metal anodes.

XFEM for multiphysics analysis of edge dislocations with nonuniform misfit strain: A novel enrichment implementation

In this work, the eXtended finite element method (XFEM) is implemented for the multiphysics analysis of edge dislocations near a heterostructure (bi-material) interface with nonuniform misfit strain. A novel enrichment is defined to incorporate the singular behavior of the electric potential due to dislocation. Nonlinear material properties due to temperature are taken for a thermo-electro-elastic analysis. The constituting materials having different lattice parameters result in a mismatch–misfit​ strain near the interface. This nonuniform misfit strain distribution affects the dislocations near the bi-material interface. Volterra dislocation modeling is performed to obtain all the primary and secondary fields around dislocations. An expression of the Peach–Koehler force considering the combined effect of the multiple fields is proposed. The results are obtained when the misfit strain is present on one side of the interface and both sides of the interface. A comparative study is performed on the Peach–Koehler force obtained in different cases of the misfit consideration with the case when the misfit strain is absent. Also for the case when the misfit strain is taken on the same side of the interface, the Peach–Koehler force is obtained by varying the misfit percentages corresponding to the different amounts of misfit relaxation.

Recent Advances and Perspectives in Ru Hybrid Electrocatalysts for the Hydrogen Evolution Reaction

The water-splitting reaction for green hydrogen generation requires highly efficient catalysts on the side for the hydrogen evolution reaction (HER), and metal ruthenium (Ru) is considered a promising catalyst as a result of its similar property in hydrogen-bonding ability but low cost compared to Pt-based materials. The performance is further boosted by the recently developed hybrid Ru-based electrocatalysts. To reveal the relationship between the hybrid catalyst systems and activity for Ru-based catalysts, the research progress of heterostructured Ru hybrid catalysts in the HER is reviewed in this effort. The enhancement of HER activity of Ru hybrid catalysts is first described on the basis of the synergistic effect, strain effect, and electronic effect, and then, the latest progress is discussed in three categories of single ruthenium catalysts, ruthenium-related compounds, and ruthenium alloy catalysts. It is concluded that the heterostructured interface engineering strategy plays an important role in enhancing the activity of Ru-based catalysts in the HER. In the end, the actual problems and challenges are discussed, e.g., the intrinsic activity and stability, application in the real device, etc. It is recommended to pay attention to the long-term stability, performance, and structural evolution as well as the application of the catalysts in the devices. It is hoped that this effort will help with understanding the progress of Ru-based hybrid catalysts in the field of HER catalysis.

Core-Shell Spheroid Structure TiO2/CdS Composites with Enhanced Photocathodic Protection Performance.

In order to improve the conversion and transmission efficiency of the photoelectron, core-shell spheroid structure titanium dioxide/cadmium sulfide (TiO2/CdS) composites were synthesized as epoxy-based coating fillers using a simple hydrothermal method. The electrochemical performance of photocathodic protection for the epoxy-based composite coating was analyzed by coating it on the Q235 carbon steel surface. The results show that the epoxy-based composite coating possesses a significant photoelectrochemical property with a photocurrent density of 0.0421 A/cm2 and corrosion potential of -0.724 V. Importantly, the modified composite coating can extend absorption in the visible region and effectively separate photoelectron hole pairs to improve the photoelectrochemical performance synergistically, because CdS can be regarded as a sensitizer to be introduced into TiO2 to form a heterojunction system. The mechanism of photocathodic protection is attributed to the potential energy difference between Fermi energy and excitation level, which leads to the system obtaining higher electric field strength at the heterostructure interface, thus driving electrons directly into the surface of Q235 carbon steel (Q235 CS). Moreover, the photocathodic protection mechanism of the epoxy-based composite coating for Q235 CS is investigated in this paper.

Improving Charge Injection for Organic Field‐Effect Transistor Array via Chemical Functionalized Van der Waals Top‐Contacts

AbstractEfficient charge injection at metal/semiconductor interface is of great importance for high‐performance organic field‐effect transistors (OFETs). In OFETs, top‐contact configuration generally exhibits better injection efficiency but may induces thermal damage to organic layer and is intrinsically difficult to modified with chemisorbs at metal/semiconductor interface. Herein, a versatile, large‐scale and damage‐free metal integration strategy is reported to achieve efficient charge injection in OFETs by applying self‐assembly monolayers (SAMs) functionalized van der Waals (vdW) top‐contact electrodes. Centimeter scale metal electrodes are transferred onto organic single crystal to form OFETs array without residual left. vdW contact provides a clear and atomic sharp interface, and thus the inherent electronic structure and physical properties of the pristine heterostructure interface can be retained. Modifying fluorinated SAMs at metal/semiconductor interface alters the work function of Au by 350 meV, and thus reduces the energy barrier for charge injection. As a result, OFETs array exhibits excellent performance characteristics with an average mobility of 3.6 cm2 V−1 s−1, negligible hysteresis and a high on/off ratio above 106 on high‐k AlOx dielectric. Organic unipolar inverters based on all vdW contact are also demonstrated. This strategy paves the way for both fundamental study and practical applications of organic electronics.

Heterostructure Interface Engineering in CoP/FeP/CeOx with a Tailored d-Band Center for Promising Overall Water Splitting Electrocatalysis

Accomplishing a green hydrogen economy in reality through water spitting ultimately relies upon earth-abundant efficient electrocatalysts that can simultaneously accelerate the oxygen and hydrogen evolution reactions (OER and HER). The perspective of electronic structure modulation via interface engineering is of great significance to optimize electrocatalytic output but remains a tremendous challenge. Herein, an efficient tactic has been explored to prepare nanosheet-assembly tumbleweed-like CoFeCe-containing precursors with time-/energy-saving and easy-operating features. Subsequently, the final metal phosphide materials containing multiple interfaces, denoted CoP/FeP/CeOx, have been synthesized via the phosphorization process. Through the optimization of the Co/Fe ratio and the content of the rare-earth Ce element, the electrocatalytic activity has been regulated. As a result, bifunctional Co3Fe/Ce0.025 reaches the top of the volcano for both OER and HER simultaneously, with the smallest overpotentials of 285 mV (OER) and 178 mV (HER) at 10 mA cm-2 current density in an alkaline environment. Multicomponent heterostructure interface engineering would lead to more exposed active sites, feasible charge transport, and strong interfacial electronic interaction. More importantly, the appropriate Co/Fe ratio and Ce content can synergistically tailor the d-band center with a downshift to enhance the per-site intrinsic activity. This work would provide valuable insights to regulate the electronic structure of superior electrocatalysts toward water splitting by constructing rare-earth compounds containing multiple heterointerfaces.

Slow Cooling and Transfer Dynamics of Hot Excitons in CsPbBr3 Perovskite Quantum Dots/g-CN Nanosheet Heterostructures: Implications for Optoelectronic Applications

Slow cooling and long-lived hot carrier (HC) population plays a crucial role in crossing the Shockley–Queisser limit and achieving high-efficiency perovskite photovoltaic devices up to 66%. Herein, we investigated the slow cooling of HCs via charge transfer in in-situ synthesized CsPbBr3 perovskite quantum dots-decorated graphitic carbon nitride nanosheet (CsPbBr3 PQDs/g-CN NS) heterostructures using ultrafast transient absorption (UTA) spectroscopy. Halide perovskites showed excitation energy-dependent HC cooling. We examined the HC dynamics at two different excitation energies with varying excitation pump fluences. UTA revealed significantly higher slow cooling and slow bleach recovery in CsPbBr3 PQDs/g-CN NSs (i.e., 632 fs and 845 ps) compared to pure CsPbBr3 PQDs (i.e., 512 fs and 371 ps) at an excitation energy of 3.54 eV and a fluence of 250 μW, suggesting that HCs transfer through the heterostructure interface. The observed slow cooling can be explained by the stronger interaction between the organic polymeric frameworks of g-CN NSs and CsPbBr3 PQDs, which passivates the trap states of CsPbBr3 PQDs and offers slow electron–hole recombination by slowing down the Auger recombination or the hot-phonon bottleneck effect. Additionally, density functional theory (DFT) calculations were carried out to shed light on band alignment at the interface to reveal the mechanism of efficient charge transfer in CsPbBr3 PQDs/g-CN NSs and validate the experimental findings. The insight of this study is quite beneficial for designing modified perovskite nanostructures for realization in perovskite solar cells in the near future.