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Highly Efficient and Stable CsPbBr3 Perovskite Quantum Dots by Encapsulating in Dual-Shell Hollow Silica Spheres for WLEDs
摘要： Poor stability of CsPbX3 (X = Cl, Br or I) perovskite quantum dots (QDs) has greatly hindered their practical photoelectric applications, and how to improve it still remains a critical challenge. Herein, we encapsulated the CsPbBr3 QDs into a dual-shell hollow silica (SiO2) spheres via a simple successive ionic layer adsorption and reaction (SILAR) method. The hierarchical dual-shell structures permit CsPbBr3 QDs to be anchored on the interior of the SiO2 spheres while keeping the outside surface undisturbed, which can protect CsPbBr3 QDs from direct exposure to the atmosphere. Due to the comprehensive protection of dual-shell hollow SiO2 spheres, the CsPbBr3/SiO2 nanospheres exhibit markedly enhanced stability against light and heat, with residual PL intensity of 89% after continuous exposure of 72 h to UV light and 65% at 100?C heat treatment, respectively. In addition, an optimal PLQY of 89% is obtained with suppressed nonradiative recombination. Finally, the fabricated white light-emitting diodes (LEDs) device by employing CsPbBr3/SiO2 green phosphors could achieve a wide color gamut covering up to 136% of the NTSC standard. This work provides a novel SiO2-based encapsulation approach to solve the intrinsic instability issues of CsPbBr3 QDs, which has a profound impact on their practical applications.
关键词： photoluminescence quantum yield,CsPbBr3 quantum dots,dual-shell hollow silica spheres,stability,white light-emitting diodes
更新于2025-09-23 15:21:01
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High performance CsPbBr <sub/>3</sub> quantum dots photodetectors by using zinc oxide nanorods arrays as an electron-transport layer
摘要： The electron transport layer (ETL) in perovskite photodetectors is playing a vital role in highly efficient electron extraction. Herein, this work reports a perovskite photodetector based on hydrothermal-fabricated ZnO nanorods (NRs) as the ETL and hot-injection-fabricated CsPbBr3 quantum dot (QD) as the photoabsorber. The crystalline structure, morphologies, and photoluminescence (PL) of the materials and the physics mechanism of highly efficient electron extraction in the devices are characterized and analyzed. The PL and time-resolved PL confirm the reduced recombination and enhanced electron transport to the indium tin oxide anode. The photodetectors based on ZnO NRs/CsPbBr3 QDs exhibit enormous enhancement in the response parameters such as a rise time of 12 ms, a decay time of 38 ms, and an on/off ratio of 3000, compared with the photodetectors based on ZnO films/CsPbBr3 QDs. These results indicate that the fabricated ZnO NRs/CsPbBr3 QDs heterojunction has a wide prospect of future applications in photodetectors.
关键词： electron transport layer,photoluminescence,ZnO nanorods,perovskite photodetectors,CsPbBr3 quantum dots
更新于2025-09-23 15:19:57
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Diammonium Porphyrin-induced CsPbBr3 Nanocrystals to Stabilize Perovskite Film for Efficient and Stable Solar Cells
摘要： Employing all-inorganic perovskite quantum dots (QDs) to treat the organic-inorganic perovskite film has well-documented as a serviceable tactics to improve the performance of perovskite solar cells (PSCs). Whereas the inert molecules-coated QDs with zero dimension (0D) structure would limit further enhancement of the efficiency and stability of PSCs. Here we employ a conductive diammonium porphyrin (ZnPy-NH3Br) to treat CsPbBr3 QDs coated on 3D perovskite film, thus constructing a stable 0D-2D perovskite capping layer. The generation of large-scale nanocube crystals by treating CsPbBr3 nanocrystallites with ZnPy-NH3Br in solution demonstrates such an assembly strategy. The formed capping layer can achieve efficient charge transport and separation. As a consequence, the best efficiency of optimized device is up to 20.0%, which is superior to the control PSCs fabricated without modification (19.1%) and with pure CsPbBr3 QDs modification (19.5%). More importantly, the porphyrin-treated CsPbBr3 QDs based devices retain over 65% or 85% of their initial efficiency when placed at 85 °C or 45% humidity tracking for 1000 h, respectively. And also, with the QDs-Por incorporated, the device retained 85% of the original efficiency when illuminated at the AM 1.5 G for 450 h. Therefore, this work offered a facile avenue to modify perovskite film for fabricating the highly efficient and stable PSCs.
关键词： Perovskite solar cells,CsPbBr3 quantum dots,Protective layer,Ligand exchange,Porphyrins
更新于2025-09-23 15:19:57
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Cesium Lead Bromide Quantum Dot Light-Emitting Field-Effect Transistors
摘要： Solution processible perovskite quantum dots are considered as promising optical materials for light emitting optoelectronics. The light-emitting field-effect transistors that can be operated under relatively lower potential with an efficient energy conversion efficiency have yet to be realized with the perovskite quantum dot. Here, we present the CsPbBr3 quantum dot-based light-emitting field-effect transistor (LEFET). Surprisingly, unipolar transport characteristics with strong electroluminescence was observed at the interface of the CsPbBr3 QD-LEFET along with the exceptionally wide recombination zone of 80 μm, an order of magnitude larger than that of organic/polymer light-emitting field-effect transistors. Based on the systematic analysis for the electroluminescence of the CsPbBr3 NC-LEFET, we revealed that the increased diffusion length determined by the majority carrier mobility and the lifetime well explains the remarkably wide recombination zone. Furthermore, it was found that the energy-level matching and transport geometry of the hetero-structure also determine the charge distribution and recombination, substantially affecting the performance of the CsPbBr3 QD LEFET.
关键词： Organic/inorganic hybrid field-effect-transistor,Light emitting field-effect-transistor,Wide recombination zone,Diffusion length,CsPbBr3 quantum dots
更新于2025-09-23 15:19:57
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Amplified spontaneous emission and random lasing using CsPbBr3 quantum dots glass through controlling crystallization
摘要： By increasing the heat treatment temperature, the average size of CsPbBr3 quantum dots (QDs) in the glass matrix was increased, which contribute to the 5.5 folds increase of the optical gain coefficients. And the corresponding lasing threshold can decrease from 0.752 mJ/cm2 to 0.138 mJ/cm2.
关键词： CsPbBr3 quantum dots,glass matrix,heat treatment temperature,optical gain coefficients,lasing threshold
更新于2025-09-19 17:13:59
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Enhancing effects of reduced graphene oxide on photoluminescence of CsPbBr <sub/>3</sub> perovskite quantum dots
摘要： The composites of CsPbBr3 perovskite quantum dots (PeQDs) and reduced graphene oxide (RGO) nanosheets have been synthesized by an in-situ solution reaction. The amount of RGO can significantly affect the photoluminescence of PeQDs. Varying with the amount of RGO, the photoluminescence quantum yield can be tuned from 48.4% to 69.3%. PL decay analysis indicates that the radiative decay rate and charge transfer become faster with increasing the amount of RGO. The ellipsomitric data can be described by a double Lorentz oscillator model. The comparison between bare and composite samples indicates that the complex refractive index can be affected by RGO composite. Numerical simulations on the electric field distribution for PeQD/RGO show that the local electric field around CsPbBr3 QDs is increased by surface plasmon resonance on the surface of RGO nanosheet. These results suggest that PeQD/RGO composite can be used for highly efficient light emitting devices.
关键词： FDTD,Surface plasmon resonance,Photoluminescence,Reduced graphene oxide,CsPbBr3 quantum dots
更新于2025-09-19 17:13:59
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All-Perovskite Photodetector with Fast Response
摘要： Perovskites have attracted substantial attention on account of their excellent physical properties and simple preparation process. Here we demonstrated an improved photodetector based on solution-processing organic-inorganic hybrid perovskite CH3NH3PbI3?xClx layer decorated with CsPbBr3 perovskite quantum dots. The CH3NH3PbI3?xClx-CsPbBr3 photodetector was operated in a visible light region, which appeared high responsivity (R = 0.39 A/W), detectivity (D* = 5.43 × 109 Jones), carrier mobility (μp = 172 cm2 V?1 s?1 and μn = 216 cm2 V?1 s?1), and fast response (rise time 121 μs and fall time 107 μs). The CH3NH3PbI3?xClx-CsPbBr3 heterostructure is anticipated to find comprehensive applications in future high-performance photoelectronic devices.
关键词： Perovskite,Fast response,CsPbBr3 quantum dots,Photodetector
更新于2025-09-19 17:13:59
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CsPbBr <sub/>3</sub> Quantum Dots as Artificial Antennas to Enhance the Light-Harvesting Efficiency and Photoresponse of Zinc Porphyrin
摘要： Broadening the spectral range and enhancing the efficiency of light-harvesting materials are important to the design of novel optoelectronic devices. In this work, CsPbBr3 quantum dots (QDs) are introduced as artificial antennas to enhance both the light-harvesting efficiency and photoresponse of zinc porphyrin (ZnP). The Fluorescence Resonance Energy Transfer (FRET) process both in solution and films from the donor CsPbBr3 QD to the acceptor ZnP have been systematically investigated, and an energy transfer efficiency over 70% in solution and a high optical sensitivity have been realized with the optimal of QD/ZnP ratio on films. A photocurrent density of up to 1.00×10-4 A·cm-2 can be achieved for the QD/ZnP film, and the corresponding on/off photocurrent value can be increased by two orders of magnitude compared with that of ZnP. Furthermore, the as-prepared light-harvesting film also demonstrates a high optical sensitivity at the optimal QD/ZnP ratio. Our research provides an effective way for designing and improving the QD/ZnP “antenna” for solar-energy harvesting devices.
关键词： Zinc Porphyrin,CsPbBr3 Quantum Dots,FRET,Photoresponse,Light-Harvesting Efficiency
更新于2025-09-19 17:13:59
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Evidence for Ferroelectricity of All-Inorganic Perovskite CsPbBr3 Quantum Dots
摘要： The ferroelectric-optical combination of properties in halide perovskites has attracted tremendous interests because of its potential for optoelectronic and energy applications. However, very few reports focus on the ferroelectricity of all-inorganic halide perovskites quantum dots. Herein, we report a excellent ferroelectricity in CsPbBr3 quantum dots (QDs) with a saturation polarization of 0.25 μC/cm2. Differential scanning calorimeter (DSC), X-ray diffraction (XRD), transmission electronic microscopy (TEM) revealed that the mechanism of ferroelectric-paraelectric switching of CsPbBr3 QDs can be attributed to the phase transition from cubic phase (????3??) to orthorhombic phase (Pna21). In the orthorhombic CsPbBr3, the distortion of octahedral [PbBr6]4- structural units and the off-center Cs+ generated the slightly separated centres of positive charge and negative charge, resulting in the ferroelectric properties. The variable temperature emission spectrum from 328 K to 78 K exhibits green luminescence and the gradually red shift due to the phase transition. This finding opens up a avenue to explore the ferroelectric-optical properties of inorganolead halide perovskites for high-performance multifunctional materials.
关键词： CsPbBr3 quantum dots,all-inorganic perovskite,phase transition,optoelectronic applications,ferroelectricity
更新于2025-09-16 10:30:52
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Precipitating CsPbBr <sub/>3</sub> quantum dots in boro-germanate glass with a dense structure and inert environment toward highly stable and efficient narrow-band green emitters for wide-color-gamut liquid crystal displays
摘要： All-inorganic perovskite CsPbBr3 quantum dots (QDs) are becoming the most popular narrow-band green emitter for use as a critical material in next generation wide-color-gamut backlight displays. However, their intrinsic poor stability greatly hinders their development for practical applications. Herein, CsPbBr3 QDs were successfully precipitated in boro-germanate glass (CsPbBr3 QDs@glass) with well-designed compositions, not only retaining a high photoluminescence quantum yield (PLQY of 43% upon 450 nm excitation) and narrow bandwidth (FWHM of 22 nm), but also showing significantly enhanced stability in relation to water, heat, and UV/blue irradiation. The relative PL intensity of CsPbBr3 QDs@glass was maintained at 60% or 85% after being immersed in water for 22 days or exposed to UV light for 100 hours, respectively. Moreover, CsPbBr3 QDs@glass samples present impressive recovery abilities in thermal cycling experiments or upon intermittent blue light irradiation. Finally, an all-inorganic white light-emitting diode (white LED) achieving 125% of National Television Standards Committee (NTSC) performance was fabricated through employing green-emitting CsPbBr3 QDs@glass and red-emitting Cs2SiF6:Mn4+ phosphor-in-glass (PiG) plates as color convertors. The design rules established here could initiate the further exploration of other glass systems with moderate halide solubilities and low melting temperatures to precipitate highly e?cient and stable CsPbX3 (X = Cl, Br, I) QDs.
关键词： stability,boro-germanate glass,CsPbBr3 quantum dots,wide-color-gamut liquid crystal displays,narrow-band green emitters
更新于2025-09-12 10:27:22