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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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Sequentially vacuum evaporated high-quality CsPbBr3 films for efficient carbon-based planar heterojunction perovskite solar cells
摘要： All-inorganic CsPbBr3 perovskite has triggered great interests in photovoltaic field owing to its superior stability. However, the uncontrollable CsPbBr3 film growth in solution always leads to a poor film quality with low phase-purity as well as many surface and bulk defects. Herein, we demonstrate an environmentally friendly non-solution route to fabricate high-quality CsPbBr3 films for carbon-based planar perovskite solar cells. By precisely tuning the thickness ratio of the evaporated CsBr to PbBr2 precursors (r), the dominant phase conversion of the cesium lead bromide perovskites from PbBr2-rich CsPb2Br5 (r ? 12:7) to CsPbBr3 (r ? 12:8), and further to CsBr-rich Cs4PbBr6 (r ? 12:9) are achieved. The optimized CsPbBr3 perovskites are highly phase-pure and crystallized with ultra-high light absorption ability. The as-prepared CsPbBr3 films also exhibit a dense and uniform morphology with large grain sizes and monolayer-vertical aligned grains. The corresponding devices deliver a champion PCE of 7.58%, which is an excellent efficiency among carbon-based CsPbBr3 cells with evaporated CsPbBr3 light absorbers. The large-area (1 cm2) devices also achieve an efficiency of 6.21%. Moreover, the unencapsulated CsPbBr3 devices present superior moisture and thermal stabilities. Our work provides a facile approach to fabricate high-quality and large-area CsPbBr3 films for highly efficient solar cells, light-emitting diodes and photodetectors.
关键词： CsPbBr3,Highly efficient and stable,Non-solution,Sequential evaporation,Perovskite solar cells,Carbon-based
更新于2025-09-19 17:13:59
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Self-assembled template-confined growth of ultrathin CsPbBr3 nanowires
摘要： Fabrication of ultrathin (e.g., ～2 nm) CsPbBr3 nanowires is still challenging for existing methods, for the extremely fast crystal growth process of CsPbBr3. Here, we developed a self-assembled nanotemplate-confined growth concept to prepare ultrathin CsPbBr3 nanowires. During electrospinning using the N,N-dimethylformamide (DMF) solution composed of polymethyl methacrylate (PMMA), PbBr2, CsBr, and capping agents, PMMA chains would assemble into nanochannels acting as nanotemplates within the electrospun PMMA fibers. Owing to the very limited amount of precursors within the nanochannels, ultrathin CsPbBr3 nanowires were prepared after DMF evaporation. The CsPbBr3 nanowires within the PMMA fibers or dispersed in toluene showed bright blue luminescence. The structure of the CsPbBr3 products could be adjusted by the stirring time, as well as the amount of PMMA, PbBr2, and CsBr in DMF. Overall, we developed a new method towards engineering ultrafine CsPbBr3 nanostructure through self-assembled template-confined growth concept during electrospinning, which may find potential applications in blue light emitting diodes and other optoelectronic devices.
关键词： Nanowires,CsPbBr3,Electrospinning,Photoluminescence
更新于2025-09-19 17:13:59
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High staility of silica-wrapped CsPbBr3 perovskite quantum dots for light emitting application
摘要： Encapsulating quantum dots (QDs) into other medium has been considered as an efficacious method to avoid the fluorescence degradation of QDs. Here, we proposed a facile method to embed CsPbBr3 perovskite QDs in silica matrix derived from (3-aminopropyl)triethoxysilane (APTES) at room temperature in open air. The QDs/SiO2 composite was extracted from the sol-gel solution by using a precipitation-encapsulation method assisted with APTES. As-prepared composite powder possess a high photoluminescence quantum yield (PLQY) of 68% and a full width at half maximum (FWHM) of ~23 nm. The QDs/SiO2 compounds show excellent stability after the five heating cycles (105 °C) and a continuous xenon irradiation (500 W, 70 °C). Besides, the products remain 94.3% and 98.6% photoluminescence (PL) intensity after 30 days of storage (25 °C) and 96 hours of ultraviolet (UV) irradiation (λ= 365 nm) respectively. The white light-emitting diode (LED) was fabricated by coating green-emitting CsPbBr3@SiO2 composite powder and commercial red phosphors on blue chip. The fabricated white LED performed excellent light characteristics with a luminous efficacy (ηL) of 58.9 lmW-1 and a correlated color temperature (CCT, Tc) of 5829 K (current = 20 mA), it also display a wide color gamut with 126.8% of National Television System Committee (NTSC) color triangle area.
关键词： white LED,stability,perovskite QDs,CsPbBr3,SiO2
更新于2025-09-19 17:13:59
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High-speed colour-converting photodetector with all-inorganic CsPbBr3 perovskite nanocrystals for ultraviolet light communication
摘要： Optical wireless communication (OWC) using the ultra-broad spectrum of the visible-to-ultraviolet (UV) wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency (RF) communication. However, the lack of an efficient UV photodetection methodology hinders the development of UV-based communication. The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors, which offer low-cost and mature platforms. To address this technology gap, we report a hybrid Si-based photodetection scheme by incorporating CsPbBr3 perovskite nanocrystals (NCs) with a high photoluminescence quantum yield (PLQY) and a fast photoluminescence (PL) decay time as a UV-to-visible colour-converting layer for high-speed solar-blind UV communication. The facile formation of drop-cast CsPbBr3 perovskite NCs leads to a high PLQY of up to ~73% and strong absorption in the UV region. With the addition of the NC layer, a nearly threefold improvement in the responsivity and an increase of ~25% in the external quantum efficiency (EQE) of the solar-blind region compared to a commercial silicon-based photodetector were observed. Moreover, time-resolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source, thus elucidating the potential of this layer as a fast colour-converting layer. A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr3–silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode (LED). These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.
关键词： CsPbBr3 perovskite nanocrystals,Silicon-based photodetector,UV photodetection,Solar-blind UV communication,Optical wireless communication
更新于2025-09-19 17:13:59
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All Green Solvents for Fabrication of CsPbBr <sub/>3</sub> Films for Efficient Solar Cells Guided by the Hansen Solubility Theory
摘要： Toxic solvents used in the fabrication of perovskite solar cells are an obstacle for their commercialization. Replacing those toxic solvents with green solvents is very important for both ecological environment safety and the health of operators working in manufactory and labs. CsPbBr3-based solar cells have attracted increasing attention due to its high stability. Herein, high-quality CsPbBr3 films are prepared using all green solvents based on a two-step spin-coating method. In the first step, a green solvent system of polyethylene glycol (PEG) with the addition of γ-butyrolactone is used for preparing PbBr2 solutions by matching the Hansen solubility parameters (HSPs) between PbBr2 and the mixed solvent system. By optimizing the HSPs and viscosity, a new complex of PbBr2·(PEG) is formed by spin-coating from the PbBr2 solution, followed by acetic acid dropping while spinning. In the second step, green water is used to dissolve CsBr to prepare a high concentration CsBr/H2O solution. High-quality CsPbBr3 films with full coverage are obtained by spin-coating CsBr/H2O solution onto the PbBr2·(PEG) films after annealing. As a result, a solar cell with configuration of fluorine-doped tin oxide/TiO2/CsPbBr3/carbon exhibits a power conversion efficiency of 8.11% due to its high-quality harvest layer.
关键词： perovskite solar cells,green solvents,Hansen solubility parameters,CsPbBr3,toxicity
更新于2025-09-19 17:13:59
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Improving the Performance and Stability of Perovskite Light-Emitting Diodes by a Polymeric Nanothick Interlayer-Assisted Grain Control Process
摘要： CsPbBr3 is a promising light-emitting material due to its wet solution processability, high photoluminescence quantum yield (PLQY), narrow color spectrum, and cost-effectiveness. Despite such advantages, the morphological defects, unsatisfactory carrier injection, and stability issues retard its widespread applications in light-emitting devices (LEDs). In this work, we demonstrated a facile and cost-effective method to improve the morphology, efficiency, and stability of the CsPbBr3 emissive layer using a dual polymeric encapsulation governed by an interface-assisted grain control process (IAGCP). An eco-friendly low-cost hydrophilic polymer poly(vinylpyrrolidone) (PVP) was blended into the CsPbBr3 precursor solution, which endows the prepared film with a better surface coverage with a smoothened surface. Furthermore, the poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/emissive layer interface further promotes the film quality and the performance of the derived LED. It is mainly attributed to three major consequences: (i) reduced grain size of the emissive layer, which facilitates charge recombination, (ii) reduced current leakage due to the enhanced electron-blocking effect, and (iii) improved color purity and air stability owing to better defect passivation. As a result, the optimized composite emissive film can retain the luminescence properties even on exposure to ambient conditions for 80 days and ～62% of its initial PL intensity can be preserved after 30 days of storage without any encapsulation.
关键词： efficiency,light-emitting diodes,polymeric nanothick interlayer,grain control process,CsPbBr3,stability
更新于2025-09-19 17:13:59
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Enhanced charge extraction in carbon-based all-inorganic CsPbBr3 perovskite solar cells by dual-function interface engineering
摘要： Carbon-based all-inorganic CsPbBr3 perovskite solar cells (PSCs) have attracted growing interests due to low cost and excellent tolerances toward moisture, temperature, oxygen and ultraviolet light. However, carrier recombination of CsPbBr3 film and large energy level differences at CsPbBr3/carbon interface are still the most crucial problem for further enhancement of power conversion efficiency. In the current study, an intermediate energy level at CsPbBr3/carbon interface and CsPbBr3 film passivation are employed by coating hexane solution of CsPbBrxI3-x nanocrystals (NCs) on the perovskite layer. Through systematic study on interfacial engineering, it is found that CsPbBrxI3-x NCs with tunable energy level can remarkably reduce energy loss and hexane under passivation treatment can enlarge perovskite grain size as well as reduce trap state density. A champion power conversion efficiency of 9.45% is achieved for CsPbI3 NCs tailored all-inorganic CsPbBr3 PSC in comparison with 5.26% for NCs-free device, with the unencapsulated carbon-based CsPbBr3 PSC exhibiting remarkable long-term stability over 900 h in 80% relative humidity air atmosphere at 25 °C. This work provides an effective approach to promote charge extraction and reduce defect states density as well as enhance the performance of PSCs.
关键词： CsPbBrxI3-x nanocrystals,Interface engineering,Charge extraction,Solvent treatment,All-inorganic CsPbBr3 perovskite solar cells
更新于2025-09-19 17:13:59
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Efficiency Enhancement of Perovskite CsPbBr <sub/>3</sub> Quantum Dot Light-emitting Diodes by Doped Hole Transport Layer
摘要： Balanced charge injection is essential to high-performance Perovskite CsPbBr3 quantum dot-based light-emitting diodes (QLEDs). However, low mobility of hole-transport materials (HTMs) severely restrict improving performance of QLEDs. Herein, we provide a novel HTMs to improve the highest occupied molecular orbital (HOMO) energy level structure and carrier mobility by doping poly (9-vinlycarbazole) (PVK) and poly [N, N′-bis(4-butylphenyl)-N, N′-bis(phenyl) benzi-dine] (poly-TPD). We also introduce poly (methyl methacrylate) (PMMA) as electron block layer to further achieve charge injection balance. Finally, an enhanced external quantum efficiency (EQE) of 0.53% and 414.83 cd/m2 was obtained. Compared with the untreated QLED, this result has been 8-fold enhanced, provides a new approach to attain better performance.
关键词： Quantum Dot Light-emitting Diodes,Efficiency Enhancement,Perovskite CsPbBr3,Hole Transport Layer
更新于2025-09-19 17:13:59
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Nanocrystalline structure control and tunable luminescent mechanism of Eu-doped CsPbBr3 quantum dots glass for WLED
摘要： As CsPbX3(Cl, Br, I) perovskite quantum dot glass has been widely reported, the discovery of next-generation perovskite luminescent materials has been challenged by doping rare earth activators with energy-level transition. In this work, we report a novel Eu-doped quantum dots glass material with tunable luminescence properties. The structure characteristic and tunable luminescent mechanism were investigated by combining X-ray diffraction, X-ray photoelectric spectroscopy, excitation and emission spectra. It is found that Eu ions replaced the lattice of Pb in CsPbBr3 quantum dots and formed CsEuBr3 quantum dots, which result in a blue emission. Meanwhile, a green emission comes from CsPbBr3 quantum dots, and a red emission originally comes from Eu3+ in glass matrix can also be observed by controlling the heat treatment temperature. A light-emitting diode is designed based on the prepared Eu doped quantum dots glass without doping any phosphors, and a warm-light with CCT at 4075k is obtained. The present work provides a new luminescence tunable design principle of europium doped quantum dots glass materials and could bring inspiration to the future exploration of rare earth ion-doped quantum dot glass material in the future.
关键词： WLED,CsEuBr3,tunable luminescence,Eu-doped,CsPbBr3,perovskite quantum dot glass
更新于2025-09-19 17:13:59