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Room temperature synthesis of stable single silica-coated CsPbBr3 quantum dots combining tunable red emission of Ag–In–Zn–S for High-CRI white light-emitting diodes
摘要： White light emitting diodes (WLEDs) based on all-inorganic halide (CsPbX3, X ? Cl, Br and I) perovskite quantum dots (QDs) have attracted broad attention due to their high brightness. However, their poor stability and anion-exchange reaction when utilized together are still the main challenges that impede their applications. Herein, a one-step in situ method under room temperature in air is proposed to synthesize CsPbBr3 QDs coated with SiO2 (CsPbBr3@SiO2), where the whole process takes only 20 s. The as-prepared CsPbBr3@SiO2 QDs samples present an enhanced stability in the thermal and polar-solvent environment, maintaining its high photoluminescence quantum yield (PLQY~75%). Thereby WLEDs are constructed by combining CsPbBr3@SiO2 with red Ag–In–Zn–S QDs on InGaN blue chip, achieving a high color rendering index (CRI) of 91, a correlated color temperature (CCT) of 3689 K and a power efficiency of 40.6 lm W?1.
关键词： WLEDs,Ag–In–Zn–S QDs,Stability,CsPbBr3 QDs
更新于2025-11-14 15:32:45
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Enhanced UV-visible detection of InGaZnO phototransistors via CsPbBr3 quantum dots
摘要： Indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) exhibit high field-effect carrier mobility and low off-state current, which are attractive for high speed and low noise photodetectors and image sensor applications. However, with an optical band gap of ~3.3 eV, the photodetection range of IGZO TFTs is limited to short wavelength ultraviolet (UV) light. Here, we demonstrate a simple approach to enhance the performance of IGZO-based phototransistors by incorporating layers of solution-processed perovskite quantum dots (QDs) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Owing to the fast transfer of photogenerated electrons by CsPbBr3 QDs absorbing layer, the photoresponse of QD-decorated IGZO phototransistor is extended to the visible range (500 nm), and the responsivity and detectivity of QD-decorated device are more than two order higher than those of original IGZO TFTs. Moreover, the QD-decorated IGZO phototransistor also exhibits enhanced performance under UV light (350 nm), achieving a responsivity of 9.72 A/W, a detectivity of 2.96 × 1012 Jones, and a light to dark current ratio in the order of 106 at a wavelength of 350 nm (a light intensity of 207.3 μW/cm2).
关键词： heterojunction,CsPbBr3 QDs,IGZO,phototransistors
更新于2025-09-23 15:19:57
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Down-Shifting and Anti-Reflection Effect of CsPbBr3 Quantum Dots/Multicrystalline Silicon Hybrid Structures for Enhanced Photovoltaic Properties
摘要： Over the past couple of decades, extensive research has been conducted on silicon (Si) based solar cells, whose power conversion e?ciency (PCE) still has limitations because of a mismatched solar spectrum. Recently, a down-shifting e?ect has provided a new way to improve cell performances by converting ultraviolet (UV) photons to visible light. In this work, caesium lead bromide perovskite quantum dots (CsPbBr3 QDs) are synthesized with a uniform size of 10 nm. Exhibiting strong absorption of near UV light and intense photoluminescence (PL) peak at 515 nm, CsPbBr3 QDs show a potential application of the down-shifting e?ect. CsPbBr3 QDs/multicrystalline silicon (mc-Si) hybrid structured solar cells are fabricated and systematically studied. Compared with mc-Si solar cells, CsPbBr3 QDs/mc-Si solar cells have obvious improvement in external quantum e?ciency (EQE) within the wavelength ranges of both 300 to 500 nm and 700 to 1100 nm, which can be attributed to the down-shifting e?ect and the anti-re?ection property of CsPbBr3 QDs through the formation of CsPbBr3 QDs/mc-Si structures. Furthermore, a detailed discussion of contact resistance and interface defects is provided. As a result, the coated CsPbBr3 QDs are optimized to be two layers and the solar cell exhibits a highest PCE of 14.52%.
关键词： down-shifting e?ect,solar cell,anti-re?ection property,caesium lead bromide perovskite quantum dots (CsPbBr3 QDs),multicrystalline Si (mc-Si)
更新于2025-09-23 15:19:57
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Surface polarity engineering of ZnO layer for improved photoluminescence of CsPbBr3 quantum dot films
摘要： The surface polarity of nanocrystalline ZnO film, a typical electron transport material in optoelectronics, is chemically modified using self-assembled monolayer (SAM) of phenethyl trichlorosilane (PETS). The surface treatment is proved to generate a hydrophobic surface by removing the hydroxyl groups on the oxide layer, which reduces the emission quenching of the subsequent CsPbBr3 quantum dot film. In addition, the surface polarity was engineered with varying PETS concentration, thereby contribute to an increased photoluminescence quantum yield (PLQY) by up to 50%. Meanwhile, the thermal stability of photoluminescence was enhanced showing a wide-range temperature tolerance up to 140 ℃.
关键词： SAM,Stability,Surface Polarity,PETS,ZnO,CsPbBr3 QDs
更新于2025-09-23 15:19:57
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Enhanced photocatalytic activity of Ag-CsPbBr3/CN composite for broad spectrum photocatalytic degradation of cephalosporin antibiotics 7-ACA
摘要： A visible-light-induced antibiotics degradation system based on a nano-Ag, CsPbBr3 quantum dot (QDs) and bulk g-C3N4 (CN) ternary assembly (Ag-CsPbBr3/CN) has been firstly constructed under an organic phase environment, oleylamine (OLA) and oleic acid (OA) were used as surfactants to stabilize the CsPbBr3, L-cysteine was used to facilitate the interaction between nano-Ag, CsPbBr3 and CN. The new ternary assembly of Ag-CsPbBr3/CN composite was used to degrade 7-aminocephalosporanic acid (7-ACA) under visible light irradiation, and the 7%-Ag-CsPbBr3/CN composite displayed the superior photocatalytic activity, approximately 92.79% of 7-ACA has been degraded to CO2, H2O and other small molecules at 140 min, which was approximately 1.49-folds, 1.56-folds, 3.01-folds and 11.43-folds higher than 9%-CsPbBr3/CN, 7%-Ag/CN, pure CN and pure CsPbBr3, respectively. A possible mechanism for 7-ACA degradation over Ag-CsPbBr3/CN composite were proposed according to detailed measurements of adsorption test, Brunauer-Emmett-Teller (BET) measurement, UV-vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL), transient photocurrent response and electrochemical impedance spectroscopy (EIS) measurement, and the enhanced photocatalytic activity of Ag-CsPbBr3/CN composite could be attributed to the excellent adsorbability, the enhanced light-harvesting and reduced charge recombination, as well as the synergistic effects of nano-Ag and CsPbBr3 co-loaded with CN. In addition, Holes (h+) and hydroxyl radicals (·OH) played major roles, electronic (e-) and superoxide radical (·O2-) played minor roles based on the reactive-species-trapping experiments, the NBT transformation and the 7-hydroxycoumarin fluorescent experiments. Furthermore, a possible 7-ACA degradation pathway was investigated based on the Liquid Chromatography-Mass spectroscopy (LC-MS) experiment to better understand the degradation process. The present opens up a new insight for using CsPbBr3 as photocatalyst to degrade antibiotics.
关键词： CsPbBr3 QDs,Nano Ag,7-aminocephalosporanic acid.,Degradation,Bulk g-C3N4
更新于2025-09-19 17:15:36
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p-GaN/n-ZnO Nanoplate/CsPbBr3 Quantum Dots Heterojunction Light-Emitting Diode for Dual-Wavelength Emission
摘要： In this paper, we report a p-GaN/n-ZnO nanoplate/CsPbBr3 quantum dots (QDs) heterojunction light-emitting diode (LED) for dual-wavelength emission. ZnO nanoplates were prepared by vapor phase transport on the GaN thin film to form the p-GaN/n-ZnO nanoplate heterojunction. Afterwards, green CsPbBr3 QDs (band gap of 2.25 eV) were deposited on ZnO nanoplates to realize green light emission. The structure and photoluminescence of the ZnO nanoplates and CsPbBr3 QDs were characterized. The as-prepared LED device with turn-on voltage of ~ 2.7 V displays a typical rectification behavior. The electroluminescence spectra with narrow emission peaks reveal the device presents commendable dual-wavelength electroluminescence performance at ~ 385 nm and ~ 512 nm and the electroluminescence intensity saturates at about 65 mA/cm2. Moreover, the detailed electroluminescence mechanism including emission originate of n-ZnO/p-GaN heterojunction was discussed based on the band diagram. Thus, our work indicates compelling potential for the practical application of perovskite LEDs.
关键词： CsPbBr3 QDs,Light emitting diode,electroluminescence,ZnO nanoplate
更新于2025-09-16 10:30:52
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CsPbBr3 quantum dots assisted crystallization of solution-processed perovskite films with preferential orientation for high performance perovskite solar cells
摘要： The performance of hybrid perovskite solar cells (PSCs) is significantly influenced by the crystallization and morphology of perovskite films. Herein, a novel method of CsPbBr3 quantum dots (QDs) assisted nucleation is applied to prepare high quality solution-processed methylammonium lead iodide (MAPbI3) films by employing CsPbBr3 QDs as an additive into diethyl ether anti-solvent. The appropriate amount of CsPbBr3 QDs can act as effective heterogeneous nucleation centers, leading to the formation of smooth and pinhole-free perovskite films with increased grain size. Furthermore, the growth direction of MAPbI3 grains is regulated by CsPbBr3 QDs, exhibiting preferential orientation of (110) plane. Therefore, the MAPbI3 films with CsPbBr3 QDs modification show reduced defects and increased carrier lifetime. As a result, the champion PSC with a maximum power conversion efficiency (PCE) up to 20.17% is achieved and 85% of its initial PCE is maintained after aging 1000 hours at room temperature under a relative humidity of 50%. This work demonstrates a feasible way to prepare high quality perovskite films for optoelectronic applications.
关键词： preferred orientation,heterogeneous nucleation centers,perovskite solar cells,CsPbBr3 QDs
更新于2025-09-12 10:27:22
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Analysis of aqueous systems using all-inorganic perovskite CsPbBr3 quantum dots with stable electrochemiluminescence performance using a closed bipolar electrode
摘要： All-inorganic perovskite CsPbX3 (X = Cl, Br, I) quantum dots (QDs) have emerged as a new class of semiconductor nanocrystals, but the stability of CsPbX3 QDs in polar solvents is still a significant challenge. Since most targets in analytical chemistry, especially for biological detection, exist in an aqueous medium, this weakness seriously hampers practical analytical applications of CsPbX3 QDs. In this work, we introduce a closed bipolar electrode (BPE) to extend the application of perovskite QDs to aqueous systems. Based on the principle of conservation of charge in the electrode reactions at opposite ends of the BPE, the concentration of H2O2 in an aqueous medium can be detected by measuring the ECL intensity of CsPbBr3 QDs in an organic solution. Thus, for the first time, H2O2 in an aqueous system has been successfully analyzed using all-inorganic perovskite CsPbBr3 QDs with stable electrochemiluminescence performance combined with a closed bipolar electrode chip.
关键词： Bipolar electrode,Electrochemiluminescence,Perovskite,CsPbBr3 QDs
更新于2025-09-11 14:15:04