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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 Engineering of Alla??Inorganic Perovskite Quantum Dots with Quasi Corea??Shell Technique for Higha??Performance Photodetectors
摘要： All-inorganic lead halide perovskites with good surface morphology show substantial prospect for optoelectronic devices. However, the anion exchange of coordinated alkylamine ligands (e.g., oleic acid and oleylamine) can detach ligands and induce more interface trap sites, subsequently to reduce device performance. In this paper, therefore, a simple solution-processed route is presented to synthesize quasi coreshell CsPbBr3formamidinium iodide (FAI = CH(NH2)2I) colloidal quantum dots (CQDs), and then it is applied as the active layer for photodetectors by finely controlling the ligands exchange. The presence of FAI = CH(NH2)2I on CsPbBr3 is confirmed by Fourier transform infrared spectroscopy. As a result, the photodetector ITO/ZnO (100 nm)/CsPbBr3 (150 nm)/Au show an enhanced specific detectivity over 1013 Jones with a responsivity of 19 A W1 under 3 mW cm2 405 nm illumination at 1.5 V. The experimental data show that the enhanced device performance is due to the improved crystallinity and less surface defects of CsPbBr3 CQDs, as the result of less alkylamine ligands is detached during its FAI passivation, thus the charge carriers’ mobility of the film is improved. Therefore, it provides a promising way for high-performance solution-processed all-inorganic CsPbBr3 based optoelectronic devices.
关键词： CsPbBr3 perovskite nanocrystals,solution-processed,surface passivation,recombination process
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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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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Solutiona??Processed Higha??Quality Cesium Lead Bromine Perovskite Photodetectors with High Detectivity for Application in Visible Light Communication
摘要： Cesium lead bromide (CsPbBr3) perovskite photodetectors (PDs) are attractive for applications in visible light communication (VLC) due to ultra-high detectivity and fast response speed. However, the fabrication of high-quality CsPbBr3 polycrystalline films using solution-based process is very challenging. Due to the low solubility of CsBr in precursor solutions, solution-processed CsPbBr3 films are typically discontinuous and porous, hindering the performance of resulting PDs. Herein, a facile and modified sequential spin-coating method is introduced to prepare high-crystallinity, pinhole-free CsPb2Br5-CsPbBr3 perovskite films with an average grain size of ≈1 μm. The hole-transport-layer-free (HTL-free) PDs based on the CsPb2Br5-CsPbBr3 perovskite films show high performance parameters, including the responsivity of 0.11 A W?1, the detectivity of 1.4 × 1012 Jones, a linear dynamic range of 128.6, and an on/off ratio of 1.5 × 106. The PDs outperform other HTL-free perovskite PDs and are comparable to the p–i–n perovskite PDs reported in the literature. In addition, the high-performance CsPb2Br5-CsPbBr3 PDs are applied in VLC by using the PD as a self-powered signal receiver of voice commands in a simulated room. This work uniquely combines the features of high-performance self-powered perovskite PDs with VLC techniques, paving the path to wide applications of all-inorganic perovskite PDs.
关键词： CsPb2Br5-CsPbBr3,perovskites,self-powered photodetectors,visible light communication
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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Enhancement of Photoluminescence Quantum Yield and Stability in CsPbBr3 Perovskite Quantum Dots by Trivalent Doping
摘要： We determine the influence of substitutional defects on perovskite quantum dots through experimental and theoretical investigations. Substitutional defects were introduced by trivalent dopants (In, Sb, and Bi) in CsPbBr3 by ligand-assisted reprecipitation. We show that the photoluminescence (PL) emission peak shifts toward shorter wavelengths when doping concentrations are increased. Trivalent metal-doped CsPbBr3 enhanced the PL quantum yield (~10%) and air stability (over 10 days). Our findings provide new insights into the influence of substitutional defects on substituted CsPbBr3 that underpin their physical properties.
关键词： ligand-assisted reprecipitation,trivalent doping,nanocrystals,perovskite,CsPbBr3
更新于2025-09-23 15:19:57
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Blue-emitting and self-assembled thinner perovskite CsPbBr <sub/>3</sub> nanoplates: Synthesis and formation mechanism
摘要： Low dimensional semiconductor nanomaterials have a great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr3 perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr3 NPls, self-assembled to a face-to-face stacked state, had a thickness of 4.4 nm (equal to only 2 monolayers, 2 MLs) and showed a maximum emission at 437 nm and a narrow FWHM of 14 nm. The formation mechanism of the CsPbBr3 NPls by adding FeBr3 was ascribed to the constrained growth of CsPbBr3 nanocubes when the surface of Cs+ ions was substituted by the protonated oleylammonium from the byproduct OLA-HBr.
关键词： blue-emitting,quantum confinement,self-assembly,CsPbBr3,perovskite nanoplates
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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Novel antisolvent-washing strategy for highly efficient carbon-based planar CsPbBr3 perovskite solar cells
摘要： All-inorganic CsPbBr3 is attracting tremendous attentions in photovoltaic field due to its superior stability. However, CsPbBr3 perovskite always suffers from a poor crystallinity and film morphology. Many efforts have been paid on the CsBr deposition process to improve the film quality, while few attentions are paid on the crystallization kinetics of the PbBr2 framework film. Here, we demonstrate a novel antisolvent-washing strategy for the PbBr2 film for the first time to fabricate high-quality CsPbBr3 film. This technique has a significant impact on the nucleation and growth of PbBr2 crystals. As-prepared CsPbBr3 films exhibit more homogeneous with higher crystallinity and coverage as well as larger grain sizes compared to those untreated ones. The best-performing antisolvent-treated perovskite solar cell achieves a scanned power conversion efficiency of 8.55%, which is an excellent efficiency for planar CsPbBr3 cells reported yet. This enhancement can be mainly attributed to the more effective charge transport and suppressed non-radiative recombination caused by the reduced defect densities. Moreover, our devices show superb stability when stored in air for 1000 h and upon persistent thermal attack at 80°C. Our work provides a new train of thought for controlling the growth dynamics and film morphology of CsPbBr3 films.
关键词： Antisolvent-washing,CsPbBr3,Planar heterojunction,High efficiency and stability,Carbon-based,Low costs
更新于2025-09-19 17:13:59