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Exploration of polymer-assisted crystallization kinetics in CsPbBr3 all-inorganic solar cell
摘要： All-inorganic perovskite material (CsPbBr3) has attracted enormous attention in photovoltaic devices due to superior stability. However, the thickness of CsPbBr3 film beyond 100 nm suffers from poor morphology, impurity phase and defects due to unbalance between fast growth and slow nucleation of film. Here, we introduce polyethylene glycol (PEG) into solution to achieve compact CsPbBr3 film with pure phase via a simple one-step solution process. The Lewis base of PEG interacts with the Lewis acid of Pb2+ to reduce the cluster size of CsBr-PbBr2-DMSO colloids as well as to increase the nucleation rate. The CsPbBr3 film magnitude less in intrinsic defect concentration is obtained by the addition of PEG. The open-circuit voltage increases from 1.15 eV to 1.41 eV with the highest efficiency of 7.8% as a result of less charge recombination of device, which is the highest efficiency ever recorded in one step solution process. The current–voltage curves measured at five different positions of large size device based on PEG (100 mm2) were almost identical, indicating highly uniform of devices. Thanks to the high quality of PEG modified CsPbBr3 film, there is no efficiency reduction during 120 h UV illumination. It was further used as a UV filter in tandem device which effectively restricts the UV degradation of bottom organic-inorganic perovskite solar cell. The tandem solar cell still remains 93% of the initial PCE after 120 h UV aging test, which are the main routes for commercializing device.
关键词： UV stability,CsPbBr3,Crystallization kinetics,Polyethylene glycol (PEG)
更新于2025-09-12 10:27:22
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Modulation of Growth Kinetics of Vacuum-Deposited CsPbBr <sub/>3</sub> Films for Efficient Light-Emitting Diodes
摘要： Due to its excellent optical properties and good stability, all-inorganic halide perovskite CsPbX3 (X=I, Br, Cl) has been attracting interest for use in light-emitting diodes (LEDs). One challenge is improving the efficacy of the spatial confinement of excitons for higher luminescence efficiency. Here, we present a simple yet very effective strategy to form fine-grain-structured CsPbBr3 polycrystalline films prepared by thermal co-evaporation. The strategy involves controlling growth kinetics by adjusting the deposition flux which, along with growth temperature, determines the nucleation rate and therefore eventual grain structure. A correlation between deposition flux and average grain size was noted except for a very large deposition flux when there were large hillocks, which we attributed to the peculiar growth behavior of PbBr2 films. The growth conditions that produced a nano-scale grain structure and textured orientations without large hillocks also resulted in the highest luminescence efficiency as we anticipated. With the optimized CsPbBr3 light emitters, we demonstrate a green light-emitting (at 524 nm) LED with a maximum current efficiency of 1.07 cd/A and an extremely narrow electroluminescence spectrum of 18 nm, a result that highlights the potential of vacuum-processed CsPbBr3 films for high efficiency LEDs.
关键词： Light-emitting Diodes,Thermal co-evaporation,Perovskites,Vacuum deposition,LEDs,CsPbBr3
更新于2025-09-12 10:27:22
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Porous single-wall carbon nanotube templates decorated with all-inorganic perovskite nanocrystals for ultra-flexible photodetectors
摘要： As an inevitable optoelectronic material with unique properties, halide perovskites attracted increasing attention in recent years. Meanwhile, hybridization of nanostructured perovskites with one-dimensional (1D) or two-dimensional (2D) functional materials has exhibited unique applications in nanotechnology. In this communication, a highly conducting porous single-wall carbon nanotube (p-SWCNT) template decorated with phase-pure CsPbBr3 nanocrystals by simple solution-phase technique was demonstrated, and the ultra-flexible photodetector Au/p-SWCNT:CsPbBr3/Au showed high sensitivity even in highly bending state. Also, the mechanism of wetting CsPbBr3 along p-SWCNT and the detailed fabrication process for ultra-flexible photodetectors were highlighted. The direct contact (in-situ) on p-SWCNT by crystallization of perovskite precursor can enhance the charge transfer at their interface effectively. At applied bias of +5 V, the optimized photodetector Au/p-SWCNT:CsPbBr3/Au exhibits a maximum photoresponsivity of 41.0 AW-1 with a specific detectivity of 1.67×1012 Jones under an incident 232 μW/cm2 520 nm illumination. In addition, it exhibits excellent mechanical and electrical properties even under high strain (i.e. bending angle up to -17°) and recovers the original performance after repeated bending cycles upto 1000 times. Our experimental results showed that such a hybrid materials provide a promising method for rigid and flexible optoelectronic devices.
关键词： Porous single-wall carbon nanotube (p-SWCN),inorganic perovskite nanocrystals,flexible photodetector,CsPbBr3,visible light photodetector
更新于2025-09-12 10:27:22
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revealed by time-resolved photoluminescence spectroscopy
摘要： We systematically investigate the recombination mechanism of photogenerated charge carriers in bulk CsPbBr3 by means of time-resolved photoluminescence (TR-PL) spectroscopy at low temperature and various laser excitation powers. A dynamic recombination model is proposed to describe the TR-PL that predicts the time-dependent exciton and free-charge populations. It provides a clear representation of competing mono- and bimolecular recombination processes. A decrease in carrier lifetime with increasing laser intensity was observed that was attributed to exciton-exciton scattering. A bimolecular recombination coef?cient of ～10?7 cm3/s was obtained for exciton recombination. As the concentration of photoexcited carriers increases, stronger exciton-exciton annihilation occurs. The exciton-exciton annihilation rate for CsPbBr3 is 3.63 × 10?7 cm3 s?1 at 10-mW laser power. Notably, the exciton-exciton annihilation rate in bulk material is comparable to that obtained for photoexcited CsPbBr3 nanoscale quantum dots.
关键词： carrier recombination,bimolecular recombination,exciton-exciton annihilation,time-resolved photoluminescence,CsPbBr3
更新于2025-09-12 10:27:22
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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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Silver Nanoparticles Enhanced Luminescence and Stability of CsPbBr <sub/>3</sub> Perovskite Quantum Dots in Borosilicate Glass
摘要： Series of silver nanoparticles (NPs) embedded CsPbBr3 quantum dots (QDs) glass was synthesized via the melt-quench method. Ag NPs and CsPbBr3 QDs coexist in the TEM image of the Ag-doped glass sample. Photoluminescence (PL) spectra show that the 0.1 molar ratio Ag2O doped sample had a PL intensity 2.37 times than the undoped sample. This increase is generated by localized surface plasmon resonance coupling between the Ag NPs and CsPbBr3 QDs. Excessive Ag doping weakens the PL intensity due to spectral self-absorption of the Ag NP surface plasmon resonance (SPR). Self-adsorption of SPR is detrimental to luminescence properties because it increases the amount of photogenerated charge carriers which proceed through non-radiative relaxation pathways. In addition, stability results of Ag NP doped-CsPbBr3 QD glass show that they have excellent stability. This study on Ag NP doped-CsPbBr3 QD glass provides a new idea for the future development of perovskite QD optoelectronic devices.
关键词： Borosilicate glass,CsPbBr3 perovskite quantum dots,Luminescence,Stability,Silver nanoparticles
更新于2025-09-12 10:27:22
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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
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All-solution-processed UV-IR broadband trilayer photodetectors with CsPbBr3 colloidal nanocrystals as carriers-extracting layer
摘要： Colloidal quantum dots (CQDs) are very promising nanomaterials for optoelectronics due to their tunable bandgap and quantum confinement effect. Especially, all-inorganic CsPbX3 (X=Br, Cl and I) perovskite nanocrystals (NCs) have attracted enormous interests owing to their promising and exciting applications in photovoltaic devices. In this paper, all-solution-processed broadband photodetectors ITO/ZnO/CsPbBr3/PbS/Au with high-performance were presented. The role of CsPbBr3 QDs layer as the carriers-extracting layer in the trilayer devices was discussed. As compared with bilayer device ITO/ZnO/PbS/Au, both the dark currents and photocurrents under illumination from UV-IR broadband trilayer photodetector ITO/ZnO(80nm)/PbS(150nm)/CsPbBr3(50nm)/Au are enhanced, but the trilayer photodetector ITO/ZnO(80nm)/CsPbBr3(50nm)/PbS(150nm)/Au showed a maximum specific detectivity (D*) of 1.73×1012 Jones with a responsivity (R) of 5.31 A/W under 6.8 mW/cm2 405 nm illumination. However, another trilayer photodetector ITO/ZnO(80nm)/PbS(150nm)/CsPbBr3(50nm)/Au showed a maximum D* of 8.3×1012 Jones with a R of 35 A/W under 1.6 mW/cm2 980 nm illumination. Further, the underlying mechanism for the enhanced performance of trilayer photodetectors was discussed. Thus, this strategy of all-solution-processed heterojunction configuration paves a facile way for broadband photodetectors with high-performance.
关键词： broadband photodetectors,all-solution-processed heterojunction,Colloidal quantum dots (CQDs),CsPbBr3 perovskite nanocrystals,carrier-extraction layer
更新于2025-09-12 10:27:22
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Advanced modification of perovskite surfaces for defect passivation and efficient charge extraction in air-stable CsPbBr3 perovskite solar cells
摘要： All-inorganic cesium lead bromide (CsPbBr3) halide has attracted growing attentions for carbon-based perovskite solar cells (PSCs) owing to its inherent stable lattice in thermal and/or moisture ambient. The main drawback for carbon-based CsPbBr3 PSCs is the low power conversion efficiency (PCE) caused by serious charge recombination at perovskite surface and/or device interfaces. To address this problem, an interface engineering strategy by modifying a polyvinyl acetate (PVAc) polymer with carbonyl group at the interface of CsPbBr3/carbon is implemented to passivate perovskite surface defect states and also to improve energy level alignment between valence band of CsPbBr3 and work function of carbon, suppressing charge recombination and accelerating charge separation. By introducing graphene oxide (GO) layer for further promoting hole extraction and decreasing energy level difference, the PSC with an architecture of FTO/c-TiO2/m-TiO2/CsPbBr3/PVAc/GO/carbon achieves a champion PCE as high as 9.53%, yielding an improvement by 44.0% compared with 6.62% for the original device. Furthermore, the optimal device free of encapsulation exhibits remarkable long-term stability under high humidity, high temperature and continuous illumination in air. This work provides a new polymer as interface modification material for reducing defect states as well as enhancing energy level alignment and suggests an effective approach for fabricating efficient and stable carbon-based CsPbBr3 PSCs.
关键词： Graphene oxide,CsPbBr3 perovskite solar cells,Interface modification,Charge extraction,Polyvinyl acetate
更新于2025-09-12 10:27:22
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Femtosecond-Laser-Induced Precipitation of CsPbBr3 Perovskite Nanocrystals in Glasses for Solar Spectral Conversion
摘要： Inorganic perovskite quantum dots (QDs) and nanocrystals (NCs) have attracted much attention in recent years because of their high photoluminescence quantum yield (PL QY), narrow full width at half maximum, and wide tunability cross the whole visible range. In this work, space- and size-controlled precipitation of CsPbBr3 perovskite NCs was realized through femtosecond laser direct writing method. Precipitation of CsPbBr3 NCs in glasses was confirmed by the energy dispersive spectroscopy, transmission electron microscope analysis and photoluminescence (PL). Growth of CsPbBr3 perovskite NCs in glass was modulated by fs laser irradiation parameters such as repetition rate, pulse energy, and scanning rate, and PL in the range spanning from blue to green was achieved. With well-designed arrangement of CsPbBr3 NCs and the reduction of self-absorption emission, solar concentrator fabricated by fs laser irradiation can realize the spectral conversion and enhance the quantum efficiency of solar cells.
关键词： Glass,All-inorganic perovskite,Spectral conversion,Solar concentrator,Femtosecond laser,Photoluminescence,CsPbBr3,Nanocrystals
更新于2025-09-12 10:27:22