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Influence of PbS Quantum Dots-Doped TiO2 Nanotubes in TiO2 Film as an Electron Transport Layer for Enhanced Perovskite Solar Cell Performance
摘要： Lead sulfide quantum dots-doped titanium dioxide nanotubes (PbS QDs-doped TNTs) were successfully prepared by the hydrothermal and impregnation methods. A thin layer of titanium dioxide (TiO2) comprising of PbS QDs-doped TNTs was applied as an electron transport layer (ETL) in order to improve the planar perovskite solar cell efficiency. The role of incorporating a high surface area of one-dimensional nanotube structure of TiO2 in the conventional TiO2 layer provided a special unidirectional charge transport and a high charge collection. Moreover, doping PbS QDs onto the surface of TNTs modified the electronic and optical properties of the ETL by downshifting the conduction band of TiO2 from ?4.22 to ?4.58 eV, therefore promoting the driving force of an electron injection to the transparent conductive electrode. By varying the concentration of PbS QDs-doped TNTs dispersed in 2-butanol from 0.1 to 0.9 mg/mL, a concentration of 0.3 mg/mL PbS QDs-doped TNTs was the optimum concentration to be mixed with TiO2 solution for the ETL deposition. The best perovskite solar cell performance with the optimum loading of PbS QDs-doped TNTs provided 14.95% power conversion efficiency, which was increased from 12.82% obtained from the cell with pristine TiO2 film as ETL.
关键词： PbS quantum dots (PbS QDs),perovskite solar cells (PSCs),TiO2 nanotubes (TNTs),Electron transport layer (ETL)
更新于2025-09-11 14:15:04
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Micro-structural, optical and vibrational spectra analysis of Lead sulphide, Cadmium doped PbS and Strontium doped PbS nano-structured thin films synthesized through Successive Ionic Layer Adsorption and Reaction technique for solar cell and infrared detector sensor applications
摘要： Nanostructured skinny or thin films have captivated or fascinated the research network all over the entire world. Successive Ionic Layer Adsorption and Reaction technique is well suited for producing large area deposition and multilayer thin films especially for solar cell like Dipping time, precursor concentration and number of process cycle. In the present investigation lead Sulphide (PbS), cadmium and strontium doped PbS thin films are deposited on a glass substrate by SILAR process at room temperature to study the various morphological, structural and optical properties of them.
关键词： Cadmium doped PbS,SILAR technique,Lead sulphide,Strontium doped PbS thin films,Energy gap
更新于2025-09-11 14:15:04
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PbS Quantum Dots as Additives in Methylammonium Halide Perovskite Solar Cells: the Effect of Quantum Dot Capping
摘要： Colloidal PbS quantum dots (QDs) have been successfully employed as additives in Halide Perovskite Solar Cells (PSCs) acting as nucleation centers in the perovskite crystallization process. For this strategy, the surface functionalization of the QD, controlled via the use of different capping ligands, is likely of key importance. In this work, we examine the influence of the PbS QD capping on the photovoltaic performance of methylammonium lead iodide PSCs. We test PSCs fabricated with PbS QD additives with different capping ligands including methylammonium lead iodide (MAPI), cesium lead iodide (CsPI) and 4-aminobenzoic acid (ABA). Both the presence of PbS QDs and the specific capping used have a significant effect on the properties of the deposited perovskite layer, which affects, in turn, the photovoltaic performance. For all capping ligands used, the inclusion of PbS QDs leads to the formation of perovskite films with larger grain size, improving, in addition, the crystalline preferential orientation and the crystallinity. Yet, differences between capping agents were observed. The use of QDs with ABA capping had higher impact on the morphological properties while the employment of CsPI ligand was more effective on the optical properties of the perovskite films. Taking advantage of the improved properties, PSCs based on the perovskite films with embedded PbS QDs exhibit an enhanced photovoltaic performance, observing the highest increase with ABA capping. Moreover, bulk recombination via trap states is reduced when the ABA ligand is used as capping of the PbS QD additives in the perovskite film. We demonstrate how surface chemistry engineering of PbS QD additives in solution-processed perovskite films opens a new approach towards the design of high quality materials, paving the way to improved optoelectronic properties and more efficient photovoltaic devices.
关键词： nucleation centers,PbS quantum dots,perovskite solar cells,photovoltaic performance,capping ligands
更新于2025-09-11 14:15:04
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Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates
摘要： Lead chalcogenide quantum dots (QDs) are promising acceptors for photovoltaic devices that harness the singlet fission (SF) mechanism. The rate of singlet fission of polyacenes in the presence of QDs is a critical parameter in determining the performance of such devices. The present study demonstrates that the rates of SF in a pentacene derivative, 6,13-dipenylpentacene (DPP), are modulated by forming coaggregates with PbS QDs in aqueous dispersions. PbS QDs generally accelerate SF within DPP aggregates, and the extent of acceleration depends on the size of the QD. The average rate of SF increases from 0.074 ps-1 for DPP-only aggregates to 0.37 ps-1 within DPP-D co-aggregates for QDs with radius 2.2 nm, whereas co-aggregation with the smallest (r = 1.6 nm) and largest (r = 2.7 nm) QDs we tried only slightly change the SF rate. The rate variation is associated with (i) the density of surface ligands, which is influenced by the faceting of the PbS surface, and (ii) the local dielectric constant for the DPP. To accelerate SF, the ligands should be dense enough to provide sufficient affinity for DPP aggregates and effectively perturb the perpendicular alignment of DPP monomers within aggregates to increase the intermolecular coupling that promotes SF, but should not be too dense so as to form a low dielectric environment that disfavors SF. The study suggests that it is critical to consider the influence of the microenvironment of QD surface on photophysical processes when fabricating QD/organic hybrid devices.
关键词： pentacene,photovoltaic devices,PbS,quantum dots,singlet fission
更新于2025-09-11 14:15:04
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Cation‐Exchange Synthesis of Highly Monodisperse PbS Quantum Dots from ZnS Nanorods for Efficient Infrared Solar Cells
摘要： Infrared solar cells that utilize low-bandgap colloidal quantum dots (QDs) are promising devices to enhance the utilization of solar energy by expanding the harvested photons of common photovoltaics into the infrared region. However, the present synthesis of PbS QDs cannot produce highly efficient infrared solar cells. Here, a general synthesis is developed for low-bandgap PbS QDs (0.65–1 eV) via cation exchange from ZnS nanorods (NRs). First, ZnS NRs are converted to superlattices with segregated PbS domains within each rod. Then, sulfur precursors are released via the dissolution of the ZnS NRs during the cation exchange, which promotes size focusing of PbS QDs. PbS QDs synthesized through this new method have the advantages of high monodispersity, ease-of-size control, in situ passivation of chloride, high stability, and a “clean” surface. Infrared solar cells based on these PbS QDs with different bandgaps are fabricated, using conventional ligand exchange and device structure. All of the devices produced in this manner show excellent performance, showcasing the high quality of the PbS QDs. The highest performance of infrared solar cells is achieved using ≈0.95 eV PbS QDs, exhibiting an efficiency of 10.0% under AM 1.5 solar illumination, a perovskite-filtered efficiency of 4.2%, and a silicon-filtered efficiency of 1.1%.
关键词： PbS,quantum dots,nanorods,cation exchange,solar cells
更新于2025-09-11 14:15:04
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Highly enhanced solar conversion efficiency of novel layer-by-layer PbS:Hg and CdS quantum dots-sensitized ZnO thin films prepared by sol–gel spin coating
摘要： Owing to superior optical properties, ZnO thin ?lms have immense potential in solar cell preparation. ZnO thin ?lms were prepared by sol–gel technology. However, this is prolonged technique and it necessitates a complex precursor solution. In the present work, ZnO thin ?lms are prepared by sol–gel spin coating with simple precursor, zinc acetate. A very remarkable feature of the method is that polycrystalline, non-abrasive and translucent ?lms were obtained. Additionally, novel PbS:Hg quantum dots (QDs) and CdS QDs are successfully synthesized. Moreover, both types of QDs are deposited layer-by-layer over pure ZnO and Ag:ZnO thin ?lms. The ?lms are characterized by X-ray diffraction, and crystallinity continuation is observed even after the addition of QDs layer. Presence of synthesized QDs over thin ?lms is also con?rmed. The ?lms were also characterized by scanning electron microscopy (SEM) and UV–Vis spectroscopy. Uniform, dense and porous surface morphology is clearly revealed. Sensitized thin ?lms show a huge decline in band gap and large enhancement in ef?ciency. Superior current density (10.87 mA cm?2) is achieved with PbS:Hg/CdS/Ag:ZnO, which leads to enhancement in overall solar conversion ef?ciency by 6.34 times.
关键词： PbS:Hg quantum dots,sol–gel,Ag:ZnO ?lm,CdS quantum dots
更新于2025-09-10 09:29:36