- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The Balance between Energy Transfer and Exciton Separation in Ternary Organic Solar Cells with Two Conjugated Polymer Donor
摘要： Ternary strategy as a straightforward way for organic solar cells (OSCs) to improve the device performance attracts many interests in the field. The ternary strategy usually focuses on processing the third light-absorbing material owning a complementary absorption to the binary system. However, studying the third component with similar absorption spectra to the binary counterpart is equally essential to understand the in-depth mechanism of the performance improvement from the third component. In this work, we filled up this blank and derived a type of ternary device consisting of two conjugated polymer donor materials of PTB7-Th and PffBT4T-2OD and non-fullerene acceptor material of IEICO-4F. The average PCE value of the optimized ternary device reached 12.1%, which is around 16% higher than its PTB7-Th:IEICO-4F binary counterpart. Even the third component of PffBT4T-2OD containing a similar absorption spectrum with PTB7-Th, it was found that the Jsc increase contributes to the primary performance enhancement. Further investigations indicate that the Jsc increase in the optimized ternary device mainly came from the improved light absorption ability, current extraction process, charge transport process, and suppressed non-radiative recombination. Moreover, there is a balance found between the exciton separation process and the energy transfer process when optimizing ternary blend ratios. The optimized ternary device is suspected to reach this balance point and thus exhibits the enhancement in device performance. Morphology investigation reveals that the addition of PffBT4T-2OD can tune the morphology and increase the crystallinity in the active layer. The optimized ternary blend shows a well-mixed donor and acceptor morphology with small domain size and slightly increased crystallization, which further explained its best device performance.
关键词： non-fullerene,energy transfer,exciton separation,organic solar cells,ternary,crystallization,conjugated polymer
更新于2025-09-23 15:21:01
-
Different Silver Nanoparticles in One Crystal: Ag210(iPrPhS)71(Ph3P)5Cl and Ag211(iPrPhS)71(Ph3P)6Cl
摘要： Two pure silver nanoparticles (Ag210(iPrPhS)71(Ph3P)5Cl and Ag211(iPrPhS)71(Ph3P)6Cl labeled as SD/Ag210 and SD/Ag211 (SD = SunDi), were found to co-crystallize in forming compound 1. Single-crystal X-ray diffraction (SCXRD) revealed that they differ by only one Ag(PPh3). Their four-shell nanoparticles consist of three pure Ag metal shells (Ag19@Ag52@Ag45) shielded by a silver-organic Ag89(iPrPhS)71Cl[Ag(Ph3P)]n. outermost shell. The number (n) of Ag(Ph3P) is five for SD/Ag210 and six for SD/Ag211. The pseudo-fivefold symmetric Ag nanoparticles exhibit surface plasmon absorption similar to a true metallic state but at the nanoscale. The attributes of this work are i) it exemplifies the important effects of phosphine in stabilizing large silver nanoparticles; ii) it offers a platform to investigate the origin of differences in nanoscale metal materials, even differing by only one metal atom; and iii) it sheds light on the regioselective binding of auxiliary Ph3P on the surface of silver nanoparticles.
关键词： co-crystallization,core-shell,silver nanoparticles,alkyne,surface plasmon
更新于2025-09-23 15:21:01
-
Layered Nonstoichiometric V <sub/>7</sub> O <sub/>16</sub> Thin Films with Controlled Oxygen-Deficient Multivalent States and Crystalline Phases
摘要： Layered nonstoichiometric vanadium oxides have aroused strong interest in energy conversion, storage, chemical catalysis, sensors and optoelectronic devices. It is still a critical challenge to control unique atomic-layer constructions and oxygen-dependent multivalent states in layered metal oxides. Here, we demonstrated the layered nonstoichiometric V7O16 thin films with controlled multivalent states and crystalline phases obtained by the combination of atomic layer deposition (ALD) and oxygen-dependent crystallization. The nonstoichiometric composition and crystalline microstructures are dominated by the oxidation states of vanadium and the thicknesses of the pristine films during the formation of layered V7O16 thin films. Variable-temperature optical and electrical behaviors suggest that no abrupt electronic and structural transitions are observed in the layered V7O16 thin films at a temperature ranging from 78 to 475 K. We expect that the oxygen-dependent multivalent states and crystalline phases in layered V7O16 will provide more opportunities to fabricate layered oxides and electrochemical devices based on nonstoichiometric vanadium oxides.
关键词： atomic layer deposition,vanadium oxide,layered oxide,V7O16,oxygen-dependent crystallization
更新于2025-09-23 15:19:57
-
Liquid State and Zombie Dye Sensitized Solar Cells with Copper Bipyridine Complexes Functionalized with Alkoxy Groups
摘要： Copper redox mediators can be employed in dye sensitized solar cells (DSCs) both as liquid electrolyte or as solid state hole transport materials (HTMs). The solid state devices, employing copper complex HTMs can be simply obtained by solvent evaporation in liquid state devices. During this evolution, the copper complex molecules present in the electrolyte solvent slowly aggregate in the pores of the TiO2 film and they also close the gap between the TiO2 film and counter electrode. However, the crystallization of the HTM infiltrated in the mesoscopic TiO2 pores can lead to low photovoltaic performance. In order to prevent this problem, we designed two copper redox mediators [Cu(beto)2]1+ (beto=4,4’-diethoxy-6.6’-dimethyl-2,2’-bipyridine) and [Cu(beto2Ox)2]1+ (beto2Ox=4,4’-bis(2-methoxyethoxy)-6,6’-dimethyl-2,2’-bipyridine) with extended side chains. Firstly, we studied these complexes in liquid state devices in reference to the [Cu(tmby)2]2+/1+ complex (tmby = 4,4?,6,6?- tetramethyl-2,2?-bipyridine). The solar-to-electrical power conversion efficiencies for liquid state devices, were over 10% for all of the complexes by using the organic Y123 dye under 1000 Wm-2 AM1.5G illumination. However, solid state devices showed significantly diminished charge transport properties and short circuit current density values even though the crystallization is reduced.
关键词： Hole transport materials,Dye sensitized solar cells,Crystallization,Photovoltaic performance,Copper redox mediators
更新于2025-09-23 15:19:57
-
Employing a Narrow-bandgap Mediator in Ternary Solar Cells for Enhanced Photovoltaic Performance
摘要： Ternary organic solar cells (OSCs) provide a convenient and effective means to further improve the power conversion efficiency (PCE) of binary ones via composition control. However, the role of the third component remains to be explored in specific binary systems. Herein, we report ternary blend solar cells by adding the narrow-bandgap donor PCE10 as the mediator into the PBDB-T:IDTT-T binary blend system. The extended absorption, efficient fluorescence resonance energy transfer, enhanced charge dissociation and induced tighter molecular packing of the ternary blend films enhance the photovoltaic properties of devices and deliver a champion PCE of 10.73% with an impressively high open-circuit voltage (VOC) of 1.03 V. Good miscibility and similar molecular packing behavior of the components guarantee the desired morphology in the ternary blend films, leading to solar cell devices with over 10% PCEs at a range of compositions. Our results suggest ternary systems with properly aligned energy levels and overlapping absorption amongst the components hold great promises to further enhance performance of corresponding binary ones.
关键词： ternary solar cell,energy transfer,induced crystallization property,non-fullerene acceptors,molecular mediator
更新于2025-09-23 15:19:57
-
Thermally Stable Perovskite Solar Cells with Efficiency over 21% via Bifunctional Additive
摘要： The rapid improvements in performance of organic-inorganic perovskite solar cells has been astonishing but its commercialized production requires further achievements on device stability and efficiency. Herein, we introduce a bifunctional additive, biuret, with multiple Lewis base groups to regulate the crystallization process of perovskite crystals and passivate the defects at grain boundaries. Compared with the control, methylammonium lead iodide (MAPbI3), films processed with biuret exhibit increased grain size, reduced trap states density, and more uniform local photoluminescence. The addition of biuret leads to suppressed trap-assisted nonradiative recombination and an efficiency improvement from 18.26% to 21.16%, which is among the highest efficiency for MAPbI3 solar cells with the mesoscopic structure. Meanwhile, as biuret interacts with uncoordinated Pb2+ and iodide from the iodoplumbate complex on two adjacent perovskite grains, the thermal durability of MAPbI3 film is enhanced due to the crosslink through chemical bonding. Under 85°C annealing in nitrogen, the biuret-modified device preserves 94% of its initial efficiency after 12 days while the control cells lose more than half the efficiency.
关键词： crystallization,defect passivation,bifunctional additive,perovskite solar cell,stability
更新于2025-09-23 15:19:57
-
Vacuum-Controlled Growth of CsPbI <sub/>2</sub> Br for Highly Efficient and Stable All-Inorganic Perovskite Solar Cells
摘要： A high temperature annealing process (> 250°C) is always needed to obtain high-quality CsPbI2Br perovskite films, which makes it a challenge in the manufacture and application of flexible photovoltaic devices. In this work, a vacuum-controlled growth (VCG) that can effectively control the crystallization of perovskite and obtain high-quality films with larger grain size and low defect density at lower temperature is demonstrated. Besides a facile introduction of polyethyleneimine (PEIE) interlayer improves the charge extraction and suppresses carrier recombination. Therefore, the power conversion efficiency (PCE) of all-inorganic CsPbI2Br perovskite solar cell (PSC) reaches 12.32%. The unencapsulated PSCs with VCG treatment and PEIE modification show outstanding stabilities with retaining over 95% of initial PCE after being stored in N2 glove-box for over 1000h. This low temperature crystallization method and cheap transport material introduction drive the development for future commercialization of all inorganic perovskite solar cells.
关键词： vacuum controlled growth,interface modification,All inorganic perovskite solar cells,crystallization control,low temperature,film fabrication
更新于2025-09-23 15:19:57
-
Development of technology for robotic laser welding of thin-walled products from heat-resistant alloys
摘要： The results of testing the modes of robotic laser welding of spatial welded joints of thin-walled products from heat-resistant steels are considered. Comparative studies of the influence of the parameters of various methods of industrial welding on the metallography of the weld and the technological strength of the welded joint are presented. The resistance of welded joints against the formation of crystallization (hot) cracks is evaluated.
关键词： heat-resistant alloys,robotic laser welding,technological strength,metallography,crystallization cracks,thin-walled products
更新于2025-09-23 15:19:57
-
Uneven Crystallization of a-Si and a-Si: Ag Thin Films Irradiated by Femtosecond Laser
摘要： The crystallization of both a-Si and a-Si:Ag thin films by femtosecond laser irradiation has been studied recently. It is found that there is an uneven crystallization in both amorphous thin films by means of optical microscopy and laser Raman spectroscopy respectively. The crystallization in each pulse spot area is gradually weakened from the center to the edge along with the energy dispersion of laser irradiation. The laser induced crystallization in a-Si films begins early and develops more extensively compared to that in a-Si:Ag thin films, and Ag nanoparticles inhibits somehow the crystallization of a-Si in a-Si:Ag films.
关键词： a-Si,a-Si:Ag,femtosecond laser,crystallization,Raman spectroscopy
更新于2025-09-23 15:19:57
-
Preparation of Fe-Co-B-Si-Nb bulk metallic glasses by laser powder bed fusion: Microstructure and properties
摘要： In this work, laser powder bed fusion (LPBF) was employed for the preparation of {(Fe0.6Co0.4)0.75B0.2Si0.05}96Nb4 bulk metallic glasses (BMGs). Microstructural evolution, thermal stability and mechanical properties of LPBF-processed samples using different laser power and scanning speed were systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microscopy analysis (EPMA), electron backscatter diffraction (EBSD), differential scanning calorimetry (DSC) and nanoindentation. The results show that low area energy input facilitates the formation of Fe-Co-B-Si-Nb BMGs with a large amorphous fraction. LPBF-processed sample with an area energy density of 1.25 J/mm2 (at a laser power of 60 W and a scanning speed of 600 mm/s) exhibits a nearly fully glassy microstructure with an amorphous fraction of approximately 99%, meanwhile identical characteristic properties of LPBF-processed samples are correlated with the processing parameters during LPBF. This work demonstrates that LPBF is a promising method to prepare fully amorphous Fe-Co-B-Si-Nb BMGs. The results provide key insights for the fabrication of BMGs and BMGs composites with the desired microstructure possessing almost and properties by additive manufacturing.
关键词： Bulk metallic glasses,Laser powder bed fusion,Amorphous fraction,Crystallization,Microstructure,Nanoindentation
更新于2025-09-23 15:19:57