- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Fusing Nanowires into Thin Films: Fabrication of Graded‐Heterojunction Perovskite Solar Cells with Enhanced Performance
摘要： Perovskite solar cells (PSCs) have recently experienced a rapid rise in power conversion efficiency (PCE), but the prevailing PSCs with conventional mesoscopic or planar device architectures still contain nonideal perovskite/hole-transporting-layer (HTL) interfaces, limiting further enhancement in PCE and device stability. In this work, CsPbBr3 perovskite nanowires are employed for modifying the surface electronic states of bulk perovskite thin films, forming compositionally-graded heterojunction at the perovskite/HTL interface of PSCs. The nanowire morphology is found to be key to achieving lateral homogeneity in the perovskite film surface states resulting in a near-ideal graded heterojunction. The hidden role of such lateral homogeneity on the performance of graded-heterojunction PSCs is revealed for the first time. The resulting PSCs show high PCE up to 21.4%, as well as high operational stability, which is superior to control PSCs fabricated without CsPbBr3-nanocrystals modification and with CsPbBr3-nanocubes modification. This study demonstrates the promise of controlled hybridization of perovskite nanowires and bulk thin films for more efficient and stable PSCs.
关键词： nanocrystals,morphology control,heterojunction,solar cells,halide perovskites
更新于2025-11-20 15:33:11
-
Scandium Molybdate Microstructures with Tunable Phase and Morphology: Microwave Synthesis, Theoretical Calculations, and Photoluminescence Properties
摘要： In this paper, scandium molybdate microstructures have been prepared from solution via a microwave heating method. By controlling the experimental parameters such as molar ratio of reagent and reaction time, scandium molybdates with tunable phase and diverse morphologies including snowflakes, microflowers, microsheets, and branched spindles were obtained. The density of states and surface energies of Sc2Mo3O12 were primarily studied from first-principles calculations. An indirect band gap of 3.56 eV was observed for crystalline Sc2Mo3O12, and the surface energies of various facets were determined to be 0.27–0.91 J/m2. The influence of n(Sc3+):n(Mo7O24 6?) (short for Sc/Mo) molar ratio was systematically investigated and well-characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and UV–vis absorption spectroscopy (UV–vis). Results indicate that the Sc/Mo molar ratio has a great effect on the phase and morphology. Diffuse reflection spectra (DRS) revealed the Egap can be readily tuned from 3.69 to 4.16 eV, which is in accordance with the theoretical result. The photoluminescence (PL) properties of Eu3+-doped Sc2Mo3O12 were discussed. This facile synthesis strategy could be extended to the synthesis of other molybdates.
关键词： photoluminescence,morphology control,microwave synthesis,scandium molybdate,density functional theory
更新于2025-09-23 15:23:52
-
Puffing quaternary FexCoyNi1-x-yP nanoarray via kinetically controlled alkaline etching for robust overall water splitting; ?￠±???è???3??????oè?¨???FexCoyNi1a??xa??yP??????é?μ?????????é?? ???è￡?è§￡?°′??§è??;
摘要： Designing and constructing bifunctional electrocatalysts with high efficiency, high stability and low cost for overall water splitting to produce clean hydrogen fuel is attractive but highly challenging. Here we constructed puffed quaternary FexCoyNi1?x?yP nanoarrays as bifunctional electrodes for robust overall water splitting. The iron was used as the modulator to manipulate the electron density of NiCoP nanoarray, which could increase the positive charges of metal (Ni and Co) and P sites. The resultant electronic structure of FexCoyNi1?x?yP was supposed to balance the adsorption and desorption of H and accelerate the oxygen evolution reaction (OER) kinetics. Moreover, the morphological structure of FexCoyNi1?x?yP was modulated through the kinetically controlled alkaline etching by using the amphoteric features of initial FeCoNi hydroxide nanowires. The resultant puffed structure has rich porosity, cavity and defects, which benefit the exposure of more active sites and the transport of mass/charge. As a result, the cell integrated with the puffed quaternary FexCoyNi1?x?yP nanoarrays as both the cathode and anode only requires the overpotentials of 25 and 230 mV for hydrogen evolution reaction (HER) and OER at the current density of 10 mA cm?2 in alkaline media and a cell voltage of 1.48 V to drive the overall water splitting. Moreover, the puffed FexCoyNi1?x?yP demonstrates remarkable durability for continuous electrolysis even at a large current density of 240 mA cm?2.
关键词： water splitting,puffed nanoarray,electrocatalysis,morphology control,alkaline etching
更新于2025-09-23 15:21:01
-
Over 14% Efficiency Nonfullerene All-Small-Molecule Organic Solar Cells Enabled by Improving the Ordering of Molecular Donor via Side-Chains Engineering
摘要： Improving the short current density (Jsc) is a big challenge for gaining highly efficient nonfullerene all-small-molecule organic solar cells (NFASM-OSCs). Herein, a novel small molecular donor, BT-2F which is derived from previously reported BTEC-2F, was designed and synthesized. The shortened alkyl-chains with higher regularity endow BT-2F with more ordered packing arrangement and more compact lamellar stacking as evidenced by the characterization of differential scanning calorimetry and grazing incidence X-ray diffraction. By blending BT-2F with Y6 or N3, BT-2F based devices showed impressive power conversion efficiencies (PCEs) of 13.80% and 14.09% respectively, much higher than the reported PCE of 13.34% for BTEC-2F:Y6. Besides, the efficiency of 14.09% is also among the highest PCE value reported so far for NFASM-OSCs. The distinctly improved Jsc devoted major efforts to enhancing the PCE values, meanwhile both BT-2F:Y6 and BT-2F:N3 still keep the high fill factors over 70%, which are ascribed to the good balance between high crystallinity and proper phase separation.
关键词： Morphology control,Crystallinity,Highly efficient nonfullerene organic solar cells,Molecular packing arrangement,Molecule design
更新于2025-09-23 15:19:57
-
High-Performance Ternary Organic Solar Cells with Controllable Morphology via Sequential Layer-by-Layer Deposition
摘要： Ternary blending of light harvesting materials has been proven to be a potential strategy to improve the efficiency of solution processed organic solar cells (OSCs). However, the optimization of ternary system is usually more complicated than the binary one as the morphology of conventional ternary blend films is very difficult to control, thus undermining the potential of ternary OSCs. Herein, we report a general strategy for better control of the morphology of ternary blend films composed of a polymer donor and two non-fullerene small molecule acceptors for high-performance OSCs using sequential layer-by-layer (LbL) deposition method. The resulted LbL films form bicontinuous interpenetrating network structure with high crystallinity of both the donor and acceptor materials, showing efficient charge generation, transport and collection properties. In addition, the power conversion efficiencies (PCEs) of the ternary LbL OSCs are less sensitive to the blending ratio of the third component acceptor, providing more room to optimize the device performance. As a result, optimal PCEs of over 11%, 13 % and 16 % were achieved for the LbL OSCs composed of PffBT4T-2OD/IEICO-4F:FBR, PBDB-T-SF/IT-4F:FBR and PM6/Y6:FBR, respectively. Our work provides useful and general guidelines for the development of more efficient ternary OSCs with better controlled morphology.
关键词： sequential layer-by-layer deposition,non-fullerene acceptor,ternary organic solar cell,high performance,morphology control
更新于2025-09-23 15:19:57
-
Innovative visualization of crystal morphology effects on semiconductor photocatalysts. Tuning the Hückel polarity of the shape-tailoring agents: the case of Bi2WO6
摘要： The shape tailoring synthesis of different materials is a hot topic nowadays. The essence of morphology controlling processes is to tune the geometry of the crystal in such a way that a desired property of the crystal to be preponderantly enhanced. However, the main issue of such synthesis approaches is to get simple morphological correlations with the applied shape-tailoring agents. This specific situation is also valid for shape controlled photocatalytic materials. That is why in the present work Bi2WO6 microcrystals were obtained using two shape tailoring agents: Triton-X and amino acids/(tio)carbamide structures. The first one was applied as a binary variable (presence or absence), while in the case of the second one the Hückel polarity of the chalcogen-carbon double bond (C=O or S) was considered as the changing parameter. The as-prepared materials were characterized by XRD, DRS, SEM and IR spectroscopy and their activity was verified under visible light illumination using Rhodamine B as the model pollutant to enhance the general validity of the results. It was found that an empiric geometric function, defined as the “rose similarity decay constant”-RSDC, showed that a perfect rose shape (low RSDC) or geometries with similarly low RSDC exhibited high photocatalytic activity. Moreover, the introduced empiric value was correlated with the Hückel polarity of the samples, showing for the first time a direct association between a structural parameter of the shape tailoring agent, obtained crystal geometry and photoactivity.
关键词： rose similarity decay constant,morphology control,Hückel polarity,photocatalysis,bismuth tungstate,shape-tailoring
更新于2025-09-19 17:15:36
-
Green Synthesis of Bismuth Sulfide Nanostructures with Tunable Morphologies and Robust Photoelectrochemical Performance
摘要： Manipulating the morphology of chalcogenide semiconductor crystals to tailor their shape- and size-dependent properties is much desired but remains a grand challenge. Herein, we for the first time develop a green, facile and surfactant-free hydrothermal approach for the synthesis of bismuth sulfide (Bi2S3) with highly tunable morphologies in H2WO4 aqueous solution. The H2WO4 is prone to balance the concentration of Bi3+ to S2- in aqueous solution, thus modulating the nucleation and epitaxial growth of Bi2S3. Specifically, in the presence of lower H2WO4 concentration, low number of Bi2S3 nuclei facilitates the preferred growth of nanorod structures along [001] direction, while the Bi-deficient, S-rich conditions in higher H2WO4 concentration give rise to Bi2S3 nanotubes, presumably due to the stronger interlayer interaction and preferred growth in [hk0] direction. The resulting Bi2S3 nanostructures exhibit broad absorption overlapping UV-Visible-NIR regions and red-shifted absorption edges owing to the increased S/Bi molar ratio in Bi2S3 lattices. The Bi2S3 nanorods with higher aspect ratio demonstrate an enhanced photocurrent response by virtue of the improved charge carrier mobility along [001] direction. Different from previous synthetic methodologies, this work details a facile, effective, and environmentally-benign protocol for the synthesis of Bi2S3 nanomaterials in the aqueous medium without any organic reagents. Noteworthy, the excellent and tailorable photoelectrochemical (PEC) performance endows these Bi2S3 nanostructures with vast potential in solar cell and photodetector applications.
关键词： Photoelectrochemical performance,Morphology control,Nanostructures,Green synthesis,Bismuth sulfide
更新于2025-09-19 17:15:36
-
Efficient and stable planar all-inorganic perovskite solar cells based on high-quality CsPbBr3 films with controllable morphology
摘要： All-inorganic cesium lead bromide (CsPbBr3) perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability. However, the fabrication of high-quality CsPbBr3 films still remains a big challenge by solution-process because of the low solubility of the cesium precursor in common solvents. Herein, we report a facile solution-processed approach to prepare high-quality CsPbBr3 perovskite films via a two-step spin-coating method, in which the CsBr methanol/H2O mixed solvent solution is spin-coated onto the lead bromide films, followed by an isopropanol-assisted post-treatment to regulate the crystallization process and to control the film morphology. In this fashion, dense and uniform CsPbBr3 films are obtained consisting of large crystalline domains with sizes up to microns and low defect density. The effectiveness of the resulting CsPbBr3 films is further examined in perovskite solar cells (PSCs) with a simplified planar architecture of fluorine–doped tin oxide/compact TiO2/CsPbBr3/carbon, which deliver a maximum power conversion efficiency of 8.11% together with excellent thermal and humidity stability. The present work offers a simple and effective strategy in fabrication of high-quality CsPbBr3 films for efficient and stable PSCs as well as other optoelectronic devices.
关键词： CsPbBr3,Morphology control,Stability,All-inorganic perovskite solar cells,Solution-processed
更新于2025-09-12 10:27:22
-
Perylene Diimide based Organic Photovoltaics with Slot-Die Coated Active Layers from Halogen-Free Solvents in Air at Room Temperature
摘要： Herein, we investigate the role of processing solvent additives on the formation of polymer-perylene diimide bulk-heterojunction active layers for organic photovoltaics using both spin-coating and slot-die coating methods. We compare the effect of 1,8-diiodooctane (DIO) and diphenyl ether (DPE) as solvent additives on the aggregation behavior of the non-fullerene acceptor tPDI2N-EH in neat films and blended films with the benzodithiophene-quinoxaline (BDT-QX, QX-3) donor polymer, processed from toluene in air. DIO-processing crystallizes the tPDI2N-EH acceptor and leads to decreased solar cell performance. DPE-processing has a more subtle effect on the bulk-heterojunction morphology and leads to improved solar cell performance. Comparing spin vs. slot-die coating methods, the effect of DPE is prominent for slot-die coated active layers. While similar device power conversion efficiencies are achieved with active layers coated with both methods (ca. 7.3% vs. 6.5%), the use of DPE improves film quality when the slot-die coating method is employed.
关键词： Organic photovoltaics,Halogen-free processing,Perylene diimide,Slot-die coating,Solvent additive,Diphenyl ether,Quinoxaline,Morphology control
更新于2025-09-12 10:27:22
-
Fine-Tuning Semiconducting Polymer Self-Aggregation and Crystallinity Enables Optimal Morphology and High-Performance Printed All-Polymer Solar Cells
摘要： Polymer aggregation and crystallization behavior play a crucial role in the performance of all-polymer solar cells (all-PSCs). Gaining control over polymer self-assembly via molecular design to influence bulk-heterojunction active-layer morphology, however, remains challenging. Herein, we show a simple yet effective way to modulate the self-aggregation of the commonly used naphthalene diimide (NDI)-based acceptor polymer (N2200), by systematically replacing a certain amount of alkyl side-chains with compact bulky side-chains (CBS). Specifically, we have synthesized a series of random co-polymer (PNDI-CBSx) with different molar fractions (x = 0–1) of the CBS units and have found that both solution-phase aggregation and solid-state crystallinity of these acceptor polymers are progressively suppressed with increasing x as evidenced by UV-Vis absorption, photoluminescence (PL) spectroscopies, thermal analysis and grazing incidence X-ray scattering (GIWAXS) techniques. Importantly, compared to the highly self-aggregating N2200, photovoltaic results show that blending of more amorphous acceptor polymers with donor polymer (PBDB-T) can enable all-PSCs with significantly increased PCE (up to 8.5%). The higher short-circuit current density (Jsc) results from the smaller polymer phase-separation domain sizes as evidenced by PL quenching and resonant soft X-ray scattering (R-SoXS) analyses. Additionally, we show that the lower crystallinity of the active layer is less sensitive to the film deposition methods. Thus, the transition from spin-coating to solution coating can be easily achieved with no performance losses. On the other hand, decreasing aggregation and crystallinity of the acceptor polymer too much, reduces the photovoltaic performance as the donor phase-separation domain sizes increases. The highly amorphous acceptor polymers appear to induce formation of larger donor polymer crystallites. These results highlight the importance of a balanced aggregation strength between the donor and acceptor polymers to achieve high-performance all-PSCs with optimal active layer film-morphology.
关键词： morphology control,crystallinity,polymer aggregation,naphthalene diimide,all-polymer solar cells
更新于2025-09-11 14:15:04