- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Coral-Like Perovskite Nanostructures for Enhanced Light-Harvesting and Accelerated Charge Extraction in Perovskite Solar Cells
摘要： A novel coral-like perovskite nanostructured layer was grown on a compact perovskite foundation layer by the facile surface modification with dimethylformamide/isopropanol (DMF/IPA) as co-solvent. Surface morphological characterizations with SEM and XRD analyses revealed a growing mechanism of the new morphology, which was composed of the perovskite decomposition and recrystallization, excessive-PbI2 extraction, and sequential formation of coral-like nanostructured perovskite layer. The coral-like perovskite nanostructures resulted in significant light scattering, enhancing the light harvesting efficiency, and thus augmenting the photocurrent density. Moreover, the geometric configuration of the perovksite solar cells was changed from planar to bulk heterojunction, which results in the acceleration of charge separation and extraction due to the high surface area at the interface between the obtained perovskite and hole-transport layers. The optimal perovskite solar cell exhibited an impressive power conversion efficiency (PCE) of 19.47%, as compared to that of the pristine cell (17.19%).
关键词： solar cells,Bulk heterojunction,light-harvesting,coral-like nanostructures,surface modification,perovskite
更新于2025-11-21 11:01:37
-
Steady Enhancement in Photovoltaic Properties of Fluorine Functionalized Quinoxaline-Based Narrow Bandgap Polymer
摘要： To investigate the influence of fluoride phenyl side-chains onto a quinoxaline (Qx) unit on the photovoltaic performance of the narrow bandgap (NBG) photovoltaic polymers, herein, two novel NBG copolymers, PBDTT-DTQx and PBDTT-DTmFQx, were synthesized and characterized. 2-ethylhexylthiothiophene-substituted benzodithiophene (BDTT), 2,3-diphenylquinoxaline (DQx) [or 2,3-bis(3-fluorophenyl)quinoxaline (DmFQx)] and 2-ethylhexylthiophene (T) were used as the electron donor (D) unit, electron-withdrawing acceptor (A) unit and π-bridge, respectively. Compared to non-fluorine substituted PBDTT-DTQx, fluoride PBDTT-DTmFQx exhibited a wide UV-Vis absorption spectrum and high hole mobility. An enhanced short-circuit current (Jsc) and fill factor (FF) simultaneously gave rise to favorable efficiencies in the polymer/PC71BM-based polymer solar cells (PSCs). Under the illumination of AM 1.5G (100 mW cm?2), a maximum power conversion efficiency (PCE) of 6.40% was achieved with an open-circuit voltage (Voc) of 0.87 V, a Jsc of 12.0 mA cm?2 and a FF of 61.45% in PBDTT-DTmFQx/PC71BM-based PSCs, while PBDTT-DTQx-based devices also exhibited a PCE of 5.43%. The excellent results obtained demonstrate that PBDTT-DTmFQx by fluorine atom engineering could be a promising candidate for organic photovoltaics.
关键词： quinoxaline,synthesis,polymer solar cells,bulk heterojunction,narrow bandgap conjugated polymer
更新于2025-11-19 16:56:42
-
Effects of fluorination and thermal annealing on charge recombination processes in polymer bulk-heterojunction solar cells
摘要： We investigate the effect of fluorination on the photovoltaic properties of an alternating conjugated polymer composed of 4,8-di-2-thienylbenzo[1,2-b:4,5-b0]dithiophene and 4,7-bis([2,20-bithiophen]-5-yl)-benzo-2-1-3-thiadiazole (4TBT) units in bulk-heterojunction solar cells. The unsubstituted and fluorinated polymers afford very similar open-circuit voltages and fill factor values, but the fluorinated polymer performed better due to enhanced aggregation which provides a higher photocurrent. The photovoltaic performance of both materials improved upon thermal annealing at 150–200 °C as a result of a significantly increased fill factor and open-circuit voltage, counteracted by a slight loss in photocurrent. Detailed studies of the morphology, light intensity dependence, external quantum efficiency and electroluminescence allowed the exploration of the effects of fluorination and thermal annealing on the charge recombination and the nature of the donor–acceptor interfacial charge transfer states in these films.
关键词： polymer bulk-heterojunction solar cells,thermal annealing,charge recombination,fluorination,photovoltaic properties
更新于2025-10-22 19:40:53
-
Photocathodic hydrogen evolution from catalysed nanoparticle films prepared from stable aqueous dispersions of P3HT and PCBM
摘要： Photo-assisted hydrogen evolution is achieved on photocathodes comprising of nanoparticles of poly(3-hexylthiophene) (npP3HT) and nanoparticles of phenyl-C61-butyric acid methyl ester (npPCBM) onto which ultra-low loadings of Pt nanoparticles are deposited. The nanoparticles, npP3HT and npPCBM, are prepared individually via miniemulsion using surfactants of opposite head group polarity. Aqueous dispersions of npP3HT:npPCBM, devoid of organic solvent, are cast conformally onto ITO-coated glass to yield water-insoluble bulk-heterojunction films. Pt is deposited photoelectrochemically onto ITO/npP3HT:npPCBM photocathodes and found to nucleate preferentially on PCBM nanoparticles. ITO/npP3HT:npPCBM/Pt photocathodes produce 65 μA/cm2 photocurrent under 100 mW/cm2 of visible light at 0.0 VSHE and liberate H2 gas. The photocurrents observed for electrodes prepared using npP3HT:npPCBM are twice as large, and the onset potential is ～0.4 V more positive than analogous photocathodes cast from nanoparticles each comprising an intimate blend of P3HT and PCBM. These are encouraging results for large scale synthesis of organic photoelectrochemical devices, given the simplicity of the photoelectrode, i.e., prepared from aqueous solutions and devoid of vacuum-deposited films such as charge transport layers and protective films.
关键词： Polymer nanoparticle,Photoelectrochemistry,P3HT: PCBM bulk-heterojunction,Solar hydrogen generation,Organic semiconductor,Mini-Emulsion
更新于2025-09-23 15:23:52
-
Significant Enhancement of Hole Transport Ability in Conjugated Polymer/Fullerene Bulk Heterojunction Microspheres
摘要： Bulk heterojunction (BHJ) strategy requires morphology of wide area donor-acceptor interfaces with high charge carrier mobilities through the bicontinuous charge transporting layers. Here, we report formation of well-defined bulk heterojunction (BHJ) microspheres from regiorandom poly(hexylthiophene) (rra-PHT)/phenyl-C61-butyric acid methyl ester (PCBM) mixture by a vapor diffusion method. By electrochemical oxidation, the BHJ microsphere exhibits enhanced generation of PHT cation species due to increased hole-transport property in comparison with a solution-cast film derived from rra-PHT/PCBM mixture without microsphere morphology. Photoconductivity and electrochemical stability of the microsphere are comparable or even higher than a cast film of irregular aggregates of regioregular P3HT.
关键词： polythiophene,bulk heterojunction,microspheres,electrochemistry,fullerene
更新于2025-09-23 15:22:29
-
An inverted ZnO/P3HT:PbS bulk-heterojunction hybrid solar cell with a CdSe quantum dot interface buffer layer
摘要： An inverted bulk-heterojunction (BHJ) hybrid solar cell having the structure ITO/ZnO/P3HT:PbS/Au was prepared under ambient conditions and the device performance was further enhanced by inserting an interface buffer layer of CdSe quantum dots (QDs) between the ZnO and the P3HT:PbS BHJ active layer. The device performance was optimized by controlling the size of the CdSe QDs and the buffer layer thickness. The buffer layer, with an optimum thickness and QD size, has been found to promote charge leading to an increased open-circuit voltage (VOC), extraction and reduces interface recombinations, short circuit current density (JSC), fill factor (FF) and power conversion efficiency (PCE). About 40% increase in PCE from 1.7% to 2.4% was achieved by the introduction of the CdSe QD buffer layer, whose major contribution comes from a 20% increase of VOC.
关键词： CdSe quantum dots,inverted bulk-heterojunction,interface buffer layer,hybrid solar cell,power conversion efficiency
更新于2025-09-23 15:21:01
-
High-Efficiency Perovskite Quantum Dot Solar Cells Benefiting from a Conjugated Polymer-Quantum Dot Bulk Heterojunction Connecting Layer
摘要： In this work, we reported an efficient and universal method to fabricate perovskite quantum dot (PQD) solar cells with enhanced efficiency. Through dissolving optimal amount conjugated polymers in PQD matrix solution to fabricate a polymer-QD bulk heterojunction hybrid layer located at PQD/hole transporting layer (HTL) interfaces, the resultant solar cell devices exhibit significantly enhanced short-circuit current density and efficiency. In-depth characterizations indicate that adding optimal conjugated polymer into the PQD film can effectively reduce pin-holes, resulting in more efficient interfacial charge transfer and decreased carrier recombination loss. More importantly, it shows that the highest occupied molecular orbital (HOMO) energy level of the conjugated polymer is crucial for achieving improved carrier transport at the PQD/HTL interfaces. Through rational selection of conjugated polymers, we achieved the best power conversion efficiency of ~14% and 13.2% for CsPbI3 and FAPbI3 PQD based solar cells respectively, situating the forefront of all reported PQD solar cells. These findings would provide insights into well controlling the organic-inorganic interfaces to improve photovoltaic devices.
关键词： interfacial modification,solar cells,perovskite quantum dot,bulk heterojunction,conjugated polymer
更新于2025-09-23 15:21:01
-
Carbazole Green and Blue-BODIPY Dyads and Triads as Donors for Bulk Heterojunction Organic Solar Cells
摘要： Two BODIPY derivatives with one (B2) and two (B3) carbazole moieties were designed, synthesized and applied as electron-donor materials in organic photovoltaic cells (OPV). The optical and electrochemical properties were systematically investigated. These BODIPY dyes exhibit excellent solubility in organic solvents and present high molar extinction coefficients (1.37–1.48 x 105 M-1 cm-1) in solutions with absorption maxima at 586 nm for mono-styryl group and at 672 nm for di-styryl groups. The introduction of the styryl moieties result in a large bathochromic shift and a significant decrease in the HOMO-LUMO energy-gaps. The BODIPY dyes show relatively low HOMO energies ranging from -4.99 to -5.16 eV as determined from cyclic voltammetry measurements. Cyclic voltammetry measurements and theoretical calculations demonstrate that the frontier molecular orbital levels of these compounds match with PC71BM as the acceptors, supporting their application as donor materials in solution-processed small molecule bulk heterojunction (BHJ) organic solar cells. After the optimization of the active layer, B2:PC71BM and B3:PC71BM based organic solar cells showed the overall power conversion efficiency of 6.41% and 7.47%, respectively. The higher PCE of B3 based OSC is ascribed to the more balanced charge transport and exciton dissociation, better crystalline and molecular packing.
关键词： bulk heterojunction,Green and blue-BODIPY,electrochemistry,power conversion efficiency
更新于2025-09-23 15:21:01
-
Influence of P3HT preaggregation process on performance of the P3HT:C60-PCBM solar cells
摘要： The bulk heterojunction based created by poly(3-hexyltiophene-2,5-diyl) (P3HT phenyl-C61-butyric acid methyl ester (C60-PCBM) it is well-known system used in organic solar cells. As the performance of such solar cells are very sensitive to the processing conditions of the active layers, we have focused attention to preaggregation process of P3HT in the aged solutions, which can be one of the reasons behind the different values of the reported efficiencies for this solar cell system. In this work, we present a systematic study of the influence of aging time of solutions mixture of P3HT:C60-PCBM in different solvents on the performance of the photovoltaic cells. The highest efficiency values were obtained from devices based on active layer dissolved in 1,2-dichlorobenzene. These values were stable even after 120 h of aging solutions, which means that the solution ageing process does not affect the final device properties. While, in chloroform and toluene solvents, efficiency of solar cells decreases within aging process. Our processing approach allows to better understanding the relationship between morphology of P3HT:C60-PCBM layer and device performances.
关键词： photovoltaics cells,Bulk-heterojunction,P3HT:C60-PCBM solar cells
更新于2025-09-23 15:21:01
-
Improved performance of small molecule organic solar cells by incorporation of a glancing angle deposited donor layer
摘要： improving the photovoltaic performance directly by innovative device architectures contributes much progress in the field of organic solar cells. Photovoltaic device using different kinds of heterojunction with the given set of organic semiconductors paves the way to a better understanding of the working mechanism of organic heterojunction. Here, we report on the fabrication of a new device structure without employing extra material. A thin film of the donor material (chloroaluminum phthalocyanine (ClAlPc)) is inserted between ClAlPc:C60 bulk heterojunction (BHJ) and C60 layer by glancing angle deposition. A ClAlPc/C60 planar heterojunction co-exists with ClAlPc:C60 BHJ simultaneously in this device. Higher efficiency is obtained with this novel device structure. The effects of this additional ClAlPc layer on open-circuit voltage and fill factor in photovoltaic cells are studied. This work provides a new route to improve the device performance of organic solar cells.
关键词： glancing angle deposition,bulk heterojunction,donor layer,organic solar cells,photovoltaic performance
更新于2025-09-23 15:21:01