- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Improved charge transfer, mobility and morphology for high performance panchromatic organic photodetectors by adding PC71BM in P3HT:IEICO-4F
摘要： High performance of panchromatic organic photodetectors (OPDs) with a wide spectral response ranged from 300 to 1000 nm were realized through adding [6,6]-phenyl-C71-butyric acid methylester (PC71BM) fullerene as an electron acceptor into the polymer donor of poly (3-hexylthiophene) (P3HT) and the small molecular non-fullerene acceptor of 2, 2′-((2Z,2′Z)-(((4, 4, 9, 9-tetrakis(4-hexylphenyl)-4, 9-dihydro-sindaceno[1, 2-b:5, 6-b′] dithiophene-2, 7-diyl)bis(4-((2-ethylhexyl)oxy)thiophene-5, 2-diyl))bis-(methanylylidene))bis(5, 6-di?uoro-3-oxo-2, 3-dihydro-1H-indene-2, 1-diylidene))dimalononitrile (IEICO-4F) host system. The fabricated OPD exhibited a high detectivity (D*) of 1.35 × 1012 Jones at 805 nm by adding 10 wt% PC71BM, which is 1.5 folds higher than it from the control system. The improved performance was mainly attributed to the increased light absorption in the short wavelength range and cascade energy level alignment, which is responsible for the e?cient light harvesting and exciton utilization. Furthermore, the active layer morphology was optimized by adjusting the ratio of PC71BM acceptor, which e?ciently enhances charge transport and mobility of the device as well as suppress bimolecular recombination. This work indicates that adding fullerene into non-fullerene system plays a positive e?ect on the device performance of panchromatic OPDs.
关键词： Film morphology,Charge mobility,Non-fullerene and fullerene acceptors,Panchromatic organic photodetector,Charge transfer
更新于2025-09-11 14:15:04
-
Nonacyclic carbazole-based non-fullerene acceptors enables over 12% efficiency with enhanced stability for organic solar cells
摘要： In this work, a nonacyclic carbazole-cored electron-rich central building block called CZTT and its derivated non-fullerene acceptors (CZTT-IC and CZTT-4F) are designed and synthesized. CZTT-4F with fluorination on the accepting end groups shows significantly down-shifted energy levels and a narrower bandgap as well as a smaller dipole moment under the ground state in comparison to the counterpart CZTT-IC. In the blend films, blends of both fluorinated donor and acceptor (PM6:CZTT-4F) reveal relatively decreased miscibility resulting in better donor/acceptor interpenetrating network with higher domain purity for efficient charge transport. Organic solar cells (OSCs) based on PM6:CZTT-4F blend exhibited a highest power conversion efficiency (PCE) of 12.07% with enhanced thermal and light soaking stability. To the best of our knowledge, this performance is among the highest for carbazole-based OSCs in the literature. The results reveal that the nonacyclic CZTT core is a promising building block for constructing efficient non-fullerene acceptors. More importantly, the relatively decreased miscibility within fluorinated CZTT-based blend film is demonstrated to greatly promote the stability of OSCs.
关键词： stability,nonacyclic carbazole,non-fullerene acceptors,organic solar cells,power conversion efficiency
更新于2025-09-11 14:15:04
-
Evaluation of exciton diffusion length in highly oriented fullerene films of fullerene/p-Si(100) hybrid solar cells
摘要： Highly oriented fullerene (C60) films on p-Si (100) substrates were fabricated to evaluate the crystallinity dependent exciton diffusion length of C60 (LC60). The crystal structure of the C60 films was examined using grazing incidence X-ray diffraction (GIXD). The results of an in-plane rocking scan and a pole figure suggested that a 12-fold-symmetry crystal was grown with the C60(111) surface interfaced to the Si(100) substrate. The photovoltaic characteristics of the oriented C60/p-Si(100) hybrid solar cells were evaluated. A masking effect was clearly evident in the incident photon-to-current conversion efficiency (IPCE) spectra. LC60 was evaluated using both experimental IPCE spectra and that produced by one-dimensional-optical simulation. It was concluded that LC60 for highly oriented C60 was 60 nm, which was longer than that of disordered C60 films.
关键词： crystal growth,hybrid solar cells,fullerene (C60),exciton diffusion length,grazing incidence X-ray diffraction (GIXD),masking effect
更新于2025-09-11 14:15:04
-
Efficient Organic Solar Cells with a High Open‐Circuit Voltage of 1.34 V
摘要： One of the most important challenges that hinders the power conversion efficiencies (PCEs) of organic solar cells (OSCs) is the modest open-circuit voltages (VOC) due to large energy losses. The large driving force during for charge generation and the non-radiative recombination are the main causes of energy losses. To maximize the VOC of OSCs, herein, we modulate the end-groups and design a non-fullerene acceptor ITCCM-O, which shows a bandgap of 2.0 eV. By blending a polymer donor named J52, the device demonstrates a PCE of 5.5% with an outstanding VOC of 1.34 V, which is the highest value for single-junction OSCs over 5% PCEs. The high VOC is benefited from 1) the negligible driving force for charge transfer, and 2) the suppressed non-radiative recombination loss, as low as 0.22 V.
关键词： energy losses,high voltage,non-fullerene acceptors
更新于2025-09-11 14:15:04
-
Backbone Fluorination of Polythiophenes Improves Device Performance of Non-Fullerene Polymer Solar Cells
摘要： Polythiophenes (PTs) are promising donor materials for the industrialization of polymer solar cells (PSCs) due to the merits of easy synthesis, low cost, and large-scale producibility. The rapid progress of non-fullerene acceptors requires the development of new PTs for use in non-fullerene PSCs. In this work, we present a set of PTs with different degree of backbone fluorination (P6T-F00, P6T-F50, P6T-F75, and P6T-F100) to investigate the effect of fluorination on the photovoltaic properties of PTs in non-fullerene PSCs. Upon increasing fluorine content, the PTs tend to have higher crystallinity, higher absorption coefficients, and enhanced relative dielectric constants. When blended with a non-fullerene acceptor EH-IDTBR, the blend films show increased photoluminescence quenching efficiency, reduced charge recombination loss, and extended charge carrier lifetime along with increasing fluorine content of PTs. These positive factors collectively result in dramatically improved power conversion efficiency from 4.3% for P6T-F00:EH-IDTBR to 7.3% for P6T-F100:EH-IDTBR, which is superior to the champion binary non-fullerene PSCs based on P3HT. Our results demonstrate that PTs are promising donor materials for non-fullerene PSCs via backbone fluorination.
关键词： polythiophenes,polymer solar cells,backbone fluorination,dielectric constant,non-fullerene acceptors
更新于2025-09-11 14:15:04
-
Efficient non-fullerene polymer solar cells enabled by side-chain conjugated thieno[3,4-c]pyrrole-4,6-dione-based polymer and small molecular acceptors
摘要： The application of non-fullerene (NF) acceptors in bulk-heterojunction (BHJ) polymer solar cells (PSCs) is a promising approach to overcome the inherent drawbacks of fullerene derivatives-based acceptors. In PSCs, complementary absorption as well as matched molecular energy levels between the low bandgap acceptor-donor-acceptor (A-D-A) small molecular acceptor and medium/wide bandgap polymer donor is crucial to achieve high power conversion efficiency (PCE). Alternating polymers based on benzodithiophene (BDT) electron-donating segment and thieno[3,4-c]pyrrole-4,6-dione (TPD) electron-withdrawing segment own medium bandgap and low-lying highest occupied molecular orbital (HOMO) energy level, leading to presentable photovoltaic properties with fullerene derivatives. To probe into the performances of TPD-based polymers in NF-PSCs, two TPD-based polymers containing alkoxy or alkylthienyl modified benzo[1,2-b:4,5-b′]dithiophene (BDT) were synthesized and adopted as electron-donors and blended with A-D-A-type electron-acceptor 2,2′-[[6,6,12,12-tetrakis(4-hexylphenyl)-s-indacenodithieno[3,2-b]thiophene]methylidyne(3-oxo-1H-indene-2,1(3H)-diylidene)]]bis(propanedinitrile) (ITIC) to fabricate the corresponding photovoltaic devices. The two-dimensional conjugated polymer PBDTT-TPD shows enhanced extinction coefficient, deeper HOMO energy level and better hole transport performance, resulting in improved PCE of 6.17%. To further boost the performances of the polymers, a small molecular acceptor 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl) bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC) with down-shifted energy level was also used to blend with the two polymers in PSCs. Despite the open-circuit voltage (VOC) of the PBDTT-TPD:IDIC-based device is slightly decreased, the short-circuit current density (JSC) and fill factor (FF) are simultaneously improved, yielding an promising PCE of 7.15%. These results indicate that two-dimensional conjugated TPD-based polymers can be potential application as medium bandgap polymeric donor to match with small molecular acceptors having suitable molecular energy levels to get high efficiency in PSCs.
关键词： Non-fullerene acceptors,Thieno[3,4-c]pyrrole-4,6-dione,Energy level offsets,Polymer solar cells,Thermal annealing
更新于2025-09-11 14:15:04
-
Highly Selective and Scalable Fullerene-Cation-Mediated Synthesis accessing Cyclo[60]fullerenes with 5-Membered-Carbon-Ring and their Application to Perovskite Solar Cells
摘要： Cyclo[60]fullerenes are widely used in many applications including photovoltaic devices owing to their high electron affinity and mobility for an organic molecule. However, their synthesis has been limited to certain derivatives with low yields. In this work, a fullerene-cation-mediated synthesis, accessing a new class of 5-membered-carbon-ring cyclo[60]fullerenes with high yields of up to 93% is showcased. This method utilizes aryl[60]fullerene cations, ArC60+ as intermediates, which are generated in situ by heating the aryl[60]fullerenyl dimers in the presence of CuBr2. In addition, 5-membered-carbon-ring cyclo[60]fullerenes display excellent device applicability when they are used in perovskite solar cells as over-coating layers of electron-transporting layers. A power conversion efficiency of 20.7% is achieved thanks to the favorable energy alignment, optimized substrate design, and electrochemical stability of the 5-membered-carbon-ring fullerenes.
关键词： fullerene-cation-mediated synthesis,perovskite solar cells,5-membered-carbon-ring,cyclo[60]fullerenes,power conversion efficiency
更新于2025-09-11 14:15:04
-
Intrinsic Photo-degradation and Mechanism of Polymer Solar Cells: The crucial role of Non-fullerene Acceptor
摘要： The performances of polymer solar cells (PSCs) based on non-fullerene acceptors (NFAs) have improved remarkably in recent years, but such devices are insufficiently stable for practical applications. Here, we investigated the effects of NFAs on PSC long-term stability. We found that high performance PBDB-T:ITIC solar cells exhibit much lower stability than PTB7:PC71BM devices in the 1 sun light-soaking test; when compared with their initial performances, the performance of PTB7:PCBM-based solar cells remains above 60% for over 4000 h, whereas that of PBDB-T:ITIC-based devices is reduced to one fifth after 1000 h. We demonstrated that the ITIC-based PSCs exhibit poor photo-stability because ITIC at the interface of the ZnO/active film is readily decomposed by a photocatalytic reaction; this poor stability arises because the vinyl group of ITIC is chemically more vulnerable than the stable aromatic units in the organic active materials. The decomposition of ITIC results in the degradation of the electron transport properties of the active materials located close to ZnO, which leads to severe burn-in degradation and reduced FF and VOC under illumination. It is thus highly important to develop intrinsically stable organic materials composed of chemically stable building blocks in order to realize stable and high efficiency PSCs.
关键词： polymer solar cells,photocatalytic reaction,non-fullerene acceptors,photo-stability,ITIC
更新于2025-09-11 14:15:04
-
Effect of fullerene substituent on thermal robustness in polymer:fullerene bulk heterojunction solar cells
摘要： Effect of fullerene substituent on thermal robustness in polymer:fullerene bulk heterojunction solar cells using a conjugated polymer PTB7-Th. While 175 °C is the best annealing temperature for a solar cell with unmodified C70, it deteriorates a device with a substituted C70 (C70-PCBM). Additionally, annealing at 175 °C does not change the surface of PTB7-Th:C70 film but makes the surface of PTB7-Th:C70-PCBM film bumpy. The results suggest that the substituent promotes the migration of fullerene in polymer:fullerene solid composite.
关键词： fullerene,C70-PCBM,PTB7-Th,bulk heterojunction solar cells,thermal robustness
更新于2025-09-11 14:15:04
-
Building Blocks for High‐Efficiency Organic Photovoltaics: Interplay of Molecular, Crystal, and Electronic Properties in Post‐Fullerene ITIC Ensembles
摘要： Accurate single-crystal X-ray diffraction data offer a unique opportunity to compare and contrast the atomistic details of bulk heterojunction photovoltaic small-molecule acceptor structure and packing, as well as provide an essential starting point for computational electronic structure and charge transport analysis. Herein, we report diffraction-derived crystal structures and computational analyses on the n-type semiconductors which enable some of the highest efficiency organic solar cells produced to date, 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b’]dithiophene (ITIC) and seven derivatives (including three new crystal structures: 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-propylphenyl)-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b’]dithiophene (ITIC-C3), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(3-hexylphenyl)-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b’]dithiophene (m-ITIC-C6), and 3,9-bis(2-methylene-((3-(1,1-dicyanomethylene)-6,7-difluoro)-indanone))-5,5,11,11-tetrakis(4-butylphenyl)-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b’]dithiophene (ITIC-C4-4F). IDTT acceptors typically pack in a face-to-face fashion with π–π distances ranging from 3.28–3.95 ?. Additionally, edge-to-face packing is observed with S?π interactions as short as 3.21–3.24 ?. Moreover, ITIC end group identities and side chain substituents influence the nature and strength of noncovalent interactions (e.g. H-bonding, π–π) and thus correlate with the observed packing motif, electronic structure, and charge transport properties of the crystals. Density functional theory (DFT) calculations reveal relatively large nearest-neighbor intermolecular π-π electronic couplings (5.85–56.8 meV) and correlate the nature of the band structure with the dispersion interactions in the single crystals and core–end group polarization effects. Overall, this combined experimental and theoretical work reveals key insights into crystal engineering strategies for indacenodithienothiophene (IDTT) acceptors, as well as general design rules for high-efficiency post-fullerene small molecule acceptors.
关键词： density functional calculations,crystal structure,non-fullerene,molecular modelling,solar cells
更新于2025-09-11 14:15:04