- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Cathode Interface Engineering Approach for a Comprehensive Study of the Indoor Performance Enhancement in Organic Photovoltaic
摘要： Organic photovoltaic (OPV) has a prospective future as a reliable energy harvesting to drive low power consumption devices for indoor applications. In this article, the outdoor (1 sun) and indoor (LED 2700K) performance of PTB7-Th:PC70BM inverted OPV with three different solution-processed electron transport layers (ETL = PFN, TiOx, and ZnO) were compared. The morphology, optical, and electrical measurements indicate the strong dependency of the OPV performance with the illumination conditions. The sample with PFN-ETL that shows the highest outdoor performance with power conversion efficiency (PCE) of 10.55% and the best-reported fill factor (FF) of 75.00% among PTB7-Th:PC70BM-based OPV, surprisingly exhibits the lowest performance when illuminated under 250–2000 lux LED 2700K. Meanwhile, the lowest outdoor performance performed by ZnO with PCE of 10.03% displays the best indoor performance with the PCE of 13.94% under 1000 lux and a PCE of up to 16.49% under 1750 lux LED lamp, respectively. The changes in the FF values can be estimated by incorporating the parasitic resistance effect due to the type ETL used. Besides, using impedance spectroscopy, we observed that indoor performance agreed well with the trend of charge collection efficiency.
关键词： impedance spectroscopy,Organic photovoltaic,electron transport layers,PTB7-Th:PC70BM,indoor performance
更新于2025-09-23 15:21:01
-
Modification of Hole Transport Layers for Fabricating High Performance Nona??fullerene Polymer Solar Cells
摘要： Interfacial engineering is expected to be a feasible strategy to improve the charge transport properties of the hole transport layer (HTL), which is of crucial importance to boosting the device performance of organic solar cells (OSCs). In this study, two types of alcohol soluble materials, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) and di-tetrabutylammoniumcis–bis(isothiocyanato)bis(2,2’-bipyridyl-4,4’-dicarboxylato) ruthenium (II) (N719) dye were selected as the dopant for HTL. The doping of F4-TCNQ and N719 dye in poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with and without integrating a graphene quantum-dots (G-QDs) layer has been explored in poly[[2,6′-4-8-di(5-ethylhexylthienyl)benzo[1,2-b:3,3-b]dithiophene][3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thio-phenediyl:(2,2′-((2Z,2′Z)-(((4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(4-((2-ethylhexyl)oxy)thiophene-5,2-diyl))bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (PTB7-Th:IEICO-4F) OSCs. The power conversion efficiency of the non-fullerene OSCs has been increased to 10.12% from 8.84%. The influence of HTL modification on the nano-morphological structures and photophysical properties is analyzed based on the comparative studies performed on the control and modified devices. The use of chemical doping and bilayer strategy optimizes the energy level alignment, nanomorphology, hole mobility, and work-function of HTL, leading to considerable reduction of the leakage current and recombination losses. Our work demonstrates that the doping of HTL and the incorporation of G-QDs layer to constitute a bilayer HTL is an promising strategy to fabricate high performance non-fullerene polymer solar cells.
关键词： UPS,PTB7-Th:IEICO-4F,atomic force microscopy,XPS,Organic solar cells
更新于2025-09-23 15:21:01
-
Effects of non-halogenated solvent on the main properties of a solution-processed polymeric thin film for photovoltaic applications: a computational study
摘要： Organic photovoltaic (OPV) devices reached high solar conversion efficiencies but they are usually processed using halogenated toxic solvents. Hence, before OPV devices can be mass-produced by industrial processing, it would be desirable to replace those solvents with eco-friendly ones. Theoretical tools may be then a powerful ally in the search for those new solvents. In order to better understand the mechanisms behind the interaction between solvent and polymer, classical molecular dynamics (MD) calculations was used to produce a thin film of poly(4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl (PTB7-Th), processed using two different solvents. The PTB7-Th is widely applied as a donor material in OPVs. The first solvent is the ortho-dichlorobenzene (o-DCB), which is a highly toxic solvent widely used in lab-scale studies. The second solvent is the ortho-methylanisole (o-MA), which is an eco-friendly solvent for organic photovoltaic (OPV) manufacturing. Here we use a solvent evaporation protocol to simulate the formation of the PTB7-Th film. We demonstrate that our theoretical MD calculations were able to capture some differences in macroscopic properties of thin films formed by o-DCB or o-MA evaporation. We found that the interaction of the halogenated solvent with the polymer tends to break the bonds between the lateral thiophenediyl groups and the main chain. We show that those defects may create traps that can affect the charge transport and also can be responsible for a blue shift in the absorption spectrum. Using the Monte Carlo method, we also verified the influence of the resulting MD morphology on the mobility of holes. Our theoretical results showed a good agreement with the experimental measurements and both demonstrate that o-MA can be used to make polymer thin films without any loss of key properties for the device performance. The findings here highlights the importance of theoretical results as a guide to the morphological optimization of green processed polymeric films.
关键词： Solvent evaporation,PTB7-Th,Molecular dynamics,Organic photovoltaic,Halogenated solvents,Eco-friendly solvents,Hole mobility
更新于2025-09-23 15:19:57
-
Performance enhancement of conjugated polymer-small molecule-non fullerene ternary organic solar cells by tuning recombination kinetics and molecular ordering
摘要： We present our study of conjugated polymer-small molecule (SM)-non-fullerene ternary organic solar cells (OSCs), which employs conjugated polymer PTB7-Th and small molecule p-DTS(FBTTh2)2 as donors and non-fullerene molecule IEICO-4F as an acceptor. It is observed that the power conversion efficiency (PCE) of ～10.9% for PTB7-Th: p-DTS(FBTTh2)2: IEICO-4F ternary OSCs with 15 wt% of p-DTS(FBTTh2)2 SM is higher than PCE of ～9.8% for PTB7-Th: IEICO-4F OSCs. Morphological studies confirm that the addition of p-DTS(FBTTh2)2 SM in PTB7-Th: IEICO-4F binary blend improves molecular ordering and crystallinity of PTB7-Th due to the favorable interaction with p-DTS(FBTTh2)2 thereby providing 3-D textured structures consisting of a mixture of edge-on and face-on orientations. The improved molecular ordering is shown to enhance exciton generation rate, exciton dissociation, charge collection, and to reduce charge recombination, all of which boosts the PCE.
关键词： PTB7-Th,Ternary,p-DTS(FBTTh2)2,IEICO-4F,GIWAXS,Non-fullerene
更新于2025-09-23 15:19:57
-
Enhanced Efficiency and Stability of Nonfullerene Ternary Polymer Solar Cells Based on Spontaneously Assembled Active Layer: The Role of a High Mobility Small Molecular Electron Acceptor
摘要： It is challenging to afford efficient and stable organic solar cells based on the as-cast active layer without any external treatments. We present a planar organic electron acceptor BPTCN with high electron mobility as a third component in nonfullerene ternary polymer solar cells, which comprises an electron-deficient 4,7-bis(5H-4,6-dioxothieno[3,4-c]pyrrol-1-yl)benzo[c][1,2,5]thiadiazole core, doubly endcapped by 2-(3-ethyl-5-methylene-4-oxothiazolidin-2-ylidene)malononitrile through the alkylated thiophene-2,5-ylene unit. It shows a π-π stacking distance of 3.60 ? and μe of 1.31 × 10?3 cm2 V?1 s?1. BPTCN exhibits an absorption maximum at 569 nm in the as-cast film and good miscibility with the NIR-absorption acceptor COi8DFIC, leading to complete f?rster energy transfer in the blends. Adding BPTCN into the PTB7-Th:COi8DFIC blend produces multiple beneficial effects: i) facilitating exciton dissociation and charge transfer at the donor/acceptor interface while suppressing bimolecular and trap-assisted recombination by analysis of the Jph–Veff, Jsc–Ilight and Voc–Ilight characteristics, ii) increasing hole and in particular electron transport; and iii) generally promoting the crystallinity of the polymer donor PTB7-Th, as revealed by grazing incidence X-ray diffraction. Moreover, the phase purity is greatly improved in the ternary blend PTB7-Th:COi8DFIC:BPTCN (1:1.05:0.45 by weight). Consequently, the tentatively optimized ternary solar cell provides a PCE of 11.62% with Voc = 0.74 V, Jsc = 25.93 mA cm-2 and FF = 60.61% in comparison with the binary systems PTB7-Th:COi8DFIC (PCE of 9.41%) and PTB7-Th:BPTCN (6.42%) in the absence of any extra treatments. After thermal aging at 80 oC for 450 h, this ternary solar cell exhibits increased stability with PCE retaining 84.39% of the initial value.
关键词： PTB7-Th,COi8DFIC,BPTCN,electron acceptor,organic solar cells,thermal stability,nonfullerene ternary polymer solar cells
更新于2025-09-23 15:19:57
-
Design of parallel-connected polymer tandem solar cells using efficient low bandgap PTB7-Th:PC71BM blend
摘要： Parallel-connected tandem cells adopting a highly efficient donor polymer, PTB7-Th, combined with acceptor fullerene PC71BM as the back sub-cell was introduced to further improve the performance of polymer solar cells. Design of the device architecture was investigated using modeling and simulation methods based on the transfer matrix formalism. To optimize the device structure, detailed analysis of the effect of active layer thickness, different device structure, and transparent Ag intermediated electrode on the short-circuit current density has been studied. It was found the long-wavelength absorption in the top-illuminated ITO-free back cell was significantly enhanced due to the resonant microcavity effect, leading to an efficient utilization of the incident light and increased photocurrent. Giving these advantages, the power conversion efficiency of the parallel homo-tandem cell was estimated to be ~ 11%, which was ~ 15% higher than that of a single cell of PTB7-Th. Moreover, the maximum achievable current density and the corresponding optimum active layer thickness of the sub-cells varied a little as the thickness of ultrathin Ag layer was changed, indicating that parallel connection architecture provided more freedom in the design and optimization for high-performance tandem solar cells.
关键词： PC71BM,Polymer solar cells,Microcavity effect,Transfer matrix formalism,PTB7-Th,Parallel-connected tandem cells
更新于2025-09-12 10:27:22
-
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
-
Ultrasensitive Photoelectrochemical Assay with PTB7-Th/CdTe QDs Sensitized Structure as Signal Tag and 4-CD Precipitate as Efficient Quencher
摘要： Herein, an ultrasensitive photoelectrochemical (PEC) assay was developed for the monitoring of microRNA-141 (miRNA-141) based on poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)-carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7-Th)/CdTe quantum dots (CdTe QDs) sensitized structure as signal tag and the benzo-4-chloro-hexadienone (4-CD) precipitate as efficient quencher. PTB7-Th and CdTe QDs were successively modified on electrode surface to form a novel sensitized structure with eminent photovoltaic performances and surpassing film-forming ability. The PTB7-Th/CdTe QDs sensitized structure was served as signal tag for achieving a strong initial PEC signal. Besides, a tiny amount of target (miRNA-141) could be transformed into numerous DNA product via enzyme-assisted target cycling procedure, which further triggered the formation of DNA supersanwich structure on electrode surface for loading abundant manganese porphyrin (MnPP). Thereafter, MnPP as mimetic enzyme could catalyze 4-chloro-1-naphthol (4-CN) to generate 4-CD precipitate on sensing interface in the presence of H2O2, which could efficiently block electron transfer, leading to a significantly quenched PEC signal for determination of miRNA-141. The designed PEC biosensor performed a wide detection range from 0.1 fM to 1 nM with a low detection limit of 33 aM for miRNA-141, which paved a new avenue for highly accurate and ultrasensitive monitoring of multifarious analytes in bioanalysis and clinical diagnosis.
关键词： 4-CD precipitate,photoelectrochemical assay,ultrasensitive monitoring,miRNA-141,PTB7-Th/CdTe QDs,signal tag
更新于2025-09-10 09:29:36
-
Planar capacitive type humidity sensor fabricated using PTB7-Th by facile solution processing approach
摘要： A capacitive humidity sensor using coplanar electrodes coated with poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl](PTB7-Th) thin film (Al/PTB7-Th/Al) has been fabricated and investigated. In the present work, we show that increased sensitivity is obtained by rough and non-uniform surface morphology of the polymer thin film which comprises distinct peaks and valleys. The sensor shows good sensing behavior with enhanced sensitivity, better linearity and larger bandwidth. The device showed sensitivity over an appreciable range of relative humidity levels (between 20 and 95% RH). Typical adsorption and desorption response times were measured to be 20 s each.
关键词： Sensitivity,Bandwidth,Linearity,PTB7-Th,Solution processing,Capacitive humidity sensor
更新于2025-09-04 15:30:14