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Semiconducting carbon nanotubes in photovoltaic blends: The case of pTB7:PC <sub/>60</sub> BM:(6,5) SWNT
摘要： Blends of carbon nanotubes with conjugated polymer and fullerene derivatives are complex nanocomposite systems, which have recently attracted great research interest for their photovoltaic ability. Therefore, gaining a better understanding of the excitonic dynamics in such materials can be important to boost the efficiency of excitonic solar cells. Here, we studied the photophysics of a ternary system in which the polymer PTB7 and the fullerene derivative PCBM are integrated with (6,5) single walled carbon nanotubes. We highlight the contribution of SWNTs in the exciton dissociation and in the charge transfer process. These findings can be useful for the exploitation of these multi-component systems for organic photovoltaic and, in general, optoelectronic applications.
关键词： excitonic dynamics,PCBM,photovoltaic blends,PTB7,SWNTs,carbon nanotubes
更新于2025-10-22 19:40:53
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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
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Polythiophene–PCBM-Based All-Organic Electrochromic Device: Fast and Flexible
摘要： A fast and ?exible all-organic electrochromic device, fabricated using polythiophene and PCBM as active materials and plastic substrate, which shows very good power e?ciency as well, has been reported here. The device shows quanti?able improvement in electrochromic performance using parameters like switching speed, coloration e?ciency, color contrast, and cycle life. Spectroscopic investigations have been carried out using Raman and UV?vis to establish a bias induced redox switching based mechanism for the reported improvement in the performance. The device shows switching between magenta (OFF) and transparent states (ON) with a very small bias of ±1 V, an optical modulation of 50% and an absorbance switching contrast of 91%. An enhanced stability for a duration of longer than 2500 s and 250 cycles has been reported with an ultrafast response of few hundred milliseconds. A very high coloration e?ciency of 321 cm2/C is achieved, making the proposed device one of the best reported P3HT-based electrochromic devices.
关键词： PCBM,electrochromic,polythiophene,?exible devices,organic electronics
更新于2025-09-23 15:22:29
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Influence of blending ratio on resistive switching effect in donor-acceptor type composite of PCBM and PVK-based memory devices
摘要： The influence of blending ratio on resistive switching effect in donor-acceptor type composite of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly(N-vinylcarbazole) (PVK)-based memory devices are investigated. Current-voltage (I-V) curves for the ITO/PCBM + PVK/Al devices with 9 wt.% of PCBM showed a current bistability with a maximum OFF/ON resistance ratio of 9 × 104, which was 100 times larger than that of the device with 23 wt.% of PCBM and was 2000 times larger than that of the device with 41 wt.% of PCBM. Furthermore, the threshold voltage obviously decreased as the PCBM concentration increases. The retention time was above 105 s indicative of the memory stability of the as-fabricated devices. The I-V characteristics at OFF state dominantly comply with the rules of space-charge-limited-current behaviors, and I-V curve at ON state obey Ohmic laws. The proposed device suggests a promising approach for adjustale OFF/ON resistance ratio and threshold voltage in electronic memory devices.
关键词： Nonvolatile memory,Resistive switching,PVK,Organic memory,PCBM
更新于2025-09-23 15:21:21
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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
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[IEEE 2019 12th International Conference on Developments in eSystems Engineering (DeSE) - Kazan, Russia (2019.10.7-2019.10.10)] 2019 12th International Conference on Developments in eSystems Engineering (DeSE) - The Effects of Al-Doped ZnO Layer on the Performance of Organic Solar Cell
摘要： The interface properties as well as the solar cell properties of inverted organic solar cells based on PCDTBT:PCBM blends were investigated using sol-gel aluminum doped ZnO as electron transport layers. The effects of Al concentration on the optical, structural and morphological properties of AZO layer were investigated. The results indicate that Al concentration has influenced the grain size growth leading to different surface morphology. High doping concentration resulted in higher charge carrier density and wider band gap. Using AZO layers in organic solar cell has increased their performance; the best performance was observed for the device with 0.5% Al-doped ZnO layer with efficiency of 3.24%, short circuit current density of 8.82mA.cm-2, fill factor of 0.46% and open circuit voltage of 0.81V, whereas the reference device has exhibited an efficiency of 2.9%, short circuit current density of 7.6mA.cm-2, fill factor of 0.48 % and open circuit voltage of 0.785V.
关键词： Electron Transport layer,PCDTBT:PCBM,Organic solar cell,AZO thin films
更新于2025-09-23 15:21:01
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Role of PCBM in the Suppression of Hysteresis in Perovskite Solar Cells
摘要： The power conversion efficiency of inorganic–organic hybrid lead halide perovskite solar cells (PSCs) is approaching that of those made from single crystalline silicon; however, they still experience problems such as hysteresis and photo/electrical-field-induced degradation. Evidences consistently show that ionic migration is critical for these detrimental behaviors, but direct in-situ studies are still lacking to elucidate the respective kinetics. Three different PSCs incorporating phenyl-C61-butyric acid methyl ester (PCBM) and a polymerized form (PPCBM) is fabricated to clarify the function of fullerenes towards ionic migration in perovskites: 1) single perovskite layer, 2) perovskite/PCBM bilayer, 3) perovskite/PPCBM bilayer, where the fullerene molecules are covalently linked to a polymer backbone impeding fullerene inter-diffusion. By employing wide-field photoluminescence imaging microscopy, the migration of iodine ions/vacancies under an external electrical field is studied. The polymerized PPCBM layer barely suppresses ionic migration, whereas PCBM readily does. Temperature-dependent chronoamperometric measurements demonstrate the reduction of activation energy with the aid of PCBM and X-ray photoemission spectroscopy (XPS) measurements show that PCBM molecules are viable to diffuse into the perovskite layer and passivate iodine related defects. This passivation significantly reduces iodine ions/vacancies, leading to a reduction of built-in field modulation and interfacial barriers.
关键词： perovskites,ion migration,J–V curve hysteresis,PCBM
更新于2025-09-23 15:21:01
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Hybrid P3HT: PCBM/GaN nanowire/Si cascade heterojunction for photovoltaic application
摘要： Poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) are commonly used for the fabrication of organic photovoltaics (OPV). Efficiency limitations of OPVs could be circumvented by incorporation of inorganic nanostructures into organic blends. Again, integration of organic solar cells with well-developed silicon photovoltaic technology is ultimately desirable. In the present work, GaN nanowires with diameters of 25–50 nm and two lengths (200 and 500 nm) have been grown using molecular beam epitaxy technique. Solar-grade monocrystalline silicon wafers were used as substrates for nanowire synthesis. GaN nanostructures were incorporated into P3HT:PCBM photoactive layer in order to facilitate charge transfer between P3HT:PCBM and Si. Samples with and without nanowires were compared. Addition of nanowires led to the improvement in photovoltaic performance. Open circuit voltage has risen by 72% and short circuit current density by 200%. Series resistance has decreased 50 times, and power conversion efficiency has risen 20.7 times. Additional maxima are found in photocurrent spectrum corresponding to carriers being generated near GaN absorption edge. Moreover, external quantum efficiency peaks near GaN absorption edge, indicating transfer channel via the formation of current P3HT/GaN/Si cascade heterojunction. Mechanism explaining source of abovementioned improvement is proposed.
关键词： Molecular beam epitaxy,Energy conversion,P3HT,Solar cells,PCBM,GaN nanowires
更新于2025-09-23 15:21:01
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The influence of fullerene on hysteresis mechanism in planar perovskite solar cells
摘要： Despite the rapid development of perovskite devices, the current density-voltage hysteresis still needs to be conquered. Here, the introduction of PCBM into the active layer of planar perovskite solar cells is carried out and hysteresis-free devices are produced. A photoluminescence blue-shift in PCBM-doped perovskite ?lms is observed. The e?ect of non-radiative recombination is obviously suppressed, and the photoluminescence lifetime is signi?cantly prolonged by 3-fold after PCBM introduction. The roles of PCBM in trap states and hysteresis mechanism are also discussed. This research could provide experimental and theoretical supports for suppressing and eliminating the hysteresis phenomena in perovskite solar cells.
关键词： Hysteresis,Trap states,Planar perovskite solar cells,PCBM
更新于2025-09-23 15:19:57
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The diverse passivation effects of fullerene derivative on hysteresis behavior for normal and inverted perovskite solar cells
摘要： [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is usually used to passivate the trap states and ion defects for suppressing hysteresis in both normal and inverted perovskite solar cells. Here, we find that the normal cell with the perovskite film fabricated on the PCBM film shows an evident hysteresis, while the inverted cell with the perovskite film covered by the PCBM film shows nearly no hysteresis, and the PCBM-Perovskite interface impacts on the hysteresis vastly. The poor PCBM surface wettability results in an inefficient carrier extraction at the interface and a red-shift of photoluminescence emission for the perovskite film coated on the PCBM film, which results from the plentiful trap states and ion defects inside the perovskite film due to its poor crystallization. Thus, the trapping/de-trapping processes and slow ion migration eventually lead to the hysteresis. For the perovskite film covered by the PCBM film, due to the good wettability of the perovskite film, PCBM molecules easily permeate into the perovskite film to passivate the trap states and ion defects, which improves the carrier extraction and thus eliminates the hysteresis of the inverted cell.
关键词： Hysteresis behavior,Trap states,Perovskite solar cells,Ion migration,Carrier extraction,PCBM
更新于2025-09-23 15:19:57