共查询到20条相似文献,搜索用时 15 毫秒
1.
Degradation of organic solar cells due to air exposure 总被引:1,自引:0,他引:1
Kenji Kawano Roberto Pacios Dmitry Poplavskyy Jenny Nelson Donal D.C. Bradley James R. Durrant 《Solar Energy Materials & Solar Cells》2006,90(20):3520-3530
We present a study of dark air-exposure degradation of organic solar cells based on photoactive blends of the conjugated polymer, poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene] (MDMO-PPV) with [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Photovoltaic devices were fabricated on indium tin oxide (ITO) glass with or without a layer of poly (3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS), and were studied without encapsulation. Photovoltaic performance characteristics were measured as a function of time for different ambient conditions (under white light irradiation and in the dark, and under air, dry oxygen and humid nitrogen atmospheres). It was found that a key cause of degradation under air exposure is light independent and results from water adsorption by the hygroscopic PEDOT:PSS layer. Measurements of the charge mobility and hole injection after air exposure showed that the degradation increases the resistance of the PEDOT:PSS/blend layer interface. 相似文献
2.
W. BagienskiM.C. Gupta 《Solar Energy Materials & Solar Cells》2011,95(3):933-941
The temperature dependence of bulk heterojunction organic solar cells fabricated from poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was studied in detail. Individual materials as well as blends and solar cell devices were examined. Light absorption, photoluminescence, quantum efficiency, total efficiency, and current-voltage characteristics were studied from temperatures −10 to 140 °C. A method and apparatus for testing these parameters at various temperatures is described. Parameters were measured for both unannealed and annealed samples to give insight into the annealing process. It was found that absorption and photoluminescence of devices shift both position and intensity with varying temperatures. Quantum efficiency and total efficiency were monitored as they increased with annealing. Once annealed, device efficiency peaked at temperatures from 10 to 60 °C because of competing temperature dependent effects of the materials. The temperature dependence study provides valuable information on device properties and thermal annealing. 相似文献
3.
Soon Ok JeonJun Yeob Lee 《Solar Energy Materials & Solar Cells》2011,95(4):1102-1106
The high temperature stability of the organic solar cells (OSCs) was improved using a phosphine oxide based organic cathode modification layer instead of LiF. The OSC modified with the phosphine oxide cathode modification layer showed constant device performances after a thermal treatment at 90 °C, while the LiF based OSC exhibited degraded device performance after the thermal treatment. The use of the phosphine oxide based interlayer was effective to improve the high temperature stability of the OSC. 相似文献
4.
Effect of solvent on fabrication of active layers in organic solar cells based on poly(3-hexylthiophene) and fullerene derivatives 总被引:2,自引:0,他引:2
Investigating the effect of solvent on the fabrication of photo-active layers in bulk heterojunction organic solar cells based on poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyl ester, we found the short-circuit current density (JSC) and fill factor (FF) of a cell with a photo-active layer made using materials dissolved in a mixture of o-dichlorobenzene with chloroform to be slightly higher than those of a cell made using the same materials dissolved only in chlorobenzene. Evaluating the absorption spectra, surface morphology, charge mobility, and solubility of photo-active films made using different solvents, we concluded that the higher JSC and FF were due to a larger interfacial area between the photo-active materials in the layer. 相似文献
5.
Pingli Qin Guojia Fang Wei ZengXi Fan Qiao ZhengFei Cheng Jiawei WanXingzhong Zhao 《Solar Energy Materials & Solar Cells》2011,95(12):3311-3317
Organic solar cells (OSCs) based on the blends of poly(3-hexylthiophene) and fullerene derivative [6, 6]-phenyl-C61 butyric acid methyl ester have been fabricated with p-type chromium oxide film as hole-transporting layer. The distribution of temperature and heat flow in vacuum chamber was investigated by temperature probes and finite element method. It is found that the two factors have significant effect on the quality of the thermally evaporated Al cathode. The bigger momentum impinging Al particles facilitates the formation of C-Al or C-O-Al bonds at the interface between photoactive layer and Al electrode, which is propitious to the electron transfer, and the corresponding devices have higher electron mobility. The higher substrate temperature that induced by thermal radiation during Al evaporation can act as a function of thermal annealing treatment, which can eliminate some electron traps and lead to better ohmic contacts for electrons to transport at the interface. The combination of the bigger momentum impinging Al particles and the higher substrate temperature can induce the improvement of electron mobility and OSC performance. 相似文献
6.
Matthieu Manceau Agnès Rivaton Jean-Luc Gardette Stéphane GuillerezNoëlla Lemaître 《Solar Energy Materials & Solar Cells》2011,95(5):1315-1325
We report on the effects of long-term artificial accelerated ageing on the active layer of organic solar cells in the absence of oxygen. The samples were composed of a bulk heterojunction formed by poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) deposited on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). First, a set of experiments was performed to study the modifications resulting from prolonged exposure to UV-vis light. A gradual decrease in absorbance was recorded, and TEM results clearly indicated that the initial morphology was unstable upon long irradiation times. Second, we revealed that the annealing temperature of PEDOT:PSS strongly influenced the degradation of the active layer. Indeed, an increase in the PEDOT:PSS annealing temperature resulted in an important improvement in stability. Third, a comparison was made between different active layers obtained by changing the P3HT type, polymer:fullerene weight ratio and solvent nature. As expected, the polymer:fullerene weight ratio was shown to significantly impact the degradation kinetics. The ageing effects on the photovoltaic properties were then explored, and extrapolation of the data to outdoor exposure is also discussed. 相似文献
7.
Rui Jie PehYanru Lu Fangli Zhao Chi-Lik Ken Lee 《Solar Energy Materials & Solar Cells》2011,95(12):3579-3584
Spray coating is a high throughput coating technique that is scalable and adaptable for organic photovoltaic manufacturing. To ensure uniform coating of the organic layers, the wettability, surface tension and boiling points of the solvents have to be optimized. Here, we used microscopic videos to understand the dynamics of the spray coating process. By optimizing the wettability and drying time of the PEDOT:PSS suspension on a hydrophobic surface, we attained a spray coated transparent anode without compromising on device performance. We further applied this vacuum-free process to a near infrared absorber to achieve a transparent organic solar cell with close to 60% transparency. 相似文献
8.
Florent Monestier Jean-Jacques Simon Philippe Torchio Ludovic Escoubas Franois Flory Sandrine Bailly Remi de Bettignies Stephane Guillerez Christophe Defranoux 《Solar Energy Materials & Solar Cells》2007,91(5):405-410
We have investigated the short-circuit current density of organic solar cells based on poly (3-hexylthiophene)(P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. In order to model charge collection efficiencies with respect to short circuit density in such blends, a full optical modeling of the cell is performed. From the distribution of the electromagnetic field, we compute the rate of exciton generation. This exciton generation rate is used as input in the transport equations of holes and electrons. Charge densities at steady state are obtained as solutions are used for computing short-circuit current densities generated in the cell. The dependence of short-circuit current densities versus the thickness of the blend is analyzed and compared with our experimental data and with data extracted from the literature. 相似文献
9.
Yang ShenKejia Li Nabanita MajumdarJoe C. Campbell Mool C. Gupta 《Solar Energy Materials & Solar Cells》2011,95(8):2314-2317
In this paper, the series resistance of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) organic solar cells (OSC) has been studied. The series resistance of thermal annealed and un-annealed devices with different active layer thicknesses was measured. The series resistance of the organic solar cells consists of the bulk resistance of the active layer itself and the specific contact resistance between the active layer and the electrode. The bulk resistance and contact resistance were extracted from the measured series resistance using the vertical transmission line model (TLM) method. By fabricating solar cell devices with different active layer thicknesses, a relationship of the series resistance with thickness was established from which bulk and contact resistances were derived. We have also found that thermal annealing helps reduce both contact resistance and bulk resistance significantly; the contact resistance dropped by a factor of 2, while the bulk resistance decreased by a factor of 8. Results have shown that for an annealed P3HT:PCBM device that has an active layer thickness of 85 nm (optimum thickness for high efficiency), 17% of the total series resistance was due to the contact resistance, and bulk resistance contributed the rest 83%. The bulk resistance value for thermal annealed organic solar cell device with an active area of 0.1 cm2 was found to be 150 Ω, and the measured specific contact resistance was 3.1 Ω cm2. The measured bulk and contact resistance values are much higher as compared to the high efficiency silicon solar cells. Bulk resistance and contact resistance need to be further decreased in order to achieve higher organic solar cell efficiency. 相似文献
10.
A new model is developed by combining the optical model and the drift-diffusion model to optimize the thicknesses of active layers of individual sub-cells for high performance of organic tandem solar cell. When the photovoltaic properties of tandem organic solar cells based on poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta (2,1-b;3,4-b′) dithiophene)-alt-4,7-(2,1,3-benzo-thiadiazole))/(6,6)-phenyl C71-butyric acid methyl ester and poly(3-hexylthiophene)/(6,6)-phenyl C61-butyric acid methyl ester are calculated as functions of thicknesses of individual sub-cells using the new model, it is found that the optimum thickness pair of active layers is 150 and 120 nm for the front and back sub-cell, respectively. Comparison of simulation with experiment reveals that the simulated results are very consistent with experimental ones. 相似文献
11.
Gwan Ho Jung Kyung-Geun LimTae-Woo Lee Jong-Lam Lee 《Solar Energy Materials & Solar Cells》2011,95(4):1146-1150
An ultrathin iridium layer was treated with O2-plasma to form an iridium oxide (IrOx), employed as a hole extraction layer in order to replace poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) in organic photovoltaic (OPV) cells with poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM). The IrOx layer affects the self-organization of the P3HT:PCBM photo-active layer due to its hydrophobic nature, inducing a well-organized intraplane structure with lamellae oriented normal to the substrate. Synchrotron radiation photoelectron spectroscopy results showed that the work function increased by 0.57 eV as the Ir layer on ITO changed to IrOx by the O2-plasma treatment. The OPV cell with IrOx (2.0 nm) exhibits increased power conversion efficiency as high as 3.5% under 100 mW cm−2 illumination with an air mass (AM 1.5G) condition, higher than that of 3.3% with PEDOT:PSS. 相似文献
12.
Jens A. Hauch Pavel Schilinsky Stelios A. Choulis Richard Childers Markus Biele Christoph J. Brabec 《Solar Energy Materials & Solar Cells》2008,92(7):727-731
Flexible organic solar cells and modules based on P3ht:PCBM bulk-heterojunctions were fabricated and their lifetime was investigated under laboratory and outdoor conditions. In the laboratory cells were exposed to 1 sun illumination at 65 °C in order to accelerate the degradation. The outdoor behavior of modules was investigated at the Konarka rooftop testing setup in Lowell, MA (USA). We show that these flexible polymer solar cells have a good light stability, passing 1000 h under accelerated light soaking conditions in the laboratory, and that flexible modules survived over 1 year of outdoor exposure without performance losses. 相似文献
13.
Qun Liang Song 《Solar Energy Materials & Solar Cells》2009,93(8):1394-1397
Photocurrent of an organic solar cell under chopped monochromatic light was studied at different stages, i.e. just after fabrication (without degradation) and after serious degradation. A large photocurrent under chopped light was observed for a seriously degraded device, unexpected from intuitionistic reckoning. This work demonstrates that both light bias and chopper frequency affect the photocurrent measurement of an organic solar cell, especially for a degraded device. The influence of light bias and chopper frequency is explained as the result of traps produced during the degradation of an organic solar cell. Thus measuring photocurrent under one sun light bias at low chopper frequency is suggested to more accurately determine the external quantum efficiency. 相似文献
14.
An improved solar cell circuit model for organic solar cells 总被引:1,自引:0,他引:1
The validity of conventional circuit model for interpreting results obtained using organic solar cells is examined. It is shown that the central assumption in the model that photo-generated current remains constant from short-circuit to open-circuit condition may not hold for organic cells. An improved model based on the photovoltaic response of organic solar cells is proposed and a method of extracting the parameters of the model is presented. 相似文献
15.
Mikkel Jørgensen Kion Norrman Frederik C. Krebs 《Solar Energy Materials & Solar Cells》2008,92(7):686-714
Polymer and organic solar cells degrade during illumination and in the dark. This is in contrast to photovoltaics based on inorganic semiconductors such as silicon. Long operational lifetimes of solar cell devices are required in real-life application and the understanding and alleviation of the degradation phenomena are a prerequisite for successful application of this new and promising technology. In this review, the current understanding of stability/degradation in organic and polymer solar cell devices is presented and the methods for studying and elucidating degradation are discussed. Methods for enhancing the stability through the choice of better active materials, encapsulation, application of getter materials and UV-filters are also discussed. 相似文献
16.
The photovoltaic behavior in a perylene/phthalocyanine hetero-p/n-junction solar cell was investigated using intensity-dependent I/V-characteristics and short circuit photocurrent spectroscopy. It is concluded that the charge carrier generation occurs only in a very thin active region at the contact. By optimizing the light trapping, a maximum solar AM 1.5 efficiency of about 2% can be obtained. A further increase requires better material properties or new cell structures. 相似文献
17.
Mohammad Tavakkoli Rasul Ajeian Moosa Nakhaee BadrabadiSaeed Saleh Ardestani Sayid Mohammad Hasan FeizKomeil Elahi Nasab 《Solar Energy Materials & Solar Cells》2011,95(7):1964-1969
In this paper, the stability of small-molecule organic solar cells based on copper phthalocyanine (CuPc) and fullerene (C60) is investigated. The use of silver instead of aluminum as the metal electrode in these solar cells, with smaller grain size and grain boundaries as well as with more uniform grain size distribution in the film, results in significant improvement in the lifetime of the devices. The substantial role of silver in the protection of the cells against permeation of oxygen and/or water molecules into the organic thin films is confirmed. Substitution of a thin buffer layer (70 Å) of bathophenanthroline (Bphen) for bathocuproine (BCP), sandwiched between C60 and the cathode, makes considerable progress in the lifetime of the device. 相似文献
18.
Monica Lira-Cantu Amine ChafiqJeremy Faissat Irene Gonzalez-VallsYouhai Yu 《Solar Energy Materials & Solar Cells》2011,95(5):1362-1374
In this work, we study the effect of the transparent conducting oxide (TCO) and the polymer applied (MEH-PPV or P3HT) on the photovoltaic properties of TCO/TiO2/polymer/Ag bi-layer solar cells. The solar cells were analyzed under inert atmosphere conditions resembling an encapsulated or sealed device. We demonstrate that the substrate applied, ITO or FTO, modifies the crystalline structure of the TiO2: on an ITO substrate, TiO2 is present in its anatase phase, on an FTO, the rutile phase predominates. Devices fabricated on an FTO, where the rutile phase is present, show better stability under inert atmospheres than devices fabricated on an ITO, anatase phase. With respect to the polymer, devices based on MEH-PPV show higher Voc (as high as 1 V), while the application of P3HT results in lower Voc, but higher Jsc and longer device stability. These observations have been associated to (a), the crystalline structure of TiO2 and (b) to the form the polymer is bonded to the TiO2 surface. In-situ IPCE analyses of P3HT-based solar cells show a red shift on the peak corresponding to TiO2, which is not present on the MEH-PPV-based solar cells. The latter suggest that P3HT can be linked to the TiO2 though the S-end atom, which results in devices with lower Voc. All these observations are also valid for devices, where the bare TiO2 is replaced by an Nb-TiO2. The application of an Nb-TiO2 with rutile structure in these polymer/oxide solar cells is the reason for their higher stability under inert atmospheres. We conclude that the application of TiO2 in its rutile phase is beneficial for long-term stability devices. Moreover there is an interplay between low Voc and Jsc in devices applying P3HT, since power conversion efficiency can be partially canceled by their lower Voc in comparison with MEH-PPV. These findings are important for polymer/oxide solar cells, but also for organic solar cells, where a layer of semiconductor oxides are in direct contact with a polymer, like in an inverted or tandem organic solar cells. 相似文献
19.
Jiguang LiSunhee Kim Sean EdingtonJoseph Nedy Shinuk Cho Kwanghee Lee Alan J Heeger Mool C. Gupta John T. Yates Jr 《Solar Energy Materials & Solar Cells》2011,95(4):1123-1130
We describe a study of the stabilization behavior of P3HT/PCBM organic solar cells under air and UV irradiation using a 20 nm thin TiOx protection layer made by partial hydrolysis of a Ti-alkoxide and spin coating in air. Data on the degradation of solar cell performance under air and under UV exposure are presented indicating that significant improvements are observed with TiOx layer protection. The protection mechanism has been investigated by transmission IR and UV spectroscopy and by ESR spectroscopy. The results of this study suggest how sol-gel derived TiOx films containing organic functionalities serve as effective passivation films for protection from oxygen when excited by photons, where the photooxidation of the bound organic moieties causes oxygen gas scavenging. 相似文献
20.
Alondra Matus‐Arrambide Ricardo Antonio Mendoza‐Jimnez Francisco de Moure‐Flores Sandra Andrea Mayn‐Hernndez Ma. Luz Olvera‐Amador Ma. Concepcin Arenas‐Arrocena Jos Santos Cruz 《国际能源研究杂志》2019,43(8):3723-3731
In this work, the pyrite crystalline phase of iron disulfide nanoparticles (FeS2) about 20 to 30 nm was obtained by a two‐pot thermal method at 220°C. Subsequently, different concentrations of these nanoparticles were used as a doping agent for the conjugated poly‐3‐hexylthiophene (P3HT). The electrical resistivity of P3HT was decreased almost three orders of magnitude while adding FeS2 nanoparticles as doping, and dichlorobenzene solvent was a determinant factor for the dispersion of polymer with nanoparticles. Doped‐P3HT dichlorobenzene solution was spin coated onto the FTO/TiO2 substrate to fabricate the FTO/TiO2/P3HT:FeS2/C‐Au hybrid solar cells. Moreover, the power conversion efficiency (PCE) of hybrid devices was studied as a function of pyrite FeS2 nanoparticle concentration. The highest efficiency of 0.83% was obtained at 1% concentration of FeS2 nanoparticles. Hence, the results revealed that the FeS2 nanoparticles could be considered as an alternative charge carrier to develop the bulk hybrid solar cells. 相似文献