The Experts below are selected from a list of 16131 Experts worldwide ranked by ideXlab platform
Xiong Gong - One of the best experts on this subject based on the ideXlab platform.
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perovskite Hybrid Solar Cells with a fullerene derivative electron extraction layer
Journal of Materials Chemistry C, 2017Co-Authors: Xiang Yao, Xiong Gong, Kai Wang, Tianyu Meng, Fei Huang, Yong CaoAbstract:Perovskite Hybrid Solar Cells (pero-HSCs) have attracted great attention in the past 7 years. Boosting the efficiency of pero-HSCs is still one ongoing direction. In this study, we report efficient pero-HSCs with [6,6]-phenyl C61-butyric acid methyl ester (PC61BM) as an electron extraction layer (EEL), where the PC61BM EEL is processed from chlorobenzene mixed with pyridine solution (PC61BM-Py EEL) rather than from pure chlorobenzene solution (PC61BM EEL). It is found that the PC61BM-Py EEL exhibits dramatically enhanced electrical conductivity and has a smoother and denser thin film, as compared with that of the PC61BM EEL. Moreover, transient photovoltage and transient photocurrent measurements demonstrate that a long charge carrier lifetime and a short charge extraction time are observed for the pero-HSCs incorporated with the PC61BM-Py EEL, as compared with that with the PC61BM EEL, indicating that the charge carrier recombination is significantly reduced. As a result, more than 21.6% enhanced efficiency is observed for the pero-HSCs incorporated with the PC61BM-Py EEL. Our finding provides a simple but an effective way to significantly boost the efficiency of pero-HSCs.
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high performance perovskite Hybrid Solar Cells with e beam processed tiox electron extraction layer
ACS Applied Materials & Interfaces, 2016Co-Authors: Tianyu Meng, Chang Liu, Kai Wang, Yu Zhu, Abdullah M Alenizi, Ahmed A Elzatahry, Xiong GongAbstract:Perovskite Hybrid Solar Cells (pero-HSCs) have drawn great attention in the last 5 years. The efficiencies of pero-HSCs have been boosted from 3.8% to over 20%. However, one of the bottlenecks for commercialization of pero-HSCs is to make a high electrical conductive TiOx electron extraction layer (EEL). In this study, we report high performance pero-HSCs with TiOx EEL, where the TiOx EEL is fabricated by electron beam (e-beam) evaporation, which has been proved to be a well-developed manufacturing process. The resistance of the e-beam evaporated TiOx EEL is smaller than that of sol–gel processed TiOx EEL. Moreover, the dark current densities and interfacial charge carrier recombination of pero-HSCs incorporated with e-beam processed TiOx EEL is also smaller than that of pero-HSCs incorporated with sol–gel processed TiOx EEL. All these result in efficient pero-HSCs with high reproducibility. These results demonstrate that our method provides a simple and facile way to approach high performance pero-HSCs.
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efficient perovskite Hybrid Solar Cells through a homogeneous high quality organolead iodide layer
Small, 2015Co-Authors: Kai Wang, Haoli Zhang, Chang Liu, Xiong GongAbstract:Fabricating homogeneous and high-quality perovskite thin films via low-temperature solution processing is a challenge to realizing high-efficiency perovskite Hybrid Solar Cells (pero-HSCs). Here, an approach is reported to realize smooth surface morphology of methylammonium lead iodide (CH3NH3PbI3) perovskite thin films via using strong-polar ethanol solution rather than less-polar isopropanol solution, which was previously used as the solvent for preparing perovskite thin films. In comparison with the pero-HSCs processed from isopropanol solution, more than 40% enhanced efficiency is observed from pero-HSCs processed from ethanol solution. The enhanced efficiency is attributed to a homogeneous high-quality perovskite thin film with dramatically low root-mean-square roughness and completely conversion of lead (II) iodide (PbI2) to CH3NH3PbI3. The findings provide a simple way to realize high-efficiency high-reproducible pero-HSCs.
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efficient solution processed bulk heterojunction perovskite Hybrid Solar Cells
Advanced Energy Materials, 2015Co-Authors: Chang Liu, Kai Wang, Tianyu Meng, Xiong GongAbstract:Efficient conventional bulk heterojunction (BHJ) perovskite Hybrid Solar Cells (pero-HSCs) solution-processed from a composite of CH3NH3PbI3 mixed with PC61BM ([6,6]-phenyl-C61-butyric acid methyl ester), where CH3NH3PbI3 acts as the electron donor and PC61BM acts as the electron acceptor, are reported for the first time. The efficiency of 12.78% is twofold enhancement in comparison with the conventional planar heterojunction pero-HSCs (6.90%) fabricated by pristine CH3NH3PbI3. The BHJ pero-HSCs are further optimized by using PC61BM/TiO2 bi-electron-extraction-layer (EEL), which are both solution-processed and then followed with low-temperature thermal annealing. Due to higher electrical conductivity of PC61BM over that of TiO2, an efficiency of 14.98%, the highest reported efficiency for the pero-HSCs without incorporating high-temperature-processed mesoporous TiO2 and Al2O3 as the EEL and insulating scaffold, is observed from PC61BM modified BHJ pero-HSCs. Thus, the findings provide a simple way to approach high efficiency low-cost pero-HSCs.
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self powered electronics by integration of flexible solid state graphene based supercapacitors with high performance perovskite Hybrid Solar Cells
Advanced Functional Materials, 2015Co-Authors: Huckleberry C Liu, Peng Liu, Haoli Zhang, Xiong GongAbstract:To develop high-capacitance flexible solid-state supercapacitors and explore its application in self-powered electronics is one of ongoing research topics. In this study, self-stacked solvated graphene (SSG) films are reported that have been prepared by a facile vacuum filtration method as the free-standing electrode for flexible solid-state supercapacitors. The highly hydrated SSG films have low mass loading, high flexibility, and high electrical conductivity. The flexible solid-state supercapacitors based on SSG films exhibit excellent capacitive characteristics with a high gravimetric specific capacitance of 245 F g−1 and good cycling stability of 10 000 cycles. Furthermore, the flexible solid-state supercapacitors are integrated with high performance perovskite Hybrid Solar Cells (pero-HSCs) to build self-powered electronics. It is found that the solid-state supercapacitors can be charged by pero-HSCs and discharged from 0.75 V. These results demonstrate that the self-powered electronics by integration of the flexible solid-state supercapacitors with pero-HSCs have great potential applications in storage of Solar energy and in flexible electronics, such as portable and wearable personal devices.
Baoquan Sun - One of the best experts on this subject based on the ideXlab platform.
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solution processed highly conductive pedot pss agnw go transparent film for efficient organic si Hybrid Solar Cells
ACS Applied Materials & Interfaces, 2015Co-Authors: Tao Song, Shuit-tong Lee, Wei Cui, Yuqiang Liu, Baoquan SunAbstract:Hybrid Solar Cells based on n-Si/poly(3,4-ethylenedioxythiophene):poly(styrene- sulfonate) (PEDOT:PSS) heterojunction promise to be a low cost photovoltaic technology by using simple device structure and easy fabrication process. However, due to the low conductivity of PEDOT:PSS, a metal grid deposited by vacuum evaporation method is still required to enhance the charge collection efficiency, which complicates the device fabrication process. Here, a solution-processed graphene oxide (GO)-welded silver nanowires (AgNWs) transparent conductive electrode (TCE) was employed to replace the vacuum deposited metal grid. A unique “sandwich” structure was developed by embedding an AgNW network between PEDOT:PSS and GO with a figure-of-merit of 8.6 × 10–3 Ω–1, which was even higher than that of sputtered indium tin oxide electrode (6.6 × 10–3 Ω–1). A champion power conversion efficiency of 13.3% was achieved, because of the decreased series resistance of the TCEs as well as the enhanced built-in potential (Vbi) in ...
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two dimensional cos nanosheets used for high performance organic inorganic Hybrid Solar Cells
Journal of Physical Chemistry C, 2014Co-Authors: Xiao Fang, Tao Song, Ruiyuan Liu, Baoquan SunAbstract:Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) is one of the most popular hole-transporting materials in organic–Si Hybrid Solar Cells. However, the inferior sheet resistance and the low work function of the PEDOT:PSS layer hinder the power conversion efficiency (PCE) of the devices. Here, two-dimensional cobalt sulfide (CoS) nanosheets with a low sheet resistance and higher work function are blended into the PEDOT:PSS films in order to enhance the device performance. By tuning the morphology and concentration of CoS nanosheets in the PEDOT:PSS films, a lower recombination rate at the organic–inorganic interfaces and improved hole-transporting ability can be achieved simultaneously, yielding a PCE of 11.2% under simulated air mass 1.5 Solar irradiation at 100 mW cm–2. The scanning Kelvin probe microscopy, the ultraviolet photoelectron spectroscopy, four-probe sheet resistance measurement, and the transient electrical output characterization were used to study the origin of performance...
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Effect of Series and Shunt Resistance on Organic-Inorganic Hybrid Solar Cells Performance
Electrochimica Acta, 2014Co-Authors: Jie Zhang, Shuit-tong Lee, Baoquan SunAbstract:Abstract Organic-inorganic Solar Cells based on n-type silicon (100) and poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) exhibit great photo-electron conversion abilities while utilizing a simple fabrication process. In organic-inorganic Hybrid Solar Cells, the device can be described by an equivalent circuit for a duodiode model. In this model, it is found that the fluctuation of the series and shunt resistance can dramatically influence the output characteristics. In this letter, the series and shunt resistance is tuned to observe its effect on the device performance. It is found that with suitable substrate scales and physical tailoring methods, the shunt and series resistances can be adjusted to eliminate the unfavorable charge trapping phenomenon. Meanwhile, the fill factor is also enhanced notably up to 0.74, which yields a power conversion efficiency of 12.1%. These results indicate that the junction quality plays a key role in the performance of the Hybrid organic-inorganic Solar cell.
Henry J Snaith - One of the best experts on this subject based on the ideXlab platform.
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protic ionic liquids as p dopant for organic hole transporting materials and their application in high efficiency Hybrid Solar Cells
Journal of the American Chemical Society, 2013Co-Authors: Antonio Abate, Derek J Hollman, Joel Teuscher, S Pathak, Roberto Avolio, Gerardino Derrico, Giuseppe Vitiello, Simona Fantacci, Henry J SnaithAbstract:Chemical doping is a powerful method to improve the charge transport and to control the conductivity in organic semiconductors (OSs) for a wide range of electronic devices. We demonstrate protic ionic liquids (PILs) as effective p-dopant in both polymeric and small molecule OSs. In particular, we show that PILs promote single electron oxidation, which increases the hole concentration in the semiconducting film. The illustrated PIL-doping mechanism is compatible with materials processed by solution and is stable in air. We report the use of PIL-doping in Hybrid Solar Cells based on triarylamine hole transporting materials, such as 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene (spiro-OMeTAD). We show improved power conversion efficiency by replacing lithium salts, typical p-dopants for spiro-OMeTAD, with PILs. We use photovoltage–photocurrent decay and photoinduced absorption spectroscopy to establish that significantly improved device performance is mainly due to reduced charge trans...
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high performance perovskite polymer Hybrid Solar Cells via electronic coupling with fullerene monolayers
Nano Letters, 2013Co-Authors: Agnese Abrusci, Pablo Docampo, Samuel D Stranks, Henry J SnaithAbstract:A plethora of solution-processed materials have been developed for Solar cell applications. Hybrid Solar Cells based on light absorbing semiconducting polymers infiltrated into mesoporous TiO2 are an interesting concept, but generating charge at the polymer–metal oxide heterojunction is challenging. Metal–organic perovskite absorbers have recently shown remarkable efficiencies but currently lack the range of color tunability of organics. Here, we have combined a fullerene self-assembled monolayer (C60SAM) functionalized mesoporous titania, a perovskite absorber (CH3NH3PbI3–xClx), and a light absorbing polymer hole-conductor, P3HT, to realize a 6.7% efficient Hybrid Solar cell. We find that photoexcitations in both the perovskite and the polymer undergo very efficient electron transfer to the C60SAM. The C60SAM acts as an electron acceptor but inhibits further electron transfer into the TiO2 mesostructure due to energy level misalignment and poor electronic coupling. Thermalized electrons from the C60SAM a...
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facile infiltration of semiconducting polymer into mesoporous electrodes for Hybrid Solar Cells
Energy and Environmental Science, 2011Co-Authors: Agnese Abrusci, Ikang Ding, Mohammed Alhashimi, Tamar Segalperetz, Michael D Mcgehee, Martin Heeney, Gitti L Frey, Henry J SnaithAbstract:Hybrid composites of semiconducting polymers and metal oxides are promising combinations for Solar Cells. However, forming a well-controlled nanostructure with bicontinuous interpenetrating networks throughout the photoactive film is difficult to achieve. Pre-structured “mesoporous” metal oxide electrodes can act as a well-defined template for latter polymer infiltration. However, the long range infiltration of polymer chains into contorted porous channels has appeared to elude the scientific community, limiting the advancement of this technology. Here we present a structural and electronic characterisation of poly(3-hexylthiophene) (P3HT) infiltrated into mesoporous dye-sensitized TiO2. Through a combination of techniques we achieve uniform pore filling of P3HT up to depths of over 4 μm, but the volumetric fraction of the pores filled with polymer is less than 24%. Despite this low pore-filling, exceptionally efficient charge collection is demonstrated, illustrating that pore filling is not the critical issue for mesoporous Hybrid Solar Cells.
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lead sulphide quantum dot sensitization of tin oxide based Hybrid Solar Cells
Solar Energy, 2011Co-Authors: Henry J Snaith, Alexandros Stavrinadis, Pablo Docampo, Andrew A R WattAbstract:We have fabricated infrared active Hybrid Solar Cells composed of mesoporous SnO2 sensitized with PbS nanoparticles and infiltrated with organic hole-transporters, 2,2′,7,7′-tetrakis(N,N-di-p-methoxypheny-amine)-9,9′-spirobifluorene(spiro-OMeTAD) or poly(3-hexylthiophene). We observe photo-action to 1100 nm, peak quantum-efficiency over 20%, open-circuit voltages up to 0.5 V and power conversion efficiencies of over 0.5% under simulated sun light. As compared to Solar Cells composed of mesoporous TiO2 sensitized with the same PbS nanoparticles, the SnO2 based devices generate 4 times the photocurrent density under simulated sun light.
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sno2 based dye sensitized Hybrid Solar Cells exhibiting near unity absorbed photon to electron conversion efficiency
Nano Letters, 2010Co-Authors: Henry J Snaith, Caterina DucatiAbstract:Improving the Solar light harvesting and photon-to-electron conversion efficiency for Hybrid, organic−inorganic photovoltaics are critical challenges. Titania based solid-state Hybrid Solar Cells are moderately efficient at converting visible photons to electrons, but major electrical losses still remain. A material based paradigm shift is required to dramatically enhance the performance of these devices. Here, we present an investigation into solid-state dye-sensitized Solar Cells (SDSCs) incorporating a molecular hole-transporter and mesoporous tin oxide electrodes, in place of titania usually employed. We investigate the influence of treating the surface of the SnO2 with different oxides and find that MgO “passivated” SnO2 electrodes demonstrate an unprecedented absorbed photon-to-electron conversion efficiency of near unity across a broad spectral range. A dual surface treatment of TiO2 followed by MgO enables tuning of the Solar cell photovoltage, fill factor, and efficiency with visible light absorb...
Michael Kruger - One of the best experts on this subject based on the ideXlab platform.
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efficiency enhancement for bulk heterojunction Hybrid Solar Cells based on acid treated cdse quantum dots and low bandgap polymer pcpdtbt
Solar Energy Materials and Solar Cells, 2011Co-Authors: Yunfei Zhou, Clemens Veit, Birger Zimmermann, Sybille Allard, Ines Dumsch, Ullrich Scherf, Frank Rauscher, Phenwisa Niyamakom, Seyfullah Yilmaz, Michael KrugerAbstract:Abstract We report on the efficiency enhancement for bulk-heterojunction Hybrid Solar Cells based on hexanoic acid treated trioctylphosphine/oleic acid-capped CdSe quantum dots (QDs) and low bandgap polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4 H -cyclopenta[2,1- b ;3,4- b ′]-dithiophene)- alt -4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) compared to devices based on poly(3-hexylthiophene) (P3HT). Photovoltaic devices with optimized polymer:QD weight ratio, photoactive film thickness, thermal annealing treatment, and cathode materials exhibited a power conversion efficiency of 2.7% after spectral mismatch correction, which is the highest reported value for spherical CdSe QD based photovoltaic devices. The efficiency enhancement is attributed to the surface treatment of the QDs together with the use of the low bandgap polymer PCPDTBT leading to an increased short-circuit current density due to additional light absorption between 650 and 850 nm. Our results suggest that the hexanoic acid treatment is generally applicable to various ligand-capped CdSe and confirm that low bandgap polymers with adequate HOMO and LUMO levels are promising to be incorporated into Hybrid Solar Cells for further device performance improvement.
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improved efficiency of Hybrid Solar Cells based on non ligand exchanged cdse quantum dots and poly 3 hexylthiophene
Applied Physics Letters, 2010Co-Authors: Yunfei Zhou, Frank S Riehle, Ying Yuan, Hansfrieder Schleiermacher, Michael Niggemann, Gerald Urban, Michael KrugerAbstract:We report on bulk-heterojunction Hybrid Solar Cells based on blends of non-ligand-exchanged CdSe quantum dots (QDs) and the conjugated polymer poly(3-hexylthiophene) with improved power conversion efficiencies of about 2% under AM1.5G illumination after spectral mismatch correction. This is the highest reported value for a spherical CdSe QD based photovoltaic device. After synthesis, the CdSe QDs are treated by a simple and fast acid-assisted washing procedure, which has been identified as a crucial factor in enhancing the device performance. A simple model of a reduced ligand sphere is proposed explaining the power conversion efficiency improvement.
Xixi Wang - One of the best experts on this subject based on the ideXlab platform.
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heterojunction Hybrid Solar Cells by formation of conformal contacts between pedot pss and periodic silicon nanopyramid arrays
Small, 2018Co-Authors: Zhenhai Yang, Tianbao Yu, Xixi Wang, Jian He, Xi Yang, Jichun YeAbstract:A poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/textured Si heterojunction Solar cell with a fully conformal contact is achieved by employing a periodic upright nanopyramid array and a silane chemical‐incorporated PEDOT:PSS solution. The resulting PEDOT:PSS/Si Hybrid Solar Cells textured with arrays show a promising power conversion efficiency of 13.8%, significantly higher than 12.1% of the Cells based on the‐state‐of‐the‐art surface texture with random pyramids.
