We demonstrate the hydrothermal synthesis of long copper nanowires based on a simple protocol. We show that the purification of the nanowires is very important and can be achieved easily by wet treatment with glacial ...We demonstrate the hydrothermal synthesis of long copper nanowires based on a simple protocol. We show that the purification of the nanowires is very important and can be achieved easily by wet treatment with glacial acetic acid. Fabrication of random networks of purified copper nanowires leads to flexible transparent electrodes with excellent optoelectronic performances （e.g., 55 Ω/sq. at 94% transparency）. The process is carried out at room temperature and no post-treatment is necessary. Hybrid materials with the conductive polymer PEDOT：PSS show similar properties （e.g., 46 Ω/sq, at 93% transparency）, with improved mechanical properties. Both electrodes were integrated in capacitive touch sensors.展开更多
近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类...近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类型的添加材料构成纳米复合材料后,额外引入的声子-界面散射能进一步降低热导率,同时有机无机材料能带不匹配引起的载流子筛选效应进一步提升塞贝克(Seebeck)系数。因此,目前大量工作证明有机无机纳米复合热电材料有潜力获得高的热电优值(Figure of merit,ZT),在微型热电制冷器件、柔性可穿戴发电设备、温度传感器等领域均具有光明的应用前景。本文聚焦聚(3,4-乙烯二氧噻吩)∶聚(苯乙烯磺酸盐)(PEDOT∶PSS)热电材料及以其为基底构成的纳米复合材料热电性能的研究工作,综述了提升PEDOT∶PSS热电性能的物理方法、化学试剂改性法等。进一步重点讨论了加入不同类型的无机填料的PEDOT∶PSS基纳米复合材料热电性质的研究进展,并揭示了其热电性能提升的内在机制。展开更多
PEDOT:PSS buffer layers have been processed with the standard annealing step used for organic solar cells device applications. The d.c. conductivity σ as a function of temperature for two heating rates under He and a...PEDOT:PSS buffer layers have been processed with the standard annealing step used for organic solar cells device applications. The d.c. conductivity σ as a function of temperature for two heating rates under He and atmospheric air was studied. Moreover, the stability of the conductivity was investigated at different temperatures and environments vs time. The main results can be summarized in the following: the increase of σ due to the thermal activation of the carriers and the improvement of the crystallinity compete with the decrease of σ resulting from the irreversible structural degradation of the polymer chains promoted by the oxygen and moisture of the atmospheric air. The heat treatment time and the temperature at which the two competing mechanisms result in a maximum of the electrical conductivity have been determined and results are discussed relevant to organic optoelectronic devices containing PEDOT: PSS buffer layers.展开更多
Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the mo...Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the most actively studied hole transport material in p-i-n structured PSCs.However,charge transport in the PEDOT:PSS is limited and inefficient because of its low conductivity with the presence of the weak ionic conductor PSS.In addition,morphology of the underlying PEDOT:PSS layer in PSCs plays a crucial role in determining the optoelectronic quality of the active perovskite absorber layer.This work is focused on realization of a non-wetting conductive surface of hole transport layer suitable for the growth of larger perovskite crystalline domains.This is accomplished by employing a facile solventengineered(ethylene glycol and methanol)approach resulting in removal of the predominant PSS in PEDOT:PSS.The consequence of acquiring larger perovskite crystalline domains was observed in the charge carrier dynamics studies,with the achievement of higher charge carrier lifetime,lower charge transport time and lower transfer impedance in the solvent-engineered PEDOT:PSS-based PSCs.Use of this solventengineered treatment for the fabrication of MAPbI3 PSCs greatly increased the device stability witnessing a power conversion efficiency of 18.18%,which corresponds to^37%improvement compared to the untreated PEDOT:PSS based devices.展开更多
In this study, organic solar cells (OSCs) with an active layer, a blend of polymer of non-fullerene (NFA) Y6 as an acceptor, and donor PBDB-T-2F as donor were simulated through the one-dimensional solar capacitance si...In this study, organic solar cells (OSCs) with an active layer, a blend of polymer of non-fullerene (NFA) Y6 as an acceptor, and donor PBDB-T-2F as donor were simulated through the one-dimensional solar capacitance simulator (SCAPS-1D) software to examine the performance of this type of organic polymer thin-film solar cell by varying the thickness of the active layer. PFN-Br interfacial layer entrenched in OPV devices gives overall enhanced open-circuit voltage, short-circuit current density and fill factor thus improving device performance. PEDOT: PSS is an electro-conductive polymer solution that has been extensively utilized in solar cell devices as a hole transport layer (HTL) due to its strong hole affinity, good thermal and mechanical stability, high work function, and high transparency in the visible range. The structure of the organic solar cell is ITO/PEDOT: PSS/BTP-4F: PBDB-T-2F/PFN-Br/Ag. Firstly, the active layer thickness was optimized to 100 nm;after that, the active-layer thickness was varied up to 900 nm. The results of these simulations demonstrated that the active layer thickness improves efficiency significantly up to 500 nm, then it decreased with increasing the thickness of the active layer from 600 nm, also notice that the short circuit current and the fill factor decrease with increasing the active layer from 600 nm, while the open voltage circuit increased with increasing the thickness of the active layer. The optimum thickness is 500 nm.展开更多
文摘We demonstrate the hydrothermal synthesis of long copper nanowires based on a simple protocol. We show that the purification of the nanowires is very important and can be achieved easily by wet treatment with glacial acetic acid. Fabrication of random networks of purified copper nanowires leads to flexible transparent electrodes with excellent optoelectronic performances （e.g., 55 Ω/sq. at 94% transparency）. The process is carried out at room temperature and no post-treatment is necessary. Hybrid materials with the conductive polymer PEDOT：PSS show similar properties （e.g., 46 Ω/sq, at 93% transparency）, with improved mechanical properties. Both electrodes were integrated in capacitive touch sensors.
文摘近年来,随着能源危机的加剧,可以将热能与电能进行直接转换的热电材料得到了广泛的关注。在众多热电材料体系中,有机无机纳米复合热电材料具有独特优势。相比于无机材料,有机材料成本低、质量轻、机械柔韧性好、热导率较低。添加不同类型的添加材料构成纳米复合材料后,额外引入的声子-界面散射能进一步降低热导率,同时有机无机材料能带不匹配引起的载流子筛选效应进一步提升塞贝克(Seebeck)系数。因此,目前大量工作证明有机无机纳米复合热电材料有潜力获得高的热电优值(Figure of merit,ZT),在微型热电制冷器件、柔性可穿戴发电设备、温度传感器等领域均具有光明的应用前景。本文聚焦聚(3,4-乙烯二氧噻吩)∶聚(苯乙烯磺酸盐)(PEDOT∶PSS)热电材料及以其为基底构成的纳米复合材料热电性能的研究工作,综述了提升PEDOT∶PSS热电性能的物理方法、化学试剂改性法等。进一步重点讨论了加入不同类型的无机填料的PEDOT∶PSS基纳米复合材料热电性质的研究进展,并揭示了其热电性能提升的内在机制。
文摘PEDOT:PSS buffer layers have been processed with the standard annealing step used for organic solar cells device applications. The d.c. conductivity σ as a function of temperature for two heating rates under He and atmospheric air was studied. Moreover, the stability of the conductivity was investigated at different temperatures and environments vs time. The main results can be summarized in the following: the increase of σ due to the thermal activation of the carriers and the improvement of the crystallinity compete with the decrease of σ resulting from the irreversible structural degradation of the polymer chains promoted by the oxygen and moisture of the atmospheric air. The heat treatment time and the temperature at which the two competing mechanisms result in a maximum of the electrical conductivity have been determined and results are discussed relevant to organic optoelectronic devices containing PEDOT: PSS buffer layers.
基金supported by NSF MRI (1428992)NASA EPSCoR (NNX15AM83A)+3 种基金U.S.–Egypt Science and Technology (S&T) Joint FundSDBoR R&D ProgramEDA University Center Program (ED18DEN3030025)supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC0206CH11357.
文摘Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the most actively studied hole transport material in p-i-n structured PSCs.However,charge transport in the PEDOT:PSS is limited and inefficient because of its low conductivity with the presence of the weak ionic conductor PSS.In addition,morphology of the underlying PEDOT:PSS layer in PSCs plays a crucial role in determining the optoelectronic quality of the active perovskite absorber layer.This work is focused on realization of a non-wetting conductive surface of hole transport layer suitable for the growth of larger perovskite crystalline domains.This is accomplished by employing a facile solventengineered(ethylene glycol and methanol)approach resulting in removal of the predominant PSS in PEDOT:PSS.The consequence of acquiring larger perovskite crystalline domains was observed in the charge carrier dynamics studies,with the achievement of higher charge carrier lifetime,lower charge transport time and lower transfer impedance in the solvent-engineered PEDOT:PSS-based PSCs.Use of this solventengineered treatment for the fabrication of MAPbI3 PSCs greatly increased the device stability witnessing a power conversion efficiency of 18.18%,which corresponds to^37%improvement compared to the untreated PEDOT:PSS based devices.
文摘In this study, organic solar cells (OSCs) with an active layer, a blend of polymer of non-fullerene (NFA) Y6 as an acceptor, and donor PBDB-T-2F as donor were simulated through the one-dimensional solar capacitance simulator (SCAPS-1D) software to examine the performance of this type of organic polymer thin-film solar cell by varying the thickness of the active layer. PFN-Br interfacial layer entrenched in OPV devices gives overall enhanced open-circuit voltage, short-circuit current density and fill factor thus improving device performance. PEDOT: PSS is an electro-conductive polymer solution that has been extensively utilized in solar cell devices as a hole transport layer (HTL) due to its strong hole affinity, good thermal and mechanical stability, high work function, and high transparency in the visible range. The structure of the organic solar cell is ITO/PEDOT: PSS/BTP-4F: PBDB-T-2F/PFN-Br/Ag. Firstly, the active layer thickness was optimized to 100 nm;after that, the active-layer thickness was varied up to 900 nm. The results of these simulations demonstrated that the active layer thickness improves efficiency significantly up to 500 nm, then it decreased with increasing the thickness of the active layer from 600 nm, also notice that the short circuit current and the fill factor decrease with increasing the active layer from 600 nm, while the open voltage circuit increased with increasing the thickness of the active layer. The optimum thickness is 500 nm.
