Sung, Sae Jin; Kim, Jae Ho; Gihm, Se Hoon; Park, Jisoo; Cho, Young Shik; Yang, Seung Jae; Park, Chong Rae
Revisiting the Role of Graphene Quantum Dots in Ternary Organic Solar Cells: Insights into the Nanostructure Reconstruction and Effective Förster Resonance Energy Transfer
Recent studies have introduced the graphene quantum dot (GQD) as a third material for the bulk-heterojunction polymer:fullerene solar cell (PSC) to improve light conversion efficiency. Although exciton generation/dissociation and carrier transport in the GQD-incorporated light-absorbing layer are strongly influenced by the ternary component, detailed analysis on the role of GQD…
Enhanced gas barrier property of stacking-controlled reduced graphene oxide films for encapsulation of polymer solar cells
Sung, Sae Jin; Park, Jisoo; Cho, Young Shik; Gihm, Se Hoon; Yang, Seung Jae; Park, Chong Rae
Compact stacking of building blocks is essential in order to utilize the impermeable nature of reduced graphene oxide (rGO) for encapsulating barriers in organic electronics. To obtain the desired accumulation characteristic, rGO films were fabricated via spraying process using phase-controlled graphene oxide (GO) dispersion. The rGO laminate prepared from the…
Stabilizing Silver Window Electrodes for Organic Photovoltaics Using a Mercaptosilane Monolayer
Lee, Jaemin; Walker, Marc; Varagnolo, Silvia; Huband, Steven; Hatton, Ross A.
A single layer of the bifunctional molecule 3-mercaptopropyltrimethoxysilane is shown to be remarkably effective at improving the stability of optically thin silver film electrodes toward spontaneous morphological change and oxidation by airborne sulfur. Inclusion of this layer in the novel transparent electrode WO3(30 nm)/silver (13 nm)/solgel ZnO (27 nm) at…
Facilitate charge transfer at donor/acceptor interface in bulk heterojunction organic photovoltaics by two-dimensional nanoflakes
Yang, Weitao; Ye, Zhixiang; Liang, Tao; Ye, Jian; Chen, Hongzheng
Recently, two-dimensional (2D) materials have been applied in organic photovoltaics (OPVs) as electrode modifier or third component in bulk due to their high charge carrier mobility, various electronic band structure, and facile fabrication via liquid phase exfoliation. Herein, solution exfoliated few layers black phosphorus (BP) and tungsten diselenide (WSe2) were…
Tuning Pore Dimensions of Mesoporous Inorganic Films by Homopolymer Swelling
Reid, Barry; Alvarez-Fernandez, Alberto; Schmidt-Hansberg, Benjamin; Guldin, Stefan
The functionality and applications of mesoporous inorganic films are closely linked to their mesopore dimensions. For material architectures derived from a block copolymer (BCP) micelle coassembly, the pore size is typically manipulated by changing the molecular weight corresponding to the pore-forming block. However, bespoke BCP synthesis is often a costly…
Ultrathin Homogenous AuNP Monolayers as Tunable Functional Substrates for Surface-Assisted Laser Desorption/Ionization of Small Biomolecules
Liu, Zhen; Zhang, Peng; Kister, Thomas; Kraus, Tobias; Volmer, Dietrich A.
A series of ultrathin, homogenous gold nanoparticle (AuNP) substrates for surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) were prepared using a simple air/water interface approach. These SALDI substrates enabled soft ionization and provided significant improvements in terms of signal intensities and reduced background levels in comparison to other AuNP morphologies for
In-Depth Study of Coating Multimodal Porosity Using Ellipsometry Porosimetry in Desorption Scanning Mode
Loizillon, Jérôme; Baumgartner, Bettina; Sinturel, Christophe; Abbarchi, Marco; Lendl, Bernhard; Grosso, David
Ellipsometry porosimetry provides full adsorption/desorption isotherms and is among the most accurate techniques to probe porosity in thin films. Here we address a novel technique based on desorption scanning for a precise assessment of the porosity features revealing the size distribution of interconnections between the various populations of pores in…
Transition Pathway between Gyroid and Cylindrical Morphology in Linear Triblock Terpolymer Thin Films
Guliyeva, Aynur; Vayer, Marylène; Warmont, Fabienne; Takano, Atsushi; Matsushita, Yushu; Sinturel, Christophe
A new transition between alternating gyroid (GA) structure and cylindrical morphology was observed in thin films for a poly(isoprene-block-styrene-block-(2-vinylpyridine)) (ISP) triblock terpolymer (I/S/P volume fraction = 0.20:0.66:0.14) exhibiting in bulk a Q214 (space group I4132) morphology. Thin films were organized using solvent vapor annealing (SVA) and characterized by atomic force
Comprehensive Investigation and Analysis of Bulk-Heterojunction Microstructure of High-Performance PCE11:PCBM Solar Cells
Zhang, Chaohong; Heumueller, Thomas; Gruber, Wolfgang; Almora, Osbel; Du, Xiaoyan; Ying, Lei; Chen, Junwu; Unruh, Tobias; Cao, Yong; Li, Ning; Brabec, Christoph J.
Worldwide research efforts have been devoted to organic photovoltaics in the hope of a large-scale commercial application in the near future. To meet the industrial production requirements, organic photovoltaics that can reach power conversion efficiency (PCE) of over 10% along with promising operational device stability are of utmost interest. In…
A top-down strategy identifying molecular phase stabilizers to overcome microstructure instabilities in organic solar cells
Zhang, Chaohong; Heumueller, Thomas; Leon, Salvador; Gruber, Wolfgang; Burlafinger, Klaus; Tang, Xiaofeng; Perea, Jose D.; Wabra, Isabell; Hirsch, Andreas; Unruh, Tobias; Li, Ning; Brabec, Christoph J.
The operational stability of organic solar cells (OSCs) is the essential barrier to commercialization. Compared to thermally-induced degradation, photo-stability of OSCs is far away from being resolved. Here, we demonstrate that the thermal- and photo-degradation of metastable bulk-heterojunction OSCs are governed by the same mechanism. Understanding the fundamental principles behind…