Ultrathin organic solar cells with graphene doped by ferroelectric polarization

Advances in Stretchable Organic Photovoltaics: Flexible Transparent Electrodes and Deformable Active Layer Design

Stretchable organic photovoltaics (OPVs) have attracted significant attention as promising power sources for wearable electronic systems owing to their superior robustness under repetitive tensile strains and their good compatibility. However, reconciling a high power-conversion efficiency and a reasonable flexibility is a tremendous challenge. In addition, the development of stretchable OPVs must be accelerated to satisfy the increasing requirements of niche markets for mechanical robustness. Stretchable OPV devices can be classified as either structurally or intrinsically stretchable. This work reviews recent advances in stretchable OPVs, including the design of mechanically robust transparent electrodes, photovoltaic materials, and devices. Initially, an overview of the characteristics and recent research progress in the areas of structurally and intrinsically stretchable OPVs is provided. Subsequently, research into flexible and stretchable transparent electrodes that directly affect the performances of stretchable OPVs is summarized and analyzed. Overall, this review aims to provide an in-depth understanding of the intrinsic properties of highly efficient and deformable active materials, while also emphasizing advanced strategies for simultaneously improving the photovoltaic performance and mechanical flexibility of the active layer, including material design, multi-component settings, and structural optimization.

Nanostructured Conductive Polypyrrole for Antibacterial Components in Flexible Wearable Devices

The power generated by flexible wearable devices (FWDs) is normally insufficient to eradicate bacteria, and many conventional antibacterial strategies are also not suitable for flexible and wearable applications because of the strict mechanical and electrical requirements. Here, polypyrrole (PPy), a conductive polymer with a high mass density, is used to form a nanostructured surface on FWDs for antibacterial purposes. The conductive films with PPy nanorods (PNRs) are found to sterilize 98.2 ± 1.6% of Staphylococcus aureus and 99.6 ± 0.2% of Escherichia coli upon mild electrification (1 V). Bacteria killing stems from membrane stress produced by the PNRs and membrane depolarization caused by electrical neutralization. Additionally, the PNR films exhibit excellent biosafety and electrical stability. The results represent pioneering work in fabricating antibacterial components for FWDs by comprehensively taking into consideration the required conductivity, mechanical properties, and biosafety.

BTO-Coupled CIGS Solar Cells with High Performances

In order to improve the power conversion efficiency (PCE) of Cu(In,Ga)Se₂ (CIGS) solar cells, a BaTiO₃ (BTO) layer was inserted into the Cu(In,Ga)Se₂. The performances of the BTO-coupled CIGS solar cells with structures of Mo/CIGS/CdS/i-ZnO/AZO, Mo/BTO/CIGS/CdS/i-ZnO/AZO, Mo/CIGS/BTO/CdS/i-ZnO/AZO, Mo/CIGS/CdS/BTO/i-ZnO/AZO, Mo/CIGS/BTO/i-ZnO/AZO, Mo/CIGS/CdS/BTO/AZO, and Mo/ CIGS/CdS(5 nm)/BTO(5 nm)/i-ZnO/AZO were systematically studied via the SCAPS-1D software. It was found that the power conversion efficiency (PCE) of a BTO-coupled CIGS solar cell with a device configuration of Mo/CIGS/CdS/BTO/AZO was 24.53%, and its open-circuit voltage was 931.70 mV. The working mechanism for the BTO-coupled CIGS solar cells with different device structures was proposed. Our results provide a novel strategy for improving the PCE of solar cells by combining a ferroelectric material into the p-n junction materials.

Soft Ferroelectrics Enabling High-Performance Intelligent Photo Electronics

Soft ferroelectrics based on organic and organic-inorganic hybrid materials have gained much interest among researchers owing to their electrically programmable and remnant polarization. This allows for the development of numerous flexible, foldable, and stretchable nonvolatile memories, when combined with various crystal engineering approaches to optimize their performance. Soft ferroelectrics have been recently considered to have an important role in the emerging human-connected electronics that involve diverse photoelectronic elements, particularly those requiring precise programmable electric fields, such as tactile sensors, synaptic devices, displays, photodetectors, and solar cells for facile human-machine interaction, human safety, and sustainability. This paper provides a comprehensive review of the recent developments in soft ferroelectric materials with an emphasis on their ferroelectric switching principles and their potential application in human-connected intelligent electronics. Based on the origins of ferroelectric atomic and/or molecular switching, the soft ferroelectrics are categorized into seven subgroups. In this review, the efficiency of soft ferroelectrics with their distinct ferroelectric characteristics utilized in various human-connected electronic devices with programmable electric field is demonstrated. This review inspires further research to utilize the remarkable functionality of soft electronics.

Ultra-conformal skin electrodes with synergistically enhanced conductivity for long-time and low-motion artifact epidermal electrophysiology

Accurate and imperceptible monitoring of electrophysiological signals is of primary importance for wearable healthcare. Stiff and bulky pregelled electrodes are now commonly used in clinical diagnosis, causing severe discomfort to users for long-time using as well as artifact signals in motion. Here, we report a ~100 nm ultra-thin dry epidermal electrode that is able to conformably adhere to skin and accurately measure electrophysiological signals. It showed low sheet resistance (~24 Ω/sq, 4142 S/cm), high transparency, and mechano-electrical stability. The enhanced optoelectronic performance was due to the synergistic effect between graphene and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which induced a high degree of molecular ordering on PEDOT and charge transfer on graphene by strong π-π interaction. Together with ultra-thin nature, this dry epidermal electrode is able to accurately monitor electrophysiological signals such as facial skin and brain activity with low-motion artifact, enabling human-machine interfacing and long-time mental/physical health monitoring.

Novel dry electrodes with enhanced mechano-electrical stability and conformability are attractive for long-time electrophysiological signal monitoring. Here, the authors report polymer-covered CVD-grown graphene with enhanced optoelectronic performance for biopotential monitoring.

Efficiency Enhancement with the Ferroelectric Coupling Effect Using P(VDF-TrFE) in CH3NH3PbI3 Solar Cells

A novel ferroelectric coupling photovoltaic effect is reported to enhance the open-circuit voltage (V OC) and the efficiency of CH3NH3PbI3 perovskite solar cells. A theoretical analysis demonstrates that this ferroelectric coupling effect can effectively promote charge extraction as well as suppress combination loss for an increased minority carrier lifetime. In this study, a ferroelectric polymer P(VDF-TrFE) is introduced to the absorber layer in solar cells with a proper cocrystalline process. Piezoresponse force microscopy (PFM) is used to confirm that the P(VDF-TrFE):CH3NH3PbI3 mixed thin films possess ferroelectricity, while the pure CH3NH3PbI3 films have no obvious PFM response. Additionally, with the applied external bias voltages on the ferroelectric films, the devices begin to show tunable photovoltaic performance, as expected for the polarization in the poling process. Furthermore, it is shown that through the ferroelectric coupled effect, the efficiency of the CH3NH3PbI3-based perovskite photovoltaic devices is enhanced by about 30%, from 13.4% to 17.3%. And the open-circuit voltages (V OC) reach 1.17 from 1.08 V, which is reported to be among the highest V OCs for CH3NH3PbI3-based devices. It should be noted in particular that the thickness of the layer is less than 160 nm, which can be regarded as semi-transparent.

A Double Support Layer for Facile Clean Transfer of Two-Dimensional Materials for High-Performance Electronic and Optoelectronic Devices

Clean transfer of two-dimensional (2D) materials grown by chemical vapor deposition is critical for their application in electronics and optoelectronics. Although rosin can be used as a support layer for the clean transfer of graphene grown on Cu, it has not been usable for the transfer of 2D materials grown on noble metals or for large-area transfer. Here, we report a poly(methyl methacrylate) (PMMA)/rosin double support layer that enables facile ultraclean transfer of large-area 2D materials grown on different metals. The bottom rosin layer ensures clean transfer, whereas the top PMMA layer not only screens the rosin from the transfer conditions but also improves the strength of the transfer layer to make the transfer easier and more robust. We demonstrate the transfer of monolayer WSe₂ and WS₂ single crystals grown on Au as well as large-area graphene films grown on Cu. As a result of the clean surface, the transferred WSe₂ retains the intrinsic optical properties of the as-grown sample. Moreover, it does not require annealing to form good ohmic contacts with metal electrodes, enabling high-performance field effect transistors with mobility and ON/OFF ratio ∼10 times higher than those made by PMMA-transferred WSe₂. The ultraclean graphene film is found to be a good anode for flexible organic photovoltaic cells with a high power conversion efficiency of ∼6.4% achieved.

The Role of Graphene and Other 2D Materials in Solar Photovoltaics

2D materials have attracted considerable attention due to their exciting optical and electronic properties, and demonstrate immense potential for next-generation solar cells and other optoelectronic devices. With the scaling trends in photovoltaics moving toward thinner active materials, the atomically thin bodies and high flexibility of 2D materials make them the obvious choice for integration with future-generation photovoltaic technology. Not only can graphene, with its high transparency and conductivity, be used as the electrodes in solar cells, but also its ambipolar electrical transport enables it to serve as both the anode and the cathode. 2D materials beyond graphene, such as transition-metal dichalcogenides, are direct-bandgap semiconductors at the monolayer level, and they can be used as the active layer in ultrathin flexible solar cells. However, since no 2D material has been featured in the roadmap of standard photovoltaic technologies, a proper synergy is still lacking between the recently growing 2D community and the conventional solar community. A comprehensive review on the current state-of-the-art of 2D-materials-based solar photovoltaics is presented here so that the recent advances of 2D materials for solar cells can be employed for formulating the future roadmap of various photovoltaic technologies.

Extremely stable graphene electrodes doped with macromolecular acid

Although conventional p-type doping using small molecules on graphene decreases its sheet resistance (R_sh), it increases after exposure to ambient conditions, and this problem has been considered as the biggest impediment to practical application of graphene electrodes. Here, we report an extremely stable graphene electrode doped with macromolecular acid (perfluorinated polymeric sulfonic acid (PFSA)) as a p-type dopant. The PFSA doping on graphene provides not only ultra-high ambient stability for a very long time (> 64 days) but also high chemical/thermal stability, which have been unattainable by doping with conventional small-molecules. PFSA doping also greatly increases the surface potential (~0.8 eV) of graphene, and reduces its R_sh by ~56%, which is very important for practical applications. High-efficiency phosphorescent organic light-emitting diodes are fabricated with the PFSA-doped graphene anode (~98.5 cd A⁻¹ without out-coupling structures). This work lays a solid platform for practical application of thermally-/chemically-/air-stable graphene electrodes in various optoelectronic devices.

Chemical doping is a viable strategy to tune the electrical properties of pristine graphene, but suffers from stability issues. Here, the authors develop a macromolecular chemical doping approach that makes use of polymeric acid and provides high stability.

Development of Annealing-Free, Solution-Processable Inverted Organic Solar Cells with N-Doped Graphene Electrodes using Zinc Oxide Nanoparticles

An annealing-free process is considered as a technological advancement for the development of flexible (or wearable) organic electronic devices, which can prevent the distortion of substrates and damage to the active components of the device and simplify the overall fabrication process to increase the industrial applications. Owing to its outstanding electrical, optical, and mechanical properties, graphene is seen as a promising material that could act as a transparent conductive electrode for flexible optoelectronic devices. Owing to their high transparency and electron mobility, zinc oxide nanoparticles (ZnO-NP) are attractive and promising for their application as charge transporting materials for low-temperature processes in organic solar cells (OSCs), particularly because most charge transporting materials require annealing treatments at elevated temperatures. In this study, graphene/annealing-free ZnO-NP hybrid materials were developed for inverted OSC by successfully integrating ZnO-NP on the hydrophobic surface of graphene, thus aiming to enhance the applicability of graphene as a transparent electrode in flexible OSC systems. Chemical, optical, electrical, and morphological analyses of ZnO-NPs showed that the annealing-free process generates similar results to those provided by the conventional annealing process. The approach was effectively applied to graphene-based inverted OSCs with notable power conversion efficiencies of 8.16% and 7.41% on the solid and flexible substrates, respectively, which promises the great feasibility of graphene for emerging optoelectronic device applications.

Solution-Processed n-Type Graphene Doping for Cathode in Inverted Polymer Light-Emitting Diodes

n-Type doping with (4-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl) dimethylamine (N-DMBI) reduces a work function (WF) of graphene by ∼0.45 eV without significant reduction of optical transmittance. Solution process of N-DMBI on graphene provides effective n-type doping effect and air-stability at the same time. Although neutral N-DMBI act as an electron receptor leaving the graphene p-doped, radical N-DMBI acts as an electron donator leaving the graphene n-doped, which is demonstrated by density functional theory. We also verify the suitability of N-DMBI-doped n-type graphene for use as a cathode in inverted polymer light-emitting diodes (PLEDs) by using various analytical methods. Inverted PLEDs using a graphene cathode doped with N-DMBI radical showed dramatically improved device efficiency (∼13.8 cd/A) than did inverted PLEDs with pristine graphene (∼2.74 cd/A). N-DMBI-doped graphene can provide a practical way to produce graphene cathodes with low WF in various organic optoelectronics.

Multilayer Graphene with Chemical Modification as Transparent Conducting Electrodes in Organic Light-Emitting Diode

Graphene is a promising candidate for the replacement of the typical transparent electrode indium tin oxide in optoelectronic devices. Currently, the application of polycrystalline graphene films grown by chemical vapor deposition is limited for their low electrical conductivity due to the poor transfer technique. In this work, we developed a new method of preparing tri-layer graphene films with chemical modification and explored the influence of doping and patterning process on the performance of the graphene films as transparent electrodes. In order to demonstrate the application of the tri-layer graphene films in optoelectronics, we fabricated the organic light-emitting diodes (OLEDs) based on them and found that plasma etching is feasible with certain influence on the quality of the graphene films and the performance of the OLEDs.

Graphene-Based Three-Dimensional Capacitive Touch Sensor for Wearable Electronics

The development of input device technology in a conformal and stretchable format is important for the advancement of various wearable electronics. Herein, we report a capacitive touch sensor with good sensing capabilities in both contact and noncontact modes, enabled by the use of graphene and a thin device geometry. This device can be integrated with highly deformable areas of the human body, such as the forearms and palms. This touch sensor detects multiple touch signals in acute recordings and recognizes the distance and shape of the approaching objects before direct contact is made. This technology offers a convenient and immersive human-machine interface and additional potential utility as a multifunctional sensor for emerging wearable electronics and robotics.

Direct Free Carrier Photogeneration in Single Layer and Stacked Organic Photovoltaic Devices

High performance organic photovoltaic devices typically rely on type-II P/N junctions for assisting exciton dissociation. Heremans and co-workers recently reported a high efficiency device with a third organic layer which is spatially separated from the active P/N junction; but still contributes to the carrier generation by passing its energy to the P/N junction via a long-range exciton energy transfer mechanism. In this study the authors show that there is an additional mechanism contributing to the high efficiency. Some bipolar materials (e.g., subnaphthalocyanine chloride (SubNc) and subphthalocyanine chloride (SubPc)) are observed to generate free carriers much more effectively than typical organic semiconductors upon photoexcitation. Single-layer devices with SubNc or SubPc sandwiched between two electrodes can give power conversion efficiencies 30 times higher than those of reported single-layer devices. In addition, internal quantum efficiencies (IQEs) of bilayer devices with opposite stacking sequences (i.e., SubNc/SubPc vs SubPc/SubNc) are found to be the sum of IQEs of single layer devices. These results confirm that SubNc and SubPc can directly generate free carriers upon photoexcitation without assistance from a P/N junction. These allow them to be stacked onto each other with reversible sequence or simply stacking onto another P/N junction and contribute to the photocarrier generation.

Surface Charge Transfer Doping of Low-Dimensional Nanostructures toward High-Performance Nanodevices

Device applications of low-dimensional semiconductor nanostructures rely on the ability to rationally tune their electronic properties. However, the conventional doping method by introducing impurities into the nanostructures suffers from the low efficiency, poor reliability, and damage to the host lattices. Alternatively, surface charge transfer doping (SCTD) is emerging as a simple yet efficient technique to achieve reliable doping in a nondestructive manner, which can modulate the carrier concentration by injecting or extracting the carrier charges between the surface dopant and semiconductor due to the work-function difference. SCTD is particularly useful for low-dimensional nanostructures that possess high surface area and single-crystalline structure. The high reproducibility, as well as the high spatial selectivity, makes SCTD a promising technique to construct high-performance nanodevices based on low-dimensional nanostructures. Here, recent advances of SCTD are summarized systematically and critically, focusing on its potential applications in one- and two-dimensional nanostructures. Mechanisms as well as characterization techniques for the surface charge transfer are analyzed. We also highlight the progress in the construction of novel nanoelectronic and nano-optoelectronic devices via SCTD. Finally, the challenges and future research opportunities of the SCTD method are prospected.

Graphene-Based Flexible and Stretchable Electronics

Graphene provides outstanding properties that can be integrated into various flexible and stretchable electronic devices in a conventional, scalable fashion. The mechanical, electrical, and optical properties of graphene make it an attractive candidate for applications in electronics, energy-harvesting devices, sensors, and other systems. Recent research progress on graphene-based flexible and stretchable electronics is reviewed here. The production and fabrication methods used for target device applications are first briefly discussed. Then, the various types of flexible and stretchable electronic devices that are enabled by graphene are discussed, including logic devices, energy-harvesting devices, sensors, and bioinspired devices. The results represent important steps in the development of graphene-based electronics that could find applications in the area of flexible and stretchable electronics.

A Transparent Antipeep Piezoelectric Nanogenerator to Harvest Tapping Energy on Screen

Aligning PbZr(0.52)Ti(0.48)O3 (PZT) nanowires in polydimethylsiloxane introduces dielectrophoresis, improving the electromechanical properties of nanogenerators, and the light transmittance of composite films. A novel transparent and antipeep piezoelectric nanogenerator is developed that can be used for harvesting the energy from the light tapping of a finger on a cell phone, with an output current of 0.8 nA.

Graphene as Transparent Electrodes: Fabrication and New Emerging Applications

Graphene has been regarded as a promising candidate for a new generation of transparent electrodes (TEs) due to its prominent characteristics including high optical transmittance, exceptional electronic transport, outstanding mechanical strength, and environmental stability. Comprehensive and critical insights into the latest advances in graphene-based TEs (GTEs) since, but not limited to 2013, are provided, with an emphasis on fabrication, modification, and versatile applications. Several emerging application areas not previously summarized, including electrochromic devices, supercapacitors, electrochemical and electrochemiluminescent sensors, are discussed in detail. The challenges and prospects in these fields are also addressed.

Synthesis and applications of carbon nanomaterials for energy generation and storage

The world is facing an energy crisis due to exponential population growth and limited availability of fossil fuels. Over the last 20 years, carbon, one of the most abundant materials found on earth, and its allotrope forms such as fullerenes, carbon nanotubes and graphene have been proposed as sources of energy generation and storage because of their extraordinary properties and ease of production. Various approaches for the synthesis and incorporation of carbon nanomaterials in organic photovoltaics and supercapacitors have been reviewed and discussed in this work, highlighting their benefits as compared to other materials commonly used in these devices. The use of fullerenes, carbon nanotubes and graphene in organic photovoltaics and supercapacitors is described in detail, explaining how their remarkable properties can enhance the efficiency of solar cells and energy storage in supercapacitors. Fullerenes, carbon nanotubes and graphene have all been included in solar cells with interesting results, although a number of problems are still to be overcome in order to achieve high efficiency and stability. However, the flexibility and the low cost of these materials provide the opportunity for many applications such as wearable and disposable electronics or mobile charging. The application of carbon nanotubes and graphene to supercapacitors is also discussed and reviewed in this work. Carbon nanotubes, in combination with graphene, can create a more porous film with extraordinary capacitive performance, paving the way to many practical applications from mobile phones to electric cars. In conclusion, we show that carbon nanomaterials, developed by inexpensive synthesis and process methods such as printing and roll-to-roll techniques, are ideal for the development of flexible devices for energy generation and storage - the key to the portable electronics of the future.

Roll-to-roll printed silver nanowires for increased stability of flexible ITO-free organic solar cell modules

We report the use of roll-to-roll printed silver nanowire networks as front electrodes for fully roll-to-roll processed flexible indium-tin-oxide (ITO) free OPV modules. We prepared devices with two types of back electrodes, a simple

PEDOT

PSS back electrode and a

PEDOT

PSS back electrode with a printed silver grid in order to simultaneously explore the influence of the back electrode structure on the operational stability of the modules that did not include any UV-protection. We subjected the devices to stability testing under a number of protocols recommended by the international summit on OPV stability (ISOS). We explored accelerated ISOS-D-2, ISOS-D-3, ISOS-L-2, ISOS-L-3, ISOS-O-1 and ISOS-O-2 testing protocols and compared the performance to previous reports employing the same testing protocols on devices with

PEDOT

PSS instead of the silver nanowires in the front electrode. We find significantly increased operational stability across all ISOS testing protocols over the course of the study and conclude that replacement of

PEDOT

PSS in the front electrode with silver nanowires increase operational stability by up to 1000%. The duration of the tests were in the range of 140-360 days. The comparison of front and back electrode stability in this study shows that the modules with silver nanowire front electrodes together with a composite back electrode comprising

PEDOT

PSS and a silver grid present the best operational stability.

Cascade donor–acceptor organic ferroelectric layers, between graphene sheets, for solar cell applications

Organic ferroelectric layers sandwiched between the graphene sheets are presented as a model of the solar cell.

Ultraviolet photoconductive devices with an n-GaN nanorod-graphene hybrid structure synthesized by metal-organic chemical vapor deposition

The superior photoconductive behavior of a simple, cost-effective n-GaN nanorod (NR)-graphene hybrid device structure is demonstrated for the first time. The proposed hybrid structure was synthesized on a Si (111) substrate using the high-quality graphene transfer method and the relatively low-temperature metal-organic chemical vapor deposition (MOCVD) process with a high V/III ratio to protect the graphene layer from thermal damage during the growth of n-GaN nanorods. Defect-free n-GaN NRs were grown on a highly ordered graphene monolayer on Si without forming any metal-catalyst or droplet seeds. The prominent existence of the undamaged monolayer graphene even after the growth of highly dense n-GaN NRs, as determined using Raman spectroscopy and high-resolution transmission electron microscopy (HR-TEM), facilitated the excellent transport of the generated charge carriers through the photoconductive channel. The highly matched n-GaN NR-graphene hybrid structure exhibited enhancement in the photocurrent along with increased sensitivity and photoresponsivity, which were attributed to the extremely low carrier trap density in the photoconductive channel.

Observing electron extraction by monolayer graphene using time-resolved surface photoresponse measurements

Graphene is considered a next-generation electrode for indium tin oxide (ITO)-free organic photovoltaic devices (OPVs). However, to date, limited numbers of OPVs containing surface-modified graphene electrodes perform as well as ITO-based counterparts, and no devices containing a bare graphene electrode have been reported to yield satisfactory rectification characteristics. In this report, we provide experimental data to learn why. Time-resolved surface photoresponse measurements on templated pentacene-on-graphene films directly reveal that p-doped monolayer graphene efficiently extracts electrons, not holes, from photoexcited pentacene. Accordingly, a graphene/pentacene/MoO3 heterojunction displays a large surface photoresponse and, by inference, efficient dissociation of photogenerated excitons, with graphene serving as an electron extraction layer and MoO3 as a hole extraction layer. In contrast, a graphene/pentacene/C60 heterojunction yields a comparatively insignificant surface photoresponse because both graphene and C60 act as competing electron extraction layers. The data presented herein provide experimental insight for future endeavors involving bare graphene as an electrode for organic photovoltaic devices and strongly suggest that p-doped graphene is best considered a cathode for OPVs.

Flexible graphene based microwave attenuators

We demonstrate flexible 3 dB and 6 dB microwave attenuators using multilayer graphene grown by the chemical vapor deposition method. On the basis of the characterized results of multilayer graphene and graphene-Au ohmic contacts, the graphene attenuators are designed and measured. The flexible graphene-based attenuators have 3 dB and 6 dB attenuation with a return loss of less than -15 dB at higher than 5 GHz. The devices have shown durability in a bending cycling test of 100 times. The circuit model of the attenuator based on the characterized results matches the experimental results well.

Epoxy/graphene nanocomposites – processing and properties: a review

Graphene, a 2D fullerene, is a unique material because of its exceptional set of properties. This review has been focused on the processing methods and mechanical, electrical, thermal, and fire retardant properties of epoxy/graphene nanocomposites.

Functionalized graphene and other two-dimensional materials for photovoltaic devices: device design and processing

2D materials have been successfully used in various types of solar cells as transparent electrodes, interfacial and active materials.

Plasmonic organic solar cell employing Au NP:PEDOT:PSS doped rGO

We report a comprehensive study of the influence of NPs on organic solar cells by introducing Au NPs into OSCs fabricated using PEDOT:PSS:rGO. The PEDOT:PSS:rGO embedded with Au NPs had better J_sc and PCE values than the control devices.

High-Volume Processed, ITO-Free Superstrates and Substrates for Roll-to-Roll Development of Organic Electronics

The fabrication of substrates and superstrates prepared by scalable roll-to-roll methods is reviewed. The substrates and superstrates that act as the flexible carrier for the processing of functional organic electronic devices are an essential component, and proposals are made about how the general availability of various forms of these materials is needed to accelerate the development of the field of organic electronics. The initial development of the replacement of indium-tin-oxide (ITO) for the flexible carrier materials is described and a description of how roll-to-roll processing development led to simplification from an initially complex make-up to higher performing materials through a more simple process is also presented. This process intensification through process simplification is viewed as a central strategy for upscaling, increasing throughput, performance, and cost reduction.