Vertical Separation Research Articles

Downward Homogenized Crystallization for Inverted Wide‐Bandgap Mixed‐Halide Perovskite Solar Cells with 21% Efficiency and Suppressed Photo‐Induced Halide Segregation

AbstractMixed‐halide perovskite has an irreplaceable role as wide‐bandgap absorber in multi‐junction tandem solar cells. However, large open‐circuit voltage (Voc) loss due to non‐uniform halide distribution and compromised device stability due to photo‐induced halide segregation has significantly limited the applications. Here, it is introduced 4‐(2‐aminoethyl)‐benzenesulfonyl fluoride hydrochloride (ABF) with multifunctional groups (sulfonyl, ammonium, and fluoride) to the mixed‐halide precursor to demonstrate a downward homogenized crystallization strategy for suppressing the initial vertical halide phase separation during perovskite crystallization and reducing Voc loss. Furthermore, fluoride with strong electronegativity effectively fixes anions and cations, while sulfonyl and ammonium are used to passivate positive charged (halide vacancies) and negative charged (FA/MA vacancies) defects, respectively, thereby reducing the generation of ion vacancies that lead to subsequent photo‐induced halide segregation. As a result, the 1.63 and 1.68 eV wide‐bandgap perovskite solar cells with inverted structures exhibit the champion power conversion efficiency (PCE) of 21.76% and 20.11% with Voc of 1.18 and 1.21 V, respectively. Most importantly, the optimized devices without encapsulation preserve 86% of initial efficiency after 240 h of continuous illumination under AM 1.5G, showing excellent light stability. Thus, the homogenized crystallization strategy provides highly efficient performance and stability for future tandem solar cell applications.

Significant effect of synthesis methodologies of metal-organic frameworks upon the additively manufactured dual-mode triboelectric nanogenerator towards self-powered applications

Triboelectric nanogenerators (TENG) is an effective approach for the development of self-powered systems, as it offers several flexibilities, such as wide material choice, high power density, simple fabrication process, etc. In this present work, the zeolite imidazole framework (ZIF-8) is synthesized by two approaches: solvent-assisted (SA) and solvent-free (HG), and explored its applicability in TENG devices for energy harvesting. The formation of the highly crystalline ZIF-8 is established from structural and morphological studies. An attempt has been made to understand the surface roughness and surface potential of the synthesized materials that could directly fit their scopes in the addition of the conventional triboelectric series due to their positive surface potential. A cost-effective and facile approach of re-using the waste 3D printing parts is attempted to design vertical contact separation and single electrode mode TENG. The correlation between the material’s properties, such as surface potential and surface roughness, supports the ZIF-8 (HG)/Kapton-based dual-mode TENG device to deliver higher electrical output. The triple-unit TENG was designed and fabricated using an additive manufacturing route to achieve a voltage of 150 V and a current of 4.95 µA. Further, both the dual-mode TENG devices are demonstrated to explore self-powered applications by integration with robotics tilt table and biomechanical energy harvesting.

Safety performance functions to predict separation minima infringements in en-route airspace

PurposeThe purpose of this study is to establish a systematic framework to characterise the safety of air routes, in terms of separation minima infringements (SMIs) between en-route aircraft, based on the definition of models known as safety performance functions.Design/methodology/approachTechniques with high predictive capability were selected that enable both expert knowledge and data to be harnessed: Bayesian networks. It was necessary to establish a conceptual framework that integrates the knowledge currently available on the causality and precursors of SMIs with the hindsight derived from the analysis of the type of data available. To translate the conceptual framework into a set of causal subnets, the concepts of air traffic management (ATM) barrier model and event trees have been incorporated.FindingsThe model combines analytics and insights, as well as predictive capability, to answer the question of how airspace separation infringements are produced and what their frequency of occurrence will be. The main outputs of the network are the predicted probability of success for the ATM barriers and the predicted probability distribution of the vertical and horizontal separation of an aircraft in its closest point of approach.Originality/valueThe main contribution of this work is that, by virtue of the calculation capacity obtained, the network can be used to draw conclusions about the impact that a modification of the airspace and of the traffic, or operational conditions, would have on the effectiveness of the barriers and on the final distributions of distance between aircraft in the CPA, thereby estimating the probability of SMI.

Insulating Polymer Blend Organic Thin-Film Transistors Based on Bilayer-Type Alkylated Benzothieno[3,2-b]naphtho[2,3-b]thiophene.

Herein, we developed a practical method to produce high-performance organic thin-film transistors (OTFTs) based on highly layered crystalline organic semiconductors (OSCs) that form bilayer-type layered herringbone (b-LHB) packing and exhibit high intrinsic mobility. We applied the insulating polymer blend technique using a typical b-LHB OSC of 2-octyl-benzothieno[3,2-b]naphtho[2,3-b]thiophene (2-C8-BTNT) and fabricated polycrystalline thin-film transistors (TFTs) via short-duration spin coating and subsequent annealing. The use of blends and the choice of polymer additive strongly affected the performance of the polycrystalline TFTs, and poly(methyl methacrylate) (PMMA) blend TFTs exhibited a high mobility exceeding 4 cm2/(V s) and small device-to-device variations. Using extended techniques in atomic force microscopy (AFM), we investigated the thin-film morphologies by bimodal AFM and the carrier transport properties by Kelvin probe force microscopy (KPFM). We demonstrated that the PMMA blend system enables the formation of a well-ordered polycrystalline thin film induced by vertical phase separation between the OSC and PMMA over a large area, resulting in uniform TFT performance. These findings pave the way for obtaining high-performance TFTs using simple processes, representing a substantial advancement toward the realization of printed electronics.

『도헌』의 법률적 구성과 제도적 장치 연구

The purpose of this study is to analyze the ideological background, legal composition, and separation of powers contained within the institutional devices of The Dao Constitution based on the basic principles of the legal system, which would be embodied in The Constitution of the Republic of Korea. The ideological background of The Dao Constitution is that of the religion, Daesoon Jinrihoe. In Daesoon Jinrihoe, it is held that the Supreme God, Sangje, determined that Mutual Contention, the ruling pattern of the Former World, ran contrary to His divine will and this endangered the world as nature and humans had also fallen into Mutual Contention. As an act of divine intervention, Sangje established Mutual Beneficence so that nature and humanity could follow Mutual Beneficence as a paradigm shift culminating in a Great Opening of the universe. Sangje, the agent behind the paradigm shift, revealed His divine will that humans transform into mutually beneficent humans. Therefore, The Dao Constitution was written to be a set of fundamental norms based on the ‘rights and obligations of the members of Daesoon Jinrihoe’ to accept and implement the will of Sangje as it applies to each member’s mission. The legal composition of The Dao Constitution consists of the body and supplementary provisions. The text consists of general rules, moral rights and obligations, origins, and institutional devices. Institutional devices include the Central Council, the Institute of Propagation and Edition, the Institute of Religious Services, Works, Financial Management, and the Institute of Audit and Inspection. The legal composition of The Dao Constitution is similar to that of the Constitution. The difference is that while the Constitution applies a ‘principle of maximum rights and minimum obligations,’ The Dao Constitution stipulates more obligations than rights in order to complete the mission of the members. The principle of separation of powers is applied to the institutional devices in The Dao Constitution. In The Dao Constitution, the organizational form of the central headquarters has been divided into a ‘before and after’ scheme surrounding the death of Dojeon. The organizational form of the central headquarters prior to Dojeon’s death was similar to a Constitutional Monarchy. After the death of Dojeon, the central headquarters’ organizational form became similar to a parliamentary cabinet system. The separation of powers at central headquarters is divided among a legislative power (the Central Council), an executive power (the Institute of Religious Services), and a judicial power (the Institute of Audit and Inspection). The separation of powers within the functions of the central government first occurs between the Central Council and its employees, then between the Central Council and the Institute of Auditing and Inspection, and also between the Legislative Government and the Institute of Religious Services. Furthermore, the principle of a vertical separation of powers exists between the central headquarters and the local organization.

High-Detail Fault Segmentation: Deep Insight into the Anatomy of the 1983 Borah Peak Earthquake Rupture Zone (Mw 6.9, Idaho, USA)

Abstract Following observations made in a survey campaign along the Lost River Fault (Idaho, USA) in 2019, we integrate both original and previously published data to obtain a detailed segmentation of the fault sections that failed in the 1983 Borah Peak earthquake (Mw 6.9). The earthquake ruptured the topographic surface with an oblique-normal faulting mechanism, activating two SW-dipping fault segments (Thousand Springs and Warm Springs) and a branching SSW-dipping fault (Arentson Gulch Fault) and producing coseismic surface ruptures with up to 3 m of vertical separation. We augment the 1983 earthquake description by interpreting high-resolution topography and fault mapping. We use quality vertical separation data, rupture zone width measurements, and fault slip data to analyze major and minor structural-geometric complexities, highlighting a partition of the deformation and a fault segmentation into four detail levels (i.e., segments, sections, subsections, and sectors). Our work provides new details of the 1983 Borah Peak earthquake, constraints for paleoseismic and seismotectonic studies, and a methodological approach applicable in other areas of the world. Our fault-slip data show variations along fault-strike that we interpret as kinematic partitioning. In 1983, the main southern segment had a large rupture zone width, while the northern segment localized the deformation. The distributed ruptures accommodate a large portion of the rupture length (~19.5 km versus 31 km for the main rupture) and displacement (~66%). 83% of the surface faulting and 80% of the displacement are located at the hanging wall of the main rupture. There is a strong correlation between vertical separation, rupture zone width, rupture position (footwall or hanging wall), and fault geometry. We highlight the control of the obliquity and kinematic partitioning in the surface expression of the earthquake propagation. We interpret the coseismic (i.e., 1983) and long-term (i.e., Quaternary) behavior, showing that the two activated segments had similar cumulated behaviors in distributing the deformation between synthetic and antithetic ruptures, despite the different geometries. Our results have implications for fault rupture behavior with application to rupture hazard.

Wavefield separation using irreversible-migration filtering

Wavefield separation is important for eliminating unwanted components of seismic data while retaining preferred components therein; however, there have been difficulties with using traditional methods to select a proper muting window in the transformed domain. A narrow muting window can separate different components well, but it causes visible artifacts due to sudden truncations (e.g., the Gibbs phenomenon), whereas a wide muting window would, on the other hand, leave unwanted components. We have adopted separating the wavefield based on its irreversibility after migration and demigration. One-way wave-equation migration would automatically damp high-slope components in the evanescent region while accurately handling the other components. Thus, the migration velocity can be tuned to naturally trap a given range of high-slope components into the evanescent region in the migrated domain, which would be irreversible after demigration. In contrast, the other components (i.e., those outside the evanescent region) can be recovered after demigration. Our method achieves perfect muting by taking advantage of migration and demigration, and thus it avoids the manual operation of setting a muting window. As a result, our method is free of muting artifacts. We conduct numerical experiments with synthetic and field data, and the results verify the excellent performance of our method for several different kinds of wavefield separation, including linear event separation, structural noise elimination, diffraction-reflection separation, and vertical seismic profile wavefield separation. Our method integrates noise reduction and the wavefield separation, and thus it can reduce the computational cost of using different data processing schemes and avoid the related potential error accumulation.

The Impact of Benzothiadiazole on the Optoelectronic Performance of Polymer/PC71BM Blend Films and Their Application in NIR Phototransistors

AbstractD‐A conjugated polymers P1 and P2 are synthesized by copolymerizing bisthiophene‐fused diketopyrrolopyrrole (4,11‐bis(2‐decyltetradecyl)‐7H,14H‐thieno[3',2':7,8]‐indolizino[2,1‐a]thieno[3,2‐g]indolizine‐7,14‐dione, BTI) with terthiophene and thiophene‐benzothiadiazole‐thiophene, respectively. Molecular packing is characterized by X‐ray diffraction. The film morphology is characterized by atomic force and scanning electron microscopy. The vertical phase separation is characterized by XPS. The mechanism of film morphology formation is explained from intermolecular interaction, kinetics, and surface free energy. The spin‐coated films of polymers blended with PC71BM are served as semiconductor layers in near‐infrared (NIR) phototransistors. The impact of morphology on optoelectronic performance is analyzed. The mobility of organic field effect transistors based on P1 or P2 thin films remains constant with the addition of PC71BM with weight ratio being less than 50%. The main reason is that π–π stacking in both P1 and P2 thin films is at all directions and PC71BM does not disturb the charge percolation path. Benzothiadiazole in P2 enables stronger mutual attraction between P2 and PC71BM, and therefore large contact area between P2 and PC71BM forms in the heterojunction. The photoresponsivity improves by 2 times for NIR phototransistors based on P2/PC71BM when decreasing light intensity from 63 to 1.8 µW cm‐2. The above results suggest a feasible conjugated polymer design rule for high sensitivity NIR phototransistors.

Volume Transport by a 3D Quasigeostrophic Heton

Oceanic flows self-organize into coherent vortices, which strongly influence their transport and mixing properties. Counter-rotating vortex pairs can travel long distances and carry trapped fluid as they move. These structures are often modeled as hetons, viz. counter-rotating quasigeostrophic point vortex pairs with equal circulations. Here, we investigate the structure of the transport induced by a single three-dimensional heton. The transport is determined by the Hamiltonian structure of the velocity field induced by the heton’s component vortices. The dynamics display a sequence of bifurcations as one moves through the heton-induced velocity field in height. These bifurcations create and destroy unstable fixed points whose associated invariant manifolds bound the trapped volume. Heton configurations fall into three categories. Vertically aligned hetons, which are parallel to the vertical axis and have zero horizontal separation, do not move and do not transport fluid. Horizontally aligned hetons, which lie on the horizontal plane and have zero vertical separation, have a single parameter, the horizontal vortex half-separation Y, and simple scaling shows the dimensional trapped volume scales as Y3. Tilted hetons are described by two parameters, Y and the vertical vortex half-separation Z, rendering the scaling analysis more complex. A scaling theory is developed for the trapped volume of tilted hetons, showing that it scales as Z4/Y for large Z. Numerical calculations illustrate the structure of the trapped volume and verify the scaling theory.

Structural styles and linkage evolution in the middle segment of a strike-slip fault: A case from the Tarim Basin, NW China

The structural geometric and kinematic analysis of the Shunbei No. 5 fault zone (fault SB5) in the Tarim Basin was conducted based on the fault interpretation on the three-dimensional (3D) seismic sections and coherence slices of several seismic reflecting surfaces in the study area. The fault SB5 evolution model was recovered using the fault pattern analyses and palaeostress reconstruction, which required factors like the width of the damage zone, maximum throw of the main fault, vertical separation, and the shear crack angle along the fault zone. The results show that: (1) Four tectonic layers in the vertical direction are identified according to the difference of structure style, divided by the top and bottom of the Cambrian salt rocks, and the top surface of the Ordovician carbonate. (2) Strike-slip faults in the study area are the middle segment of the large strike-slip fault zone composed of major faults and overlap zones; 11 stepovers in the study area can be classified into three types according to their geometric characteristics. Strain concentration appears on the overlap zone under the continuous shear stress field and shows high activity. Fault SB5 has undergone three major evolutionary stages: the transpressional stage in the Middle Ordovician, the dextral shearing stage in the Early Silurian, and the final evolutionary sinistral process in the Late Devonian.

Balancing the Molecular Aggregation and Vertical Phase Separation in the Polymer: Nonfullerene Blend Films Enables 13.09% Efficiency of Organic Solar Cells with Inkjet‐Printed Active Layer

AbstractDrop‐on demand inkjet‐printing (IJP) is a deposition technique with promise in the context of fabricating large‐area organic solar cells (OSCs) because of its high material usage, direct‐pattern, and large‐area roll‐to‐roll printing compatibility. But its feature of drop‐to‐drop deposition during IJP makes the film's drying and phase separation process different from spin‐coating, and forms different nanophase separation and vertical phase separation morphology. In this work, the nanophase separation of the inkjet‐printed organic blend films is systematically studied at different substrate temperatures. The results reveal that increasing the substrate temperature can suppress excess molecules aggregation owing to the high drying speed, leading to improved exciton dissociation efficiency in the blend films. However, the quick drying process at high temperature also leads to a homogenous vertical phase separation, which is not ideal for charge collection. Instead of printing the mixture of donor and acceptor solution directly to form the bulk‐heterojunction structure, the polymer donor is printed on the top of the acceptor surface, a so‐called layer‐by‐layer inkjet printing (LBL‐IJP) process. By using this LBL‐IJP route, balanced nanoscale phase aggregation and gradient vertical phase separation morphology are achieved, which leads to a record power conversion efficiency of 13.09% for the OSCs with an inkjet‐printed active layer.

Locking Energy Transfer of Rare Earth Ions via an “Electron Jam” Caused by Vertical Photocarrier Separation of a Layered Semiconductor

Energy transfer (ET) of trivalent rare earth (RE)-doped inorganic crystals has been investigated comprehensively from theory to technology; however, the influence of photocarrier transmission has been considered impossible, as the 4f electrons of RE ions are shielded well from outer electrons. Here, on the basis of an anisotropic Bi3O4Cl layered semiconductor, we report for the first time the ET phenomenon of an Er3+–Yb3+ codoped system locked by photocarrier separation. When the photocarrier of the layered host is separated efficiently under a vertical spontaneous interelectric field, the ET and energy-back-transfer (EBT) between Er3+ and Yb3+ ions can be inhibited completely; otherwise, they can occur as usual. Consequently, the Yb3+ ion dopant mainly acts as a quencher for 980 nm-excited visible upconversion (UC) and infrared emission of Er3+ ions, and the cross-relaxation between Er3+ and Yb3+ ions via EBT is inhibited simultaneously. We show that the separated photoholes on the surface can suppress the recombination of excited electrons of Er3+ ions to the ground level, leading to a special “electron jam” on intermediate levels, which prevents the acceptance of excited electrons further via either the ET or EBT process. The result of our current work greatly enhances the understanding of ET behavior of RE ions and the material structure of RE-doped materials.

Wearable Human Motion Monitoring Using Vertical Contact Separation Mode Triboelectric Nanogenerator

Wearable human motion monitoringhas become an integral part of the paradigm shift that is on the horizon in the field of healthcare for a wide variety of biomedical applications. In recent years, there has been incessant advancement in smart wearable technology capable of human motion monitoring ranging from strain sensors to piezoelectrics. This paper proposes to fabricate a Triboelectric Nanogenerator based on Vertical Contact Separation (VCS) mode with design characteristics offlexibility, low cost, simple and easy to fabricate design for real - time monitoring of human body movements. The output performance of fabricated VCS - TENG is analysed by finger tapping. In order to conduct human motion monitoring, VCS - TENG is affixed on different body parts, and the corresponding signal is analysed. The developed prototype can be further integrated with advanced electronics to deliver promising technology in the field of healthcare diagnostics and monitoring.

Machine Learning classification techniques applied to static air traffic conflict detection

This article evaluates Machine Learning (ML) classification techniques applied to air-traffic conflict detection. The methodology develops a static approach in which the conflict prediction is performed when an aircraft pierces into the airspace. Conflict detection does not evaluate separation infringements but a Situation of Interest (SI). An aircraft pair constitutes a SI when it is expected to get with a horizontal separation between both aircraft closer than 10 Nautical Miles (NM) and a vertical separation closer than 1000 feet (ft). Therefore, the ML predictor classifies aircraft pairs between SI or No SI pairs. Air traffic information is extracted from The OpenSky Network that provides ADS-B trajectories. ADS-B trajectories do not offer enough SI samples to be evaluated. Hence, the authors performed simulations varying the entry time of the trajectories to the airspace within the same time period. The methodology was applied to a portion of Switzerland airspace, and simulations reached a 5% rate of SI samples. Cost-sensitive techniques were used to handle the strong imbalance of the database. Two experiments were performed: the Pure model considered the whole database, and the Hybrid model considered aircraft pairs that intersect horizontally closer than 20 NM and vertically lower than 1000 ft. The Hybrid model provided the best results achieving 72% recall, representing the success rate of Missed alerts and 82% accuracy, which means the whole predictions’ success rate.

Ternary Blend Organic Solar Cells: Understanding the Morphology from Recent Progress.

Ternary blend organic solar cells (TB-OSCs) incorporating multiple donor and/or acceptor materials into the active layer have emerged as a promising strategy to simultaneously improve the overall device parameters for realizing higher performances than binary devices. Whereas introducing multiple materials also results in a more complicated morphology than their binary blend counterparts. Understanding the morphology is crucially important for further improving the device performance of TB-OSC. This review introduces the solubility and miscibility parameters that affect the morphology of ternary blends. Then, this review summarizes the recent processes of morphology study on ternary blends from the aspects of molecular crystallinity, molecular packing orientation, domain size and purity, directly observation of morphology, vertical phase separation as well as morphological stability. Finally, summary and prospects of TB-OSCs are concluded.

Phylogenetic divergence and adaptation of Nitrososphaeria across lake depths and freshwater ecosystems.

Thaumarchaeota (now the class Nitrososphaeria in the phylum Thermoproteota in GTDB taxonomy) are abundant across marine and soil habitats; however, their genomic diversity and evolutionary history in freshwater environments remain elusive. Here, we reconstructed 17 high-quality metagenome-assembled genomes of Nitrososphaeria from a deep lake and two great rivers, and compared all available genomes between freshwater and marine habitats regarding their phylogenetic positions, relative abundance, and genomic content. We found that freshwater Nitrososphaeria were dominated by the family Nitrosopumilaceae and could be grouped into three distinct clades closely related to the genera Nitrosopumilus, Nitrosoarchaeum, and Nitrosotenuis. The Nitrosopumilus-like clade was exclusively from deep lakes, while the Nitrosoarchaeum-like clade was dominated by species from deep lakes and rivers, and the Nitrosotenuis-like clade was mainly from rivers, deep lakes, and estuaries. Interestingly, there was vertical niche separation between two clades in deep lakes, showing that the Nitrosopumilus-like species dominated shallow layers, whereas the relative abundance of the Nitrosoarchaeum-like clade increased toward deep waters. Phylogenetic clustering patterns in the Nitrosopumilaceae supported at least one freshwater-to-marine and two marine-to-freshwater transitions, the former of which refined the potential terrestrial-to-marine evolutionary path as previously proposed. The occurrence of the two marine-to-freshwater transitions were accompanied by horizontal transfer of the genes involved in nutrition regulation, osmoregulation, and cell motility during their colonization to freshwater habitats. Specifically, the Nitrosopumilus-like clade showed losses of genes encoding flagella assembly and ion transport, whereas the Nitrosoarchaeum-like clade had losses of intact genes involved in urea uptake and utilization and gains of genes encoding osmolarity-mediated mechanosensitive channels. Collectively, our results reveal for the first time the high genomic diversity of the class Nitrososphaeria across freshwater ecosystems and provide novel insights into their adaptive mechanisms and evolutionary histories.

Volatile Solid Additive-Assisted Sequential Deposition Enables 18.42% Efficiency in Organic Solar Cells.

Morphology optimization of active layer plays a critical role in improving the performance of organic solar cells (OSCs). In this work, a volatile solid additive‐assisted sequential deposition (SD) strategy is reported to regulate the molecular order and phase separation in solid state. The OSC adopts polymer donor D18‐Cl and acceptor N3 as active layer, as well as 1,4‐diiodobenzene (DIB) as volatile additive. Compared to the D18‐Cl:N3 (one‐time deposition of mixture) and D18‐Cl/N3 (SD) platforms, the D18‐Cl/N3(DIB) device based on DIB‐assisted SD method exhibits a finer phase separation with greatly enhanced molecular crystallinity. The optimal morphology delivers superior charge transport and extraction, offering a champion power conversion efficiency of 18.42% with significantly enhanced short‐circuit current density (J sc) of 27.18 mA cm−2 and fill factor of 78.8%. This is one of the best performances in binary SD OSCs to date. Angle‐dependent grazing‐incidence wide‐angle X‐ray scattering technique effectively reveals the vertical phase separation and molecular crystallinity of the active layer. This work demonstrates the combination of volatile solid additive and sequential deposition is an effective method to develop high‐performance OSCs.

1-Chloronaphthalene-Induced Donor/Acceptor Vertical Distribution and Carrier Dynamics Changes in Nonfullerene Organic Solar Cells and the Governed Mechanism.

Electron donors and acceptors in organic solar cells (OSCs) shall strike a favorable vertical phase separation that acceptors and donors have sufficient contact and gradient accumulation near the cathodes and anodes, respectively. Random mixing of donors/acceptors at surface will result in charge accumulation and severe recombination for low carrier-mobility organic materials. However, it is challenging to tune the vertical distribution in bulk-heterojunction films as they are usually made from a well-mixed donor/acceptor solution. Here, for the first time, it presents with solid evidence that the commonly used 1-chloronaphthalene (CN) additive can tune the donor/acceptor vertical distribution and establish the mechanism. Different from the previous understanding that ascribed the efficiency enhancement brought by CN to the improved molecular stacking/crystallization, it is revealed that the induced vertical distribution is the dominant factor leading to the significantly increased performance. Importantly, the vertical distribution tunability is effective in various hot nonfullerene OSC systems and creates more channels for the collection of dissociated carriers at corresponding organic/electrode interfaces, which contributes the high efficiency of 18.29%. This study of the material vertical distribution and its correlation with molecular stacking offers methods for additives selection and provides insights for the understanding and construction of high-performance OSCs.

The Regulatory Commitment Problem, Industry Structures and Investment Incentives in Network Quality Upgrades

This paper examines how the timing of access price regulation and the incumbent firm’s structure affect the investment incentives relating to network upgrades. We consider a general setting with non-ad-hoc specifications for the service quality and investment fixed cost functions, and we compare different possible scenarios for vertically integrated industry structures and the timing of regulatory actions. First, we show that the competition-investment trade-off may be solved when the regulator can fix the access price before the integrated network provider’s investment decision. Second, we show that the sole requirement of vertical separation on the incumbent firm is no guarantee for the viability of service-based competition, since foreclosure cannot be avoided in the absence of access price regulation. Third, we show that monopoly is socially preferable to retail competition when the investment spillover is high, and the regulator cannot commit ex-ante to the access price.

Microfluidic Screening-Assisted Machine Learning to Investigate Vertical Phase Separation of Small Molecule:Polymer Blend.

Solution-based thin-film processing is a widely utilized technique for the fabrication of various devices. In particular, the tunability of the ink composition and coating condition allows precise control of thin-film properties and device performance. Despite the advantage of having such tunability, the sheer number of possible combinations of experimental parameters render it infeasible to efficiently optimize device performance and analyze the correlation between experimental parameters and device performance. In this work, a microfluidic screening-embedded thin-film processing technique is developed, through which thin-films of varying ratios of small molecule semiconductor:polymer blend are simultaneously generated and screened in a time- and resource-efficient manner. Moreover, utilizing the thin-films of varying combinations of experimental parameters, machine learning models are trained to predict the transistor performance. Gaussian Process Regression (GPR) algorithms tuned by Bayesian optimization shows the best predictive accuracy amongst the trained models, which enables narrowing down of the combinations of experimental parameters and investigation of the degree of vertical phase separation under the predicted parameter space. The technique can serve as a guideline for elucidating the underlying complex parameter-property-performance correlations in solution-based thin-film processing, thereby accelerating the optimization of various thin-film devices in the future.