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Dropwise condensation (DWC) is a phenomenon of common occurrence and significant utility in nature and technology. In energy applications, sustenance of DWC and avoidance of transition to film formation is directly related to efficient heat removal, ensuring high performance of related devices and processes. The efficiency of heat transfer in DWC depends on the heat transfer rates of individual droplets and the droplet size distribution. While the former can be summarily captured in engineering analysis through thermal resistance modeling, the theoretical analysis of the droplet size distribution involves assumptions often oversimplifying the complexity of droplet interactions, especially in the important sub–10 μm regime. Here, a modeling framework based on the thermal resistance approach is coupled with a dynamic model of droplet interactions: Droplet growth, coalescence, jumping, and removal of condensate due to gravity are all present during the unfolding of the phenomenon to accurately predict the droplet size distribution. The motivation is condensation experiments on superhydrophobic surfaces, namely rough aluminum substrates with a hydrophobic coating. Through the “interaction” of computations with measurements, the experimental findings are explained and critical parameters for condensation heat transfer on superhydrophobic surfaces are illuminated. Although larger droplets can be easily observed in experiments, it is shown that large droplets do not significantly affect heat transfer after reaching such state of growth. Instead, it is the small (with radius < 10 μm) and what we term “shadowed” droplets, i.e., the droplets grown in the shadow of the vertical projection area of the larger droplets, that play an important role in the heat transfer process. Due to the growth of these droplets and their concomitant shadowed coalescence and ensuing re-nucleation, the shift in the droplet size distribution towards smaller sizes is significant-enough to render the heat transfer rate rather insensitive to the presence of large droplets. In this regime, the effect of contact angle hysteresis on heat transfer is not crucial. Through the comparison with measurements, the dominant role of the density of nucleation sites on heat transfer is revealed and an estimation of the density of sites (∼105 mm−2) as a function of subcooling is extracted. Finally, the distribution of sites is found critical for heat transfer; an ordered distribution of sites outperforms random and clustered distributions. ISSN:0017-9310 ISSN:1879-2189

The effect of cold atmospheric plasma (CAP) (45 kHz sinusoidal AC high voltage at 6 kV peak-to-peak for 5-15 min) and pulsed electromagnetic fields (PEMF) (amplitude 12.5 mT, repetitive frequency 3 Hz for 30 min) as pre-sowing treatments was studied on the germination, physiology, yield and quality characteristics of maize hybrid seeds with high and low germination capability. The measurements conducted during the plant growth were the dry weight, chlorophyll content, photosynthetic rate, transpiration rate and stomatal conductance, while for the harvested kernels, the color, texture, sphericity, size, ash, total protein and total crude content were estimated. The results showed that CAP and PEMF pre-sowing treatments favored the growth and physiology of both maize plants improving their germination rate significantly. Their chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance as well as dry weight were also improved. Both CAP and PEMF treatments, resulted in maize yield increase by 18-25% and by 10-20% compared to untreated samples for the low and high germination capability seeds, respectively. With regards to the quality of the harvested corn grains, their total protein and crude fiber content obtained by CAP treatment for 15 min were significantly increased by 26% and 29% for low germination seeds and by 36% and 42% for high germination seeds, respectively, compared to untreated samples. The results indicate that either CAP or PEMF pre-sowing treatments could be used as alternative ameliorative tools in order to improve maize growth, productivity, yield and quality of the final products

A comparative study on the effect of nonthermal processing using cold atmospheric plasma (CAP), ozonation (OZ), pulsed electromagnetic fields (PEMF) and high pressure (HP) on the quality and shelf life of fresh sea bream fillets was conducted. The aim was the selection of the optimum nonthermal processing technology for minimum effect on the fish quality and maximum shelf-life extension, based on pre-selected processing conditions for each technology. Air plasma was generated using a surface dielectric barrier discharge (SDBD) source (3 kV, 45 kHz) applied for 15 min at 25 °C. PEMF (80 J/pulsed energy, 12.5 mT, 3 Hz) and OZ (1.3 mM of aqueous ozone, flow rate 640 ppm) were also applied for 15 min at 25 °C. HP treatment at 300 MPa/5 min at 25 °C was studied. Processed and unprocessed fillets were stored at 4 °C for 22 days. The fish fillets were analysed for their microbial load, pH, texture, colour, lipid oxidation, and sensorial characteristics, during storage. The shelf life of the product was extended by 4 and 2.5 days after HP and CAP processing, respectively. HP was more effective on the microbial load reduction compared to the other processes; nevertheless, colour and texture alteration of the fish fillets was observed. CAP processing decreased the initial total microbial load by 1.03 logCFU/g, while also resulted to reduced intension of the fish odour. PEMF and OZ affected slightly the quality indices nevertheless found to be less effective on the microbial load reduction with only 1 day shelf-life extension of the fillets.

We studied the epoxy polymer surface modification using air plasma treatment in a Gliding Arc (GA) plasma reactor and a pulsed Dielectric Barrier Discharge (DBD). We employed optical emission spectroscopy (OES) measurements to approximate the vibrational and rotational temperatures for both plasma sources, as well as surface temperature measurements with fiber optics and IR thermography to corelate with the corresponding hydrophilization of the epoxy material. Water contact angle measurements revealed a rapid hydrophilization for both plasma sources, with a slightly more pronounced effect for the air DBD treatment. Ageing studies revealed stable hydrophilicity, with water contact angle saturating at values lower than 50°, corresponding to a >50% decrease compared to the untreated epoxy polymer. ATR-FTIR spectroscopy studies showed an additional absorption band assigned to carbonyl group, with its peak intensity being higher for the DBD treated surfaces. The spectra were also correlated with the surface functionalization via the relative peak area ratio of carbonyl to oxirane and benzene related bands. According to SEM imaging, GA plasma treatment led to no apparent morphological change, contrary to DBD treatment, which resulted in nano-roughness formation. The enhanced surface oxidation as well as the nano-roughness formation on epoxy surface with the air DBD treatment were found to be responsible for the stable hydrophilization.

Nanostructured surfaces usually exhibit complicated morphologies that cannot be described in terms of Euclidean geometry. Simultaneously, they do not constitute fully random noise fields to be characterized by simple stochastics and probability theory. In most cases, nanomorphologies consist of complicated mixtures of order and randomness, which should be described quantitatively if one aims to control their fabrication and properties. In this work, inspired by recent developments in complexity theory, we propose a method to measure nanomorphology complexity that is based on the deviation from the average symmetry of surfaces. We present the methodology for its calculation and the validation of its performance, using a series of synthetic surfaces where the proposed complexity measure obtains a maximum value at the most heterogeneous morphologies between the fully ordered and fully random cases. Additionally, we measure the complexity of experimental micro and nanostructured surfaces (polymeric and metallic), and demonstrate the usefulness of the proposed method in quantifying the impact of processing conditions on their morphologies. Finally, we hint on the relationship between the complexity measure and the functional properties of surfaces., Comment: 13 pages, 13 figures. Materials Today: Proceedings, 2021

In this work, we present a sound mathematical result that may correct the pixelization bias in the calculation of the line edge roughness (LER) even when the pixel size of SEM images is much larger than its rms value. This result can be useful in the LER metrology of current and future lithographic patterns where the desired rms value of LER is in the deep sub-nm range and smaller than the used pixel sizes. We computationally justify the predictions of the mathematical result and then demonstrate its application in synthesized SEM images where we can separate the impact of noise and focus on the pixelization effects in LER measurements. Furthermore, this result emphasizes the power of mathematical and computational methods to enhance the metrological output of SEM images in deep nanometer scale.

We propose a new route for pattern formation based on atmospheric pressure plasma directed assembly during photoresist removal. Atmospheric plasma etching of AZ5214E resist coated on Silicon leads to the formation of periodic, oxygen-plasma resistant residuals on the underlying substrate. The O2 content in the He/O2 gas feed was found to play significant role on the size and density of the formed structures. Fourier analysis of the spatial morphology of surfaces confirmed quantitatively the approximate periodicity and its dependence on O2 content. XPS analysis revealed the formation of sulfur-containing compounds coming from DNQ molecules of AZ5214E, which organize to etching-resistant molecules due to the synergistic effect of etching and radiation from the radio frequency (RF) discharge. Finally, we applied anisotropic plasma etching based on a pulsed-gas alternating plasma process in low pressure to transfer the atmospheric plasma induced pattern on the underlying Silicon substrate fabricating quasi-ordered Si pillars. The results show the potential of atmospheric plasma directed assembly for uniform, large-area and open-air pattern definition for application in modern nanofabrication. Keywords: Atmospheric plasma etching, Self-assembly, Plasma directed assembly, Photoresist removal, Pattern formation, Nanofabrication

In this paper, we focus on the across-edges pixelization effects on LER measurement accuracy. The pixelization across edges rounds the detected edge position according to pixel size and is expected to impact the accuracy of LER measurements (rms, correlation length, PSD curve). Given the similar size of targeted LER values in IRDS and of the pixel size used in SEM measurements, these effects are expected to gain an increasing interest and therefore to be worth studying. Our investigation is utilized with the aid of synthesized images (characterized by complete control of roughness and image parameters), with the final aim being the exploration of the link between the selected pixel size of the SEM image and the observed deviation of the measured rms (rms_m) from the true rms value (rms_t). More specifically, the goal is to find the role of the ratio of pixel size to rms_t in the measurement of rms and how we can predict it.

As the clean water shortage becomes a serious problem for mankind, atmospheric water harvesting has emerged as a viable solution. Two main approaches to collect water from the atmosphere exist: the first is to capture it from fog, whereas the second is through condensation of vapor on surfaces with a temperature below the dew point. The water collection mechanism in these two modes is completely different. In this work, we develop a deeper understanding of the effect of surface wettability on gravity-assisted atmospheric water harvesting and a comparative study of the two collection modes (fog and dew). First, we present theoretical estimates for the maximum water mass available in each mode and introduce an efficiency factor η which enables the direct comparison among surfaces in different setups and modes. Then we fabricate a series of micronanostructured surfaces with different surface wetting properties from hydrophilic to superhydrophobic. Our results demonstrate that drop mobility, derived from the surface superhydrophobic properties and micronanotopography, is the most important factor affecting fog collection: superhydrophobic surfaces show 40-65% higher fog collection rates compared to flat hydrophilic surfaces, with the more mobile among superhydrophobic surfaces (hysteresis 2°, and air-liquid fraction fA-L > 0.9) showing higher water collection. On the other hand, dew harvesting efficiency depends on the combination of drop mobility and nucleation rate, with superhydrophobic surfaces exhibiting 40% higher water collection rate compared to the flat hydrophilic or hydrophobic surfaces due to their low hysteresis as well as high surface area available for nucleation.

Hierarchical micro-nanostructured surfaces are key components of ‘smart’ multifunctional materials, used to control wetting, adhesion, tactile, friction, optical, antifogging, antibacterial, and many more surface properties. Hierarchical surfaces comprise random or ordered structures ranked by their length scale spanning the range from a few nanometers to a few micrometers, with the larger microstructures typically embedding smaller nanostructures. Despite the importance of hierarchical surfaces, there have been few studies on their precise and controlled fabrication or their quantitative characterization, and they usually involve multiple and complex fabrication steps. Here, we present a new plasma nanotechnology, which we term ‘nanoinhibit’, and a new plasma reactor for producing in one facile process-step-controlled hierarchy at will on polymeric surfaces. We couple the new plasma nanotechnology with detailed computational nanometrology based on the analysis of scanning electron microscopy images and targeted to specific functionality. We showcase the potential of ‘nanoinhibit’ for functional surface fabrication by controlling the wetting and optical functionality of the fabricated hierarchical surfaces and showing its dependence on surface morphology metrics. Finally, we observe that ‘nanoinhibit’ produces a new class of ‘strong hierarchical’ surfaces exhibiting spatially separated periodic and fractal-like components.

Cold Atmospheric Plasma is a non-thermal processing technology with great potential for application to food products as it can effectively reduce the microbial load, leading to substantial shelf-life extension. Herein, we present an easy-to-build and cost-effective Surface Dielectric Barrier Discharge (SDBD) plasma source adjusted to the plastic lid of a common commercial food container made of transparent glass. Implementation and evaluation of plasma treatment in real perishable food products such as sea bream fillets, fresh-cut rocket salads and fresh whole strawberries showed that such device might be efficiently used in-storage for the extension of their shelf-life.•Easy-to-build and cost-effective SDBD plasma source adjusted in a food container for generation of antimicrobial RONS in proximity to treated food product•Treatment of perishable food products by reducing their initial microbial load•In-storage treatment efficient for perishable food products shelf-life extension, Graphical abstract Image, graphical abstract

Conventional biomedical research models are confined to static cell culture models and animal testing, both of them representing suboptimal preclinical models. Organs-on-chips (OOCs) are novel 3D microfluidic cell culture devices lined with living cells that allow for faithful mimicry of the physiology and function of a vital human organ unit. Bone marrow-on-a-chip (BMoC) systems are currently limited to in vitro maintenance of the hematopoietic potential, supported with 3D scaffold matrices. Herein, we introduce a purely in vitro and scaffold-free bone marrow-on-a-chip device, intended for both the generation and sustainment of the perivascular hematopoietic niche, to serve as a study platform for the chronic autoimmune disease of systemic lupus erythematosus (SLE). The device consists of three layers of poly(dimethylsiloxane) (PDMS), including two cylindrical microchambers separated by an intervening porous membrane, altogether bonded to a glass slide. In this communication, the fabrication steps for a reliable and reproducible BMoC device are presented, from its design to its final assembly. As a first step towards the full recapitulation of the perivascular niche on-chip, the bone marrow stromal niche was replicated inside sealed type I collagen-coated microchambers hosting the in vitro 3D microfluidic culture of mesenchymal stem cells (MSCs) for 8 days. Culture of the MSCs revealed significant cell proliferation and progressive formation of 3D stromal tissue, a promising outcome for the subsequent 3D stromal matrix growth on the bone marrow-on-a-chip platform.

We present a disposable polymeric microfluidic device capable of reversibly binding and purifying Salmonella DNA through solid phase extraction (SPE). The microfluidic channels are first oxygen plasma treated and simultaneously micro-nanotextured, and then functionalized with amine groups via modification with L-histidine or poly-L-histidine. L-Histidine and poly-L-histidine bind on the plasma treated chip surface, and are not detached when rinsing with DNA purification protocol buffers. A pH-dependent protocol is applied on-chip to purify Salmonella DNA, which is first bound on the protonated amines at a pH (5.0) lower than their pKa of surface amine-groups which is 6.0 and then released at a pH higher than the pKa value (10.5). It was found that modification with poly-L-histidine resulted in higher surface density of amine groups onto microfluidic channel. Using the chip modified with poly-L-histidine, high recovery efficiency of at least 550 ng of isolated Salmonella DNA as well as DNA purification from Salmonella cell lysates corresponding to less than 5000 cells or 0.026 ng of Salmonella DNA was achieved. The protocol developed does not require ethanol or chaotropic solutions typically used in DNA purification, which are known inhibitors for downstream operations such as polymerase chain reactions (PCR) and which can also attack some polymeric microfluidic materials. Therefore, the microfluidic device and the related protocol hold promise for facile incorporation in microfluidics and Lab-on-a-chip (LOC) platforms for pathogen detection or in general for DNA purification.

We propose a methodology for the mathematical and quantitative characterization of the deviation of rough line/space patterns from their ideal smooth shape to identify defects related to line mass and shape. The methodology is applied in real AFM images of line/space patterns while a modelling framework is elaborated for the generation of rough line/space patterns with controlled top and sidewall roughness and size variations. We also explore the consequences of the proposed methodology in the metrology of LER and its relation to 3D patterns.

Bacterial attachment and colonization to hygiene sensitive surfaces, both public and nosocomial, as well as in food industry areas, poses a serious problem to human healthcare. Several infection incidents are reported, while bacterial resistance to antibiotics is increasing. Recently, novel techniques for the design of antibacterial surfaces to limit bacterial spreading have emerged, including bifunctional antibacterial surfaces with antifouling and bactericidal action. In this context, we have recently developed smart, universal, metal-sputtered superhydrophobic surfaces, demonstrating both bacterial repulsion and killing efficacy. Herein, we present the optimization process that led to the realization of these &ldquo, hybrid&rdquo, antibacterial surfaces. To this end, two bactericidal agents, silver and copper, were tested for their efficiency against Gram-negative bacteria, with copper showing a stronger bactericidal action. In addition, between two low surface energy coatings, the fluorinated-alkyl self-assembled chlorosilane layer from perfluorinated octyltrichlorosilane (pFOTS) solution and the fluorocarbon layer from octafluorocyclobutane (C4F8) plasma were both approved for their anti-adhesive properties after immersion in bacterial solution. However, the latter was found to be more efficient when engrafted with the bactericidal agent in shielding its killing performance. Furthermore, the thickness of the plasma-deposited fluorocarbon layer was optimized, in order to simultaneously retain both the superhydrophobicity of the surface and its long-term bactericidal activity.

Atmospheric Pressure Plasmas (APPs) are promising alternatives to their low-pressure counterparts for material surface treatment due to their potential for cost-effective continuous processing. Here we present for the first time to our knowledge a palette of applications of polymer etching showing the potential of APPs for cleaning/ashing, nanopattern formation, nanotexturing, and hierarchical superhydrophobic surface fabrication using the same plasma source configuration. First, we used a dielectric barrier discharge (DBD) plasma source to study etching/cleaning/ashing of different polymers such as PMMA films and AZ photoresist with lithographic patterns using He/O2 mixtures. We achieved high-rate, uniform etching, indicating the source potential for cleaning/ashing even in ambient air conditions. We have noticed that thick photoresist films are damaged after prolonged etching in air plasmas, a phenomenon resembling photoresist damage observed during low-pressure plasma etching. Second, we applied colloidal lithography with polystyrene (PS) nanoparticles followed by isotropic APP etching in order to form nanopatterns on both Silicon and Polymers. We observed that APP induces “cauliflower-like” nanotexturing of the PS spheres. This nanotexturing in combination with plasma etching of the underlying polymer and the spheres allow the fabrication of hierarchical surfaces. Optimization of plasma etching duration (i.e. hierarchical topography) followed by low-pressure plasma deposition of a low surface energy fluorocarbon (hydrophobic) coating led to the preparation of superhydrophobic surfaces with water contact angle 158° and hysteresis 9° (roll-off behavior).

Hydrophobic surfaces are often used to reduce wetting of surfaces by water. In particular, superhydrophobic surfaces are highly desired for several applications due to their exceptional properties such as self-cleaning, anti-icing, anti-friction and others. Such surfaces can be prepared via numerous methods including plasma technology, a dry technique with low environmental impact. Atmospheric pressure plasma (APP) has recently attracted significant attention as lower-cost alternative to low-pressure plasmas, and as a candidate for continuous rather than batch processing. Although there are many reviews on water-repellent surfaces, and a few reviews on APP technology, there are hardly any review works on APP processing for hydrophobic and superhydrohobic surface fabrication, a topic of high importance in nanotechnology and interface science. Herein, we critically review the advances on hydrophobic and superhydrophobic surface fabrication using APP technology, trying also to give some perspectives in the field. After a short introduction to superhydrophobicity of nanostructured surfaces and to APPs we focus this review on three different aspects: (1) The atmospheric plasma reactor technology used for fabrication of (super)hydrophobic surfaces. (2) The APP process for hydrophobic surface preparation. The hydrophobic surface preparation processes are categorized methodologically as: a) activation, b) grafting, c) polymerization, d) roughening and hydrophobization. Each category includes subcategories related to different precursors used. (3) One of the most important sections of this review concerns superhydrophobic surfaces fabricated using APP. These are methodologically characterized as follows: a) single step processes where micro-nano textured topography and low surface energy coating are created at the same time, or b) multiple step processes, where these steps occur sequentially in or out of the plasma. We end the review with some perspectives in the field. We aspire to address scientists, who will get involved in the fields of (super)hydrophobicity and/or in atmospheric pressure plasma processing.

Collapse (Cassie to Wenzel) wetting transitions impede the electrostatically induced reversible modification of wettability on superhydrophobic surfaces, unless a strong external actuation (e.g., substrate heating) is applied. Here we show that collapse transitions can be prevented (the droplet remains suspended on the solid roughness protrusions) when the electrostatic force, responsible for the wetting modification, is smoothly distributed along the droplet surface. The above argument is initially established theoretically and then verified experimentally.

Plasma treatment is an environmentally friendly solution for modifying or nanostructuring the surface of several materials including photoactive polymers. The detailed characterization of the effect of plasma treatment on chemical and optoelectronic properties of photoactive polymers is, therefore, of specific interest. Herein, the effect of the exposure of poly(3-hexylthiophene) (P3HT) thin films to plasma created in three different gases (oxygen, argon and hydrogen) was studied. A range of spectroscopic techniques, such as x-ray (XPS) and ultraviolet (UPS) photoelectron spectroscopy in conjunction with UV–vis absorption, Fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopies, are employed to quantify the extent of chemical modification occurring in each particular case. It is shown that oxygen plasma treatment leads to the disruption of the π-conjugation via the direct oxidation of the sulfur atom of the thiophene ring while the aliphatic side chain remains nearly unaffected. An oxidation mechanism is proposed according to which the sulfur atom of the thiophene ring is oxidized into sulfoxides and sulfones, which subsequently degraded into sulfonates or sulfonic acids in a relatively small degree. For argon and hydrogen plasma treatments some oxidation products are detected only at the polymer surface. In all cases the polymer surface Fermi level is shifted closer to the highest occupied molecular orbital (HOMO) energy after plasma treatment indicating p-type doping arising from surface oxidation.

Materials of relevance in Printed circuit board (PCB) technology such as FR4, polyimides, and imide-based photosensitive dry films are being currently implemented for the fabrication of microfluidic devices integrated on PCB with electric circuitry and sensors. In this work, methods for efficient and stable in time hydrophilization of these substrates were developed to promote microchannel filling and prevent protein or other biomolecule adsorption. Well-established and easy to implement methods such as plasma etching and PEG coatings were explored. The wettability of the modified surfaces was probed as a function of time after surface hydrophilization by means of water contact angle measurements, while assessment of protein adsorption was implemented as a means to investigate the presence of protein-repellent PEG coatings. Surface superhydrophilization with extreme stability over time at room and elevated temperatures was demonstrated on plasma micro nanotextured polyimide surfaces, retained for up to 80 days. FR4 and photosensitive imide-based dry film surfaces were hydrophilized with stable in time PEG-silane coatings, also retaining their hydrophilicity at elevated temperatures. Furthermore, they were most successfully (super)hydrophilized with UV-assisted PEG coatings, also proven stable in time and at elevated temperatures. Finally, capillary pumping was demonstrated on open microchannels created on FR4 with optimal coatings.

Wetting control is essential for many applications, such as self-cleaning, anti-icing, anti-fogging, antibacterial action as well as anti-reflection and friction control. While significant effort has been devoted to fabricate superhydrophobic/superamphiphobic surfaces (repellent to water and other low surface tension liquids), very few polymeric superhydrophobic/superamphiphobic surfaces can be considered as durable against various externally imposed stresses (e.g. application of heating, pressure, mechanical forces, chemical, etc.). Therefore, durability tests are extremely important for applications especially when such surfaces are made of "soft" materials. Here, we review the most recent and promising efforts reported towards the realization of durable, superhydrophobic/superamphiphobic, polymeric surfaces emphasizing the durability tests performed, and some important applications. We compare and put in context the scattered durability tests reported in the literature, and present conclusions, perspectives and challenges in the field.

A microfluidic platform optimized for bead-based immunoassays is presented. It uses a simple design that incorporates passive valves in the inlet and outlet of a microreactor. The superhydrophobic, passive valves are created by selective plasma nanotexturing and deposition of a hydrophobic layer. The anti-sticking operation of the valves simplify the working principle, reduce the reagents needed, and enhance the fluorescence intensity of the assays performed on chip by reducing non-specific binding compared to assays performed on plate. Two different multi-step immunoassays were tested individually and as a mixture to evaluate the platform performance: IL6 and PDGF-2 human protein assays. The results show that the proposed platform offers faster assay kinetics, allows lower reagent use (5l instead of 50), enhanced fluorescent signals (by a factor of two or more), and reduced incubation time at least by a factor of 2. A possible configuration using the microfluidic platform for a portable biosensing system is also demonstrated. Display Omitted Superhydrophobic valves are incorporated inside a microfluidic.IL6 & PDGF-2 human proteins are detected using an antifouling LOC device.Time of analysis and sensitivity are improved using the LOC device.A portable biosensing system is demonstrated.

A photovoltaic device based on plasma-etched silicon nanopillar (SiNP) arrays is demonstrated. Highly ordered, aligned and perpendicular to the substrate pure crystalline silicon nanopillars, that follow the axial p-n junction geometry, are fabricated by polystyrene colloidal particle self-assembly followed by cryogenic silicon plasma etching. The SiNPs surface electrical passivation by both methyl termination and hydrogen termination is examined and the encapsulation of the pillars by PMMA and transparent conductive oxide is demonstrated. The total reflectance (both specular and diffuse) of SiNP arrays of different period and diameter is measured. The total reflectance of silicon is reduced significantly in a wide range of the optical spectrum. Electrical characterization of bundles of nanowires was performed in terms of I-V measurements under light illumination. A short-circuit current density (Jsc) of 18.9mA/cm2, an open-circuit voltage (Voc) of 367mV and a fill factor (FF) of 0.59 were obtained on such axial p-n SiNP array photovoltaic devices. Display Omitted Si nanopillar fabrication by cryogenic plasma etching after colloidal lithographyAxial p-n junction Si nanopillar photovoltaic device fabricationStudy of electrical passivation, and demonstration of low reflectance.A fill factor of 0.59 was investigated for axial Si pillar PV device.Promising performance of the proposed recipe to fabricate next generation PV cells

The aim of this work is to clarify the quantitative relationship between the Edge Placement Error (EPE) and Line Edge Roughness (LER) in a rough pattern. Using a computational modelling approach to isolate this relationship, we show that despite the dominant role of Rms(LER), EPE is also affected by the correlation length especially at long length of interests. Similarly, we demonstrate and quantify the positive correlation of the edge correlation coefficient with Image Placement Error. The ultimate concern is to get design-rule determinations based on EPE definitions and characterization which is informed by modern manufacturing and metrology aspects of LER.