Thin Cells Research Articles

Optimization of in vitro regeneration of Ferocactus peninsulae (Barrel Cactus) through transverse thin cell layer (tTCL) culture: a strategy for large-scale propagation

Optimization of in vitro regeneration of Ferocactus peninsulae (Barrel Cactus) through transverse thin cell layer (tTCL) culture: a strategy for large-scale propagation

Endogenous hormone alteration during callus and adventitious root formation through thin cell layer culture system in Phyllanthus amarus

Endogenous hormone alteration during callus and adventitious root formation through thin cell layer culture system in Phyllanthus amarus

Surface Modification of Heterojunction with Intrinsic Thin Layer Solar Cell Electrode with Organosilane

Solar cell (SC) technologies, which are essential in the transition toward sustainable energy, utilize photovoltaic cells to convert solar energy into electricity. Of the available technologies, heterojunction with intrinsic thin-layer (HIT) solar cells offers high efficiency and reliability. The current study explored the enhancement of HIT solar cell performance through the use of 3-aminopropyltrimethoxysilane (APTMS) self-assembled monolayers (SAMs) on the surface of the cells’ indium tin oxide (ITO) layer. Photoluminescence mapping revealed greater brightness and photocurrent in the HIT sample treated with APTMS SAMs, with the results indicating more favorable optical and electrical properties. The application of APTMS SAMs led to higher open-circuit voltage, fill factor, maximum power output, and efficiency by passivating the ITO surface and achieving energy level alignment, thereby enhancing the charge carrier dynamics. These findings demonstrate the potential of APTMS SAMs to improve HIT solar cell efficiency and reliability.

Ionic Liquid-Assisted Strategy for Morphology Engineering of Inorganic Cesium-Based Perovskite Thin Films Toward High-Performance Solar Cells.

The wide bandgap CsPbI2Br perovskite materials have attracted significant attention due to their high thermal stability and compatibility with narrow bandgap materials in tandem devices. The performance of perovskite solar cells (PSCs) is highly dependent on the quality of the perovskite layer, which is governed by the crystallization process during solution processing. However, the crystallization dynamics of CsPbI2Br thin films remain less explored compared to conventional organic-inorganic perovskites. Achieving high-quality CsPbI2Br films with uniform morphology and large perovskite grains remains challenging with standard solution techniques. This study applies the ionic liquid (IL) [EMIM]+[PF6]- as an additive within the bulk CsPbI2Br absorber layer. Within our experimental regime, [EMIM]+[PF6]- accelerates the crystallization process while promoting the formation of large perovskite grains, a feature not commonly observed in previous studies. Our experimental results suggest that the IL acts as heterogeneous nucleation sites, and varying IL incorporation amount significantly impacts the morphology of CsPbI2Br perovskite films. Consistent UV-vis and photoluminescence (PL) red-shifts are observed in the IL-incorporated CsPbI2Br films, with X-ray diffraction (XRD) data projecting an influence on the perovskite crystal structure. These findings provide new insights into the role of ILs in controlling crystallization and morphology that have been minimally discussed in the literature. The incorporation of an optimized amount of [EMIM]+[PF6]- promotes the formation of highly crystalline perovskite thin films with excellent morphology, reducing defect density, enhancing carrier transport, and yielding large grain sizes. As a result, PSCs fabricated with [EMIM]+[PF6]- achieved a power conversion efficiency (PCE) of 17.11% (stabilized at 15.87%) and an open-circuit voltage (VOC) of 1.39 V, along with improved stability compared to control devices. This work provides a straightforward approach for producing high-quality CsPbI2Br thin films with high reproducibility, contributing valuable advancements to Cs-based PSCs.

Solution‐Processed Multifunctional Thin‐Film Encapsulation of Perovskite Thin Films and Devices

Herein, the effect of multicomponent composite encapsulation on the stability of perovskite thin films and perovskite solar cells, as well as lead leakage upon water immersion, is investigated. The encapsulation is simple and low cost since it is entirely deposited by solution processed techniques in the ambient atmosphere. It consists of a spray‐coated composite layer sandwiched between two spin‐coated layers. The composite layer contains hygroscopic nanomaterials, oxygen scavengers, and lead adsorbing nanomaterials, which enables reduced lead leakage and improved stability of encapsulated perovskite during storage in ambient, immersion in water, as well as illumination in dry air. The encapsulation layers show high transmittance and did not have a significant effect on the short‐circuit current density and open‐circuit voltage despite the deposition of encapsulation in ambient air. The encapsulated devices retain 80% of their initial performance after 4 h of immersion in water.

Selenium‐Rich Sb2(S,Se)3 Thin Films Deposited via Sequential Chemical Bath Deposition for High‐Efficiency Solar Cells

AbstractRecently, solution‐processed antimony sulfoselenide (Sb2(S,Se)3) thin films and solar cells have gained popularity and achieved impressive results. One of the most effective improvements is the chemical bath deposition (CBD) approach, which is gentle, highly adjustable, and scalable. However, development in alloyed Sb2(S,Se)3 using this process has been modest, with a power conversion efficiency (PCE) of roughly 8%. In this work, a sequential CBD deposition strategy is designed, introducing sulfur (S) or selenium (Se) sources at different stages of the CBD process to achieve high‐quality Sb2(S,Se)3 thin films and devices. Impressively, adding a moderate amount of sodium thiosulfate and thioacetamide as mixed sulfur sources during the CBD deposition of Sb2Se3 can produce Se‐rich Sb2(S,Se)3 films with high crystallinity, suitable bandgaps, low defect density, and favorable energy level alignment. With a short‐circuit current density (JSC) of 26.80 mA cm−2 and a fill factor (FF) of 65.89%, the solar cells with the FTO/CdS/Sb2(S,Se)3/Spiro‐OMeTAD/Au structure obtained an impressive PCE of 9.29%, the highest to date for Sb2(S,Se)3 solar cells manufactured with the CBD process. This study provides a feasible approach for enhancing the performance of CBD‐produced Sb2(S,Se)3 solar cells and offers new insights and techniques for the synthesis of other complex multicomponent thin films.

A preliminary investigation of banana pseudo-stem (Musa cavendish) for pulp and paper production: morphology, chemical composition, FTIR, XRD and thermogravimetric analysis

Abstract In today’s world, the use of paper and cardboard increasing but the availability of raw materials and the environmental impact on the paper industry is a big concern. To address these concerns, researchers are exploring the potential of agricultural waste products as raw materials for pulp production. This study uses morphological, chemical composition, FTIR, XRD, and thermogravimetric analysis to examine the potential of banana pseudo-stem as a raw material for paper pulp to address environmental concerns and raw material shortages in the paper industry. The study reveals favorable characteristics for papermaking, including long fiber length (1750 μm), thin cell wall thickness (9.7 μm), and large lumen diameter (22.15 μm). The chemical composition of banana pseudo-stem contains cellulose (44.93 %), hemicellulose (23.7 %), and Klason lignin (11.1) showing its suitability for pulp production. FTIR analysis highlights the functional groups present on the banana pseudo-stem. The XRD analysis shows that it has a similar cellulosic peak and crystallinity index with common raw materials used in pulp production. The thermogravimetric analysis shows that the banana pseudo-stem has high thermal stability. The findings demonstrate that banana pseudo-stem, both by itself and in combination with other raw materials, might be a potential raw material for the pulp production.

Structural, electronic, and optical-absorption properties of 2D Si thin films

AbstractRecent experimental studies highlighted the potential of thin-film crystalline silicon (Si) for high-efficiency solar cells. Using density functional theory, we investigated 2D Si thin films across various orientations, thicknesses, and surface structures to elucidate their structure–property relationships. Through surface-energy calculations and Wulff construction, we determined the crystal habit of Si, which aligns with available experimental observations. Electronic-structure calculations underscored the critical role of valence saturation on surfaces in enabling semiconducting behavior in Si thin films, essential for optical applications. From optical-absorption calculations, we identified the surface index exhibiting the highest absorption coefficients for thin films Si solar cell applications. Graphical abstract

Precision in situ cryogenic correlative light and electron microscopy of optogenetically positioned organelles.

Unambiguous targeting of cellular structures for in situ cryo-electron microscopy in the heterogeneous, dense and compacted environment of the cytoplasm remains challenging. Here, we have developed a cryogenic correlative light and electron microscopy (cryo-CLEM) workflow that utilizes thin cells grown on a mechanically defined substratum for rapid analysis of organelles and macromolecular complexes by cryo-electron tomography (cryo-ET). We coupled these advancements with optogenetics to redistribute perinuclear-localised organelles to the cell periphery, allowing visualisation of organelles that would otherwise be positioned in cellular regions too thick for cryo-ET. This reliable and robust workflow allows for fast in situ analyses without the requirement for cryo-focused ion beam milling. Using this protocol, cells can be frozen, imaged by cryo-fluorescence microscopy and be ready for batch cryo-ET within a day.

Twist disclinations mediated transformations in confined nematic liquid crystals

We studied numerically structural transformations in different confined nematic liquid crystals (LC) mediated by chargeless (twist) disclinations. Firstly, we focus on the role of twist disclinations in Moiré-type geometrical setup where LC is confined in a plane-parallel cell. We impose an azimuthal rotation to initially parallel wedge disclinations where the total topological charge of the system equals to zero. Two qualitatively different scenarii are observed depending on the cell thickness. In thin enough cells the disclinations touch in the mid-plane which enables continuous transformation into a final structure consisting of two twist disclinations confined to the limiting substrates. On the other hand, in thinner cells an additional chargeless loop is formed in the mid-plane. In this case, on rotating the initially parallel disclinations periodic structural reentrant behavior is observed. In cylindrical geometry we considered transformations between the initial metastable escaped radial structure with point defects (ERPD) into escaped radial (ER) or planar polar structure with line defects (PPLD). In both cases two nearby ring-like point defects within the ERPD structure collide and temporarily form a chargeless twist disclination loop. The latter in the ERPD-ER transformation shrinks and enables continuous transformation into the final thermodynamically stable structure. On the contrary, in the ERPD-PPLD transformation the twist loop, whose local structure matches PPLD configuration, increases and converts the system continuously into the global PPLD configuration. Detailed understanding of chargeless defect mediated transformations is beneficial for development of future switching devices based on continuous nematic structural transformations between LC structures exhibiting significantly different optical features.

Enhanced Antireflection and Absorption in Thin Film GaAs Solar Cells Using Dielectric Composite Nanostructures

This study investigates the application of dielectric composite nanostructures (DCNs) to enhance both antireflection and absorption properties in thin film GaAs solar cells, which are crucial for reducing production costs and improving energy conversion efficiency in photovoltaic devices. Building upon previous experimental validations, this work systematically explores the underlying theoretical mechanisms using the finite difference time domain (FDTD) method to analyze the light interaction with the proposed DCNs. The results show that the combination of Mie resonance, Fabry–Perot resonance, and guided resonance, induced by the surface structuring of the DCNs, significantly enhances light absorption in the active layer, particularly at longer wavelengths. For solar cells featuring a 500-nm-thick absorber layer, SARL-decorated solar cells demonstrated an average reflectivity of 12.18%, whereas those incorporating DCNs exhibited a significantly reduced average reflectivity of 4.52%. These findings indicate that DCNs structures are highly effective in enhancing the performance of thin and ultra-thin GaAs solar cells by minimizing surface reflection and increasing photon utilization, offering a promising solution for high efficiency, cost effective photovoltaic devices.

Effect of surface alignment on electric-field-induced phase transitions in blue phases

This study investigates the critical electric field thresholds required for phase transitions in the blue phases of liquid crystals (BPs) confined within vertical field switching cells. BPs are attractive for electro-optical applications due to their polarization-independent response and fast switching times; however; challenges remain regarding their limited temperature stability and previously reported high operational voltages. We employ a combined approach of polarized optical microscopy and electrical impedance analysis to identify the electric field thresholds triggering BP transitions to focal conic domains in cells with and without planar polyimide alignment layers. We show that surface alignment layers stabilize the blue phases and allow for higher applied electric fields before transitioning into the focal conic state. This suggests the possibility of a wider operational voltage range in thinner cells with alignment layers. These findings significantly improve our understanding of BPs, addressing key challenges and paving the way for their integration into advanced photonic devices, based on the CMOS technology.

Surface treatment processed electron transport layers for efficient Sb2S3 solar cells

Solution-processed Sb2S3 thin films and solar cell devices have recently gained popularity due to their easy procedure and outstanding final device performance. Nevertheless, although the substrate has a significant influence on thefollowing functional films, the effect of the substrate in the Sb-based solar cells appears to have not been adequately examined. In this study, we performed an interesting thioacetamide (TA)-assisted surface treatment strategy on the electron transport layer (ETL) to achieve high-quality development of Sb2S3 thin films and based solar devices. The surface treatment of ETLs resulted in a uniform surface, Zn(OH)2 impurity reduction, and excellent wettability. The above enhanced the growth of Sb2S3 thin films with features like extremely large crystal sizes (∼8 um), more homogeneous and dense film morphology, preferred crystal orientation, reduced oxygen content, and fewer defects, which benefits carrier transport. Finally, a device structure constructed of FTO/TiO2/Zn(O,S)/Sb2S3/Spiro/Au was created, resulting in an almost 30 % increase in efficiency, from 4.05 % to 5.21 %. The proposed approach not only gives new insights into generating higher-quality Sb2S3 thin films and devices, but it also presents new concepts and methods for future high-quality sulfide thin film preparation.

Design perspectives of a thin film GaAs solar cell integrated with Carrier Selective contacts and anti-reflection coatings: Optical and device analysis

III-V thin-film solar cells (SCs) have shown exceptional optoelectronic properties and remarkable power conversion efficiency (PCE), attributed to their outstanding charge transport, efficient photon trapping, adaptability, and recycling of photons. In particular, incorporating anti-reflective coatings (ARCs) made from wide-bandgap oxides has proven effective in reducing optical losses, with reductions as low as 20 % being reported. Furthermore, the use of carrier-selective contacts in these designs not only eliminates the need for complex doped junctions but also simplifies the fabrication process, further enhancing their performance. Despite these advancements, relatively few studies have explored the integration of both ARCs and carrier-selective contacts in gallium arsenide (GaAs)-based thin-film solar cells. This gap represents a significant opportunity for improving the efficiency and performance of these devices. To address this, we present a GaAs thin-film solar cell incorporating an ARC layer for enhanced light-trapping and optimized photon absorption. In addition, we integrate carrier-selective contacts using titanium dioxide (TiO2) as the electron transport layer and molybdenum oxide (MoO3) as the hole transport layer, ensuring effective charge separation and collection. Our optical analysis demonstrates that, with an optimized ARC thickness, the optical losses in the 380 nm-thick GaAs absorber layer can be limited to 20 %. Moreover, by maintaining a surface recombination velocity (SRV) of 103 cm/s and a carrier lifetime of 10μs, the proposed design achieves an impressive PCE of approximately 23 %. This study highlights the potential of combining ARCs and carrier-selective contacts to push the performance of GaAs thin-film solar cells to new heights, paving the way for more efficient, and cost-effective photovoltaic technologies.

Zygospore formation in Zygnematophyceae predates several land plant traits.

Recent research on a special type of sexual reproduction and zygospore formation in Zygnematophyceae, the sister group of land plants, is summarized. Within this group, gamete fusion occurs by conjugation. Zygospore development in Mougeotia, Spirogyra and Zygnema is highlighted, which has recently been studied using Raman spectroscopy, allowing chemical imaging and detection of changes in starch and lipid accumulation. Three-dimensional reconstructions after serial block-face scanning electron microscopy (SBF-SEM) or focused ion beam SEM (FIB-SEM) made it possible to visualize and quantify cell wall and organelle changes during zygospore development. The zygospore walls undergo strong modifications starting from uniform thin cell walls to a multilayered structure. The mature cell wall is composed of a cellulosic endospore and exospore and a central mesospore built up by aromatic compounds. In Spirogyra, the exospore and endospore consist of thick layers of helicoidally arranged cellulose fibrils, which are otherwise only known from stone cells of land plants. While starch is degraded during maturation, providing building blocks for cell wall formation, lipid droplets accumulate and fill large parts of the ripe zygospores, similar to spores and seeds of land plants. Overall, data show similarities between streptophyte algae and embryophytes, suggesting that the genetic toolkit for many land plant traits already existed in their shared algal ancestor. This article is part of the theme issue 'The evolution of plant metabolism'.

High efficiency Sb and Ag double doped Cu2ZnSn(S, Se)4 thin film solar cells realized by post-heat treatment process of heterojunction

Cu2ZnSn (S, Se)4 (CZTSSe) semiconductors have become a recent focus of research owing to their cost-effectiveness, environmental friendliness, and high efficiency. However, insufficient band alignment between the CZTSSe absorption layer and the CdS buffer layer significantly hampers the high conversion efficiency of CZTSSe devices. In this study, problems related to energy-band matching were solved by the post-heat treatment (PHT) of the absorber and buffer layers. Based on obtaining a high-quality absorption layer through double-doped (Cu, Ag)2Zn(Sn, Sb)(S, Se)4 (CAZTSSSe), the impact of the PHT process of CAZTSSSe/CdS on the device performance and heterojunction quality was investigated. The PHT process promoted the reciprocating motion of elements in the heterojunction region, directly inducing the movement of Cd towards the absorption layer and Cu towards the buffer layer. Furthermore, the PHT method enhances the recrystallization of CdS, resulting in the formation of a CdS layer with excellent crystalline quality. After PHT processing, a more favorable conduction band arrangement was obtained, which helps to reduce non-radiative recombination. Ultimately, when the PHT temperature reaches 200 °C, we get an optimal device with an efficiency of up to 9.44 %, as open circuit voltage (VOC) escalates to 431 mV, and lower fill factor (FF) attains 55.63 %. It is believed that this PHT process can be better applied in thin film cells to obtain high-efficiency solar cells.

Multipurpose Impacts of Silver Nitrate on Direct Organogenesis of Begonia rex cv. DS-EYWA via Transverse Thin Cell Layering (tTCL) Technique

Begonia rex cv. DS-EYWA is an important plant for indoor and outdoor cultivation, and cv. DS-EYWA is a rare unique cultivar with curly, colorful leaves. Due to their importance, applying plant tissue culture techniques for mass and healthy production in a short period of time without seasonal limitation is of immense economic value. Applying several concentrations of silver nitrate (AgNO3) in combination with varied concentrations of cytokinins including 6-benzylaminopurine (BAP), thidiazuron (TDZ) (0, 0.5, 1, 1.5 mgL−1), and 1-naphthaleneacetic acid (NAA) auxin (0, 0.5, 1 mgL−1) via focusing on transverse thin cell layer (tTCL) petiole explants for high-scale production was used to establish an efficient in vitro propagation protocol. Our results showed that even low concentrations (25 mgL−1) can control internal bacterial infection and increase shoot direct regeneration efficiency. A combination of 1.5 mgL−1 BAP, 0.5 mgL−1 NAA, and 25 mgL−1 AgNO3 was the best treatment to increase the number of direct regenerated shoots, and a lower concentration of BAP (0.5 mgL−1) can be suggested for shoot elongation. Elongated shoots were successfully rooted in MS basal medium and acclimatized in a 1:1 peat moss/perlite sterilized pot mixture.

Improved performance of thermophotovoltaic energy conversion with Tamm plasmon emitters enabled by back gapped reflectors

A thermophotovoltaic (TPV) system that can convert thermal radiation from terrestrial heat sources into electricity, plays an important role in energy utilization, waste heat recovery and so on. In order to enhance the conversion efficiency of a TPV system having a narrow-band thermal emitter, we propose to add a back gapped reflector (BGR) to recover more out-of band (OOB) photons. We first design a Tamm plasmon thermal emitter to yield a narrow-band emission peak matching well with the bandgap of the InGaAs cell. Then, we add a BGR on the PV cell to regulate the absorption spectrum of the cell. Results show that, compared to the back surface reflector (BSR), the TPV system with the Au BGR cell has a higher power conversion efficiency (PCE), because more OOB photons are reflected back to the emitter by the Au BGR cell, so that the absorbed power by the cell decreases while the output power is improved. Due to the contribution of recycled OOB photons, at 1500 K, a 1.7 % OOB reflectance gain of the BGR (h = 0.2 μm, t = 1.2 μm) can actually increase the PCE by about 4 %. In addition, a thin PV cell and an appropriately thick air gap layer of 0.4–0.6 μm are suggested to obtain a high η × Pout. The PCE of the TPV system based on the Tamm plasmon emitter is higher and becomes saturated at a lower temperature than the broad-band SiC emitter. This work may facilitate high-performance TPV energy conversion.

Soft X-ray spectromicroscopy of human fibroblasts with impaired sialin function.

Salla disease (SD) is a lysosomal storage disease where free sialic acid (SA) accumulates in lysosomes due to the impaired function of a membrane protein, sialin. Synchrotron radiation-based scanning transmission soft X-ray spectromicroscopy (STXM) was used to analyze both SD patients' fibroblasts and normal human dermal fibroblasts (NHDF) from healthy controls. Both cell lines were also cultured with N-acetyl-d-mannosamine monohydrate (ManNAc) to see if it increased SA concentration in the cells. The STXM technique was chosen to simultaneously observe the morphological and chemical changes in cells. It was observed that free SA did not remain in the lysosomes during the sample processing, leaving empty vacuoles to the fibroblasts. The total cytosol and entire cell spectra, however, showed systematic differences between the SD and NHDF samples, indicating changes in the relative macromolecular concentrations of the cells. The NHDF cell lines contained a higher relative protein concentration compared to the SD cell lines, and the addition of ManNAc increased the relative protein concentration in both cell lines. In this study, two sample preparation methods were compared, resin-embedded thin sections and cells grown directly on sample analysis grids. While the samples grown on the grids exhibited clean, well-resolved spectra not masked by embedding resin, the low penetration depth of soft X-rays hindered the analysis to only the thin region of the microfilaments away from the thick nucleus.

Effect of carrier gas on copper antimony sulfide thin films by spray pyrolytic approach

This study explores the ternary compound semiconductor as a potential absorber layer for third-generation solar cells. CuSbS2, a promising candidate for thin film absorber layers, is fabricated using a simple spray pyrolysis method. The research specifically investigates the influence of two different carrier gases during the fabrication process. X-ray diffraction as well as Raman studies confirm that the films exhibit a chalcostibite structure. Notably, films fabricated with nitrogen as the carrier gas demonstrate enhanced crystallinity, accompanied by reduced microstrain and dislocation density. Furthermore, these films exhibit a significantly improved absorption coefficient, reaching 105 cm-1 . Optical studies indicate that the materials possess a direct band gap of 1.50 eV and exhibit p-type conductivity. CuSbS2 thin film heterojunction solar cell exhibits a maximum efficiency of 0.49%.