Correction: Efficient broadband light absorption in thin-film a-Si solar cell based on double sided hybrid bi-metallic nanogratings

Correction for ‘Efficient broadband light absorption in thin-film a-Si solar cell based on double sided hybrid bi-metallic nanogratings’ by Fazal E. Subhan et al., RSC Adv., 2020, 10, 11836–11842, DOI: 10.1039/C9RA10232A.

The authors regret that the name of one of the authors (Rehan Ullah Khan) was shown incorrectly in the original article. In addition, the affiliations for this author were incorrectly given. The corrected author list and affiliations are as shown above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Super absorption of solar energy using a plasmonic nanoparticle based CdTe solar cell

Improving the photon absorption in thin-film solar cells with plasmonic nanoparticles is essential for the realization of extremely efficient cells with substantial cost reduction. Here, a comprehensive study of solar energy enhancement in a cadmium telluride (CdTe) thin-film solar cell based on the simple design of a square array of plasmonic titanium nanoparticles, has been reported. The excitation of localized plasmons in the metallic nanostructures together with the antireflection coating (ARC) significantly enhances the absorption of photons in the active CdTe layer. The proposed structure attained super absorption with a mean absorbance of more than 97.27% covering a wide range from visible to near-infrared (i.e., from 300 nm to 1200 nm), presenting a 90% absorption bandwidth over 900 nm, and the peak absorption is up to 99.9%. For qualitative analysis, the photocurrent density is also estimated for AM 1.5 solar illumination (global tilt), whose value reaches 40.36 mA cm⁻², indicating the highest value reported to date. The impact of nanoparticle dimensions, various metal materials, shapes, and random arrangement of nanoparticles on optical absorption are discussed in detail. Moreover, the angle insensitivity is essentially validated by examining the absorption performance with oblique incidences and it is found that the solar cell keeps high absorption efficiency even when the incidence angle is greater than 0°. Therefore, these findings suggest that the proposed broadband structure has good prospect in attaining high power conversion efficiency while reducing the device cost.

Improving the photon absorption in thin-film solar cells with plasmonic nanoparticles is essential for the realization of extremely efficient cells with substantial cost reduction.     

Green-solvent-processed hybrid solar cells based on donor–acceptor conjugated polyelectrolyte

In this work, a quaternary ammonium side chain modified conjugated polyelectrolyte PFBTBr, with excellent solubility in nonaromatic and nonhalogenated solvents, was designed and synthesized as the donor material for the green-solvent-processed hybrid solar cells (HSCs). By introducing the donor–acceptor structure, PFBTBr shows a lower lying highest occupied molecular orbital (HOMO) level and a broad absorption from 300 to 700 nm. Incorporating the water soluble CdTe nanocrystals (NCs) as acceptor, the green-solvent-processed HSCs based on conjugated polyelectrolyte and inorganic NCs were fabricated. Through the active layer optimization, a well blended donor/acceptor active layer with continuous electron/hole transport pathway and smoother surface was achieved. As a result, a photovoltaic efficiency of 3.67% was realized. After the further interfacial modification and chloride treatment, the power conversion efficiency of the green-solvent-processed HSCs was improved to 5.03% with the maximum external quantum efficiency value of 87.01% at 400 nm under the AM 1.5 G 100 mW cm⁻² illumination.

In this work we synthesized a donor–acceptor conjugated polyelectrolyte as a donor for green-solvent-processed hybrid solar cells with a PCE of 5.03%.     

Efficient and chromaticity-stable flexible white organic light-emitting devices based on organic–inorganic hybrid color-conversion electrodes

We have developed a novel organic–inorganic hybrid color conversion electrode composed of Ag NWs/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) via a solution process, which is the first report on a color conversion electrode for applications in flexible optoelectronics. Using the Ag NWs/MEH-PPV composite film as the anode on polyethylene terephthalate substrate and combined with a blue organic light emitting devices (OLEDs) unit employing bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(iii)) (Flrpic) in 1,3-bis(carbazol-9-yl)benzene (mCP) as the emitting layer, a highly efficient and chromaticity-stable color-conversion flexible white OLEDs (WOLEDs) is achieved with a maximum current efficiency of 20.5 cd A⁻¹. To the best of our knowledge, this is the highest efficiency reported for color-conversion based flexible WOLEDs. Our work provides an approach to achieving high-performance flexible WOLEDs devices and demonstrates great potential for lighting and display applications.

We have developed a novel color conversion electrode composed of Ag NWs/MEH-PPV via a solution process, which is the first report on a color conversion electrode for applications in flexible optoelectronics.     

Rare-earth-doped TiO2 rutile as a promising ferromagnetic alloy for visible light absorption in solar cells: first principle insights

The electronic structure and magneto-optic properties of TiO₂ (rutile) doped with two concentrations of rare-earth (RE) elements are explored using a first-principle all-electron full-potential augmented spherical-wave method based on the PBEsol–GGA approximation, to examine their potential use as a spintronic and optoelectronic system. The results predict that all compounds exhibit half-metallic character, the only exception is by doping with Nd or that the material is magnetic but the cloud is still a half-metallic magnet. We also found that the localized level at the Fermi energy shifts to lower energy as the atomic number of the 4f-element increases. Consequently, the mechanism that controls the ferromagnetism in these systems has been proposed according to this positioning. The energy of the localized level due to Gd is sufficiently low to lie at the top of the valence band, while Eu produces a midgap state. However, the Fermi level was not noticed precisely at the middle of the energy gap. In contrast, the impurity states of the Nd-, Pm-, and Sm-dopants are close to the bottom of the conduction band of the host system. This allows electrons to be delocalized, and gives a higher scattering cross-section. Interestingly, the analysis of optical absorption and electrical conductivity emphasizes that this ferromagnetic DMS based on rare-earth elements has the power to be a promising spintronic device for visible light absorption in solar cells. Finally, the relationship between the mechanism that controls the ferromagnetism and the absorption efficiency of visible light is discussed.

The electronic structure and magneto-optic properties of TiO₂ (rutile) doped with rare-earth elements are explored using a first-principles all-electron full-potential augmented spherical-wave method, to examine their potential use as a spintronic and optoelectronic system.     

Light transport in turbid media with non-scattering,low-scattering and high absorption heterogeneities based on hybrid simplified spherical harmonics with radiosity model

Modeling light propagation in the whole body is essential and necessary for optical imaging. However, non-scattering, low-scattering and high absorption regions commonly exist in biological tissues, which lead to inaccuracy of the existing light transport models. In this paper, a novel hybrid light transport model that couples the simplified spherical harmonics approximation (SP_N) with the radiosity theory (HSRM) was presented, to accurately describe light transport in turbid media with non-scattering, low-scattering and high absorption heterogeneities. In the model, the radiosity theory was used to characterize the light transport in non-scattering regions and the SP_N was employed to handle the scattering problems, including subsets of low-scattering and high absorption. A Neumann source constructed by the light transport in the non-scattering region and formed at the interface between the non-scattering and scattering regions was superposed into the original light source, to couple the SP_N with the radiosity theory. The accuracy and effectiveness of the HSRM was first verified with both regular and digital mouse model based simulations and a physical phantom based experiment. The feasibility and applicability of the HSRM was then investigated by a broad range of optical properties. Lastly, the influence of depth of the light source on the model was also discussed. Primary results showed that the proposed model provided high performance for light transport in turbid media with non-scattering, low-scattering and high absorption heterogeneities.OCIS codes: (170.3660) Light propagation in tissues, (170.7050) Turbid media, (170.6935) Tissue characterization     

双重血浆分子吸附联合血浆置换治疗慢加急性肝衰竭的疗效分析

目的 观察双重血浆分子吸附系统（DPMAS）联合血浆置换（PE）治疗慢加急性肝衰竭（ACLF）的疗效及安全性。方法 回顾性分析2016年1月至2018年12月我科收治并行人工肝治疗的乙型肝炎ACLF患者69例,其中DPMAS联合PE组32例,单纯PE组37例。观察两组治疗前后血清生化指标、凝血指标和血小板（PLT）的变化,观察疗效及不良反应。结果 两组4周总有效率和12周生存率差异无统计学意义。两组治疗后总胆红素（TBil）、白蛋白（ALB）、总胆汁酸（TBA）差异有统计学意义。两组治疗后与治疗前比较,肝功能及凝血功能均明显好转,差异有统计学意义;联合组PLT治疗前后差异有统计学意义。两组不良反应发生率差异无统计学意义（P＞0.05）。结论 DPMAS联合PE治疗ACLF疗效确切,能减少血浆用量,安全性较高。     

Study of the effect of DIO additive on charge extraction and recombination in organic–inorganic hybrid MAPbI3−xClx perovskite solar cell

In this article, we fabricated a plane structure perovskite solar cell of ITO/PEDOT:PSS/MAPbI_3−xCl_x/PCBM/Al. With 1% of 1,8-diiodooctane (DIO) additive in the perovskite, the solar cell''s efficiency greatly increased from 10.39% to 13.57%. On the one hand, the DIO additive is advantageous to enhance the thin-film degree of crystallinity, and it can enhance the perovskite thin film''s electrical polarization characteristic, leading to an increase in the built-in electric field, and promote charge extraction and separation and transport processes. On the other hand, the DIO additive can also enhance the charge extraction speed in the perovskite solar cell photoelectric conversion process, and further increase the power conversion efficiency (PCE) of the perovskite solar cell. In addition, in the perovskite solar cell device there occurs the monomolecular recombination effect; the DIO additive introduced into the perovskite can effectively reduce the trap-induced monomolecular recombination effect, and enhance the solar cell''s PCE.

The additive of DIO not only can increase the PCE of perovskite solar cell, but also can decrease the bimolecular recombination.     

Mesenchymal stem cell function on hybrid organic/inorganic microparticles in vitro

The aim of this study was to investigate mesenchymal stem cell (MSC) function on novel type hybrid organic/inorganic microparticles (MPs) for application to bone regeneration. The MPs were based on chitosan (CS) and consisted of inorganic components, such as dibasic calcium phosphate (CaHPO₄) or calcium carbonate (CaCO₃). The MPs were crosslinked using tripolyphosphate. Four types of hybrid MPs were fabricated: CS; CS–10% CaHPO₄; CS–20% CaHPO₄; and CS–10% CaCO₃. The MSCs were attached to all the types of MPs at day 1 and started to spread and proliferate further by days 2 and 7, as analysed by fluorescence microcopy. Cell proliferation was measured at days 7, 14, 21 and 28 by counting the cells attached on the MPs. The number of proliferated cells increased significantly for all types of MPs as time increased. MSC differentiation was analysed using osteoblast (OB) phenotype markers, including alkaline phosphatase activity (ALP), collagen I (COLLI) and osteocalcin (OCN) at days 7, 14, 21 and 28, using quantitative real‐time PCR. The normalized mRNA expression of ALP for all MPs was observed only at day 7. The normalized mRNA expression of COLLI and OCN was significantly increased for all types of hybrid MPs at each time point compared to the control samples. Collectively, our results proved that hybrid organic/inorganic MPs were non‐cytotoxic and supported MSC attachment, spreading, proliferation and differentiation into the OB phenotype. These hybrid MPs have great potential for application as bone‐void fillers or bone tissue engineering scaffolds in bone regeneration. Copyright © 2009 John Wiley & Sons, Ltd.     

Dual function of molybdenum sulfide/C-cloth in enhancing the performance of fullerene nanosheets based solar cell and supercapacitor

Quantum dot solar cells (QDSCs) with hexagonal fullerene nanosheets (C₆₀-NS) embedded in a titanium oxide/cadmium sulfide (TiO₂/CdS) photoanode coupled with a carbon-cloth (C-cloth) coated with molybdenum sulfide (MoS₂) counter electrode (CE) are studied for the first time. C₆₀-NS due to a favorable work function of 4.57 eV and a conductance of 1.44 μS, enable faster electron injection from the conduction band of cadmium sulfide to the current collector, in contrast to the bulk fullerene based TiO₂/CdS solar cell. The champion cell with the TiO₂/C₆₀-NS/CdS photoanode and a MoS₂/C-cloth CE exhibits a high power conversion efficiency of 5.6%, greater by ∼14% relative to its'' analogue cell with bulk fullerene. A large area cell of 1 cm² dimensions with TiO₂/C₆₀-NS/CdS gives a PCE of 2.9%. The effect of MoS₂ in improving the efficiency of the cell with a TiO₂/C₆₀-NS/CdS photoanode is realized in terms of enhanced electrocatalytic activity for polysulfide reduction, and lower charge transfer resistance at the polysulfide/CE interface compared to a cell with the same photoanode but having pristine carbon-cloth as the CE. The ability of MoS₂ for catalyzing the oxidized polysulfide species at the CE and C₆₀-NS for improving the charge collection at the photoanode serve as indicators for their wider utilization in solar cells. It also serves as a good supercapacitor material. A MoS₂/C-cloth based symmetric cell exhibits a specific capacitance of 645 F g⁻¹ at 2 A g⁻¹, which shows its'' potential for energy storage as well. By integrating the QDSC and the supercapacitor, the resulting integrated device acquires a photovoltage of 0.7 V, under 1 sun illumination.

Molybdenum sulfide/carbon-cloth electrode is an efficient counter electrode for fullerene nanosheets based solar cell and it also serves as an effective energy storage material.     

基于杂合型ASL改进静音MRA在脑血管成像中的价值初探

目的通过杂合型标记策略改进静音磁共振血管成像(magnetic resonance angiography,MRA)技术,并比较探讨杂合型静音MRA在提升脑血管成像质量中的价值.材料与方法分别采集纳入的24名健康受试者及5例脑动静脉畸形(arteriovenous malformation,AVM)患者杂合型以及连续型...     

Polarized multispectral imaging in a rigid endoscope based on elastic light scattering spectroscopy

Elastic light scattering spectroscopy (LSS) is widely utilized to investigate cellular structures in cultured cells and various tissues. However, few imaging systems, especially endoscopic imaging systems, can implement LSS. It is the aim of this work to create a polarized multispectral imaging system based around a rigid endoscope to detect micrometer sized particles using LSS. The instrument first validated with different sized mono-disperse polystyrene microspheres, then an image is reconstructed based on LSS which shows the differentiation of different sized microspheres. Finally a preliminary experiment is conducted to demonstrate its capability to discriminate different types of cells.OCIS codes: (170.2150) Endoscopic imaging, (290.5855) Scattering, polarization, (110.4234) Multispectral and hyperspectral imaging     

The roles of fused-ring organic semiconductor treatment on SnO2 in enhancing perovskite solar cell performance

It took only 11 years for the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to increase from 3.8% to 25.2%. It is worth noting that, as a new thin-film solar cell technique, defect passivation at the interface is crucial for the PSCs. Decorating and passivating the interface between the perovskite and electron transport layer (ETL) is an effective way to suppress the recombination of carriers at the interface and improve the PCE of the device. In this work, several acceptor–donor–acceptor (A–D–A) type fused-ring organic semiconductors (FROS) with indacenodithiophene (IDT) or indacenodithienothiophene (IDDT) as the bridging donor moiety and 1,3-diethyl-2-thiobarbituric or 1,1-dicyromethylene-3-indanone as the strong electron-withdrawing units, were deposited on the SnO₂ ETL to prepare efficient planar junction PSCs. The PCEs of the PSCs increased from 18.63% for the control device to 19.37%, 19.75%, and 19.32% after modification at the interface by three FROSs. Furthermore, impedance spectroscopy, steady-state and time-resolved photoluminescence spectra elucidated that the interface decorated by FROSs enhance not only the extraction of electrons but also the charge transportation at the interface between the perovskite and ETL. These results can provide significant insights in improving the perovskite/ETL interface and the photovoltaic performance of PSCs.

A series of n-type FROSs called IDT-T, IDT-I, and IDDT-T were used to passivate the interface between the perovskite layer and SnO₂ layer in PSCs, leading to reduced interfacial loss in hopes of enhancing the performance of PSCs.     

Brain tissue segmentation in MR images based on a hybrid of MRF and social algorithms

Effective abnormality detection and diagnosis in Magnetic Resonance Images (MRIs) requires a robust segmentation strategy. Since manual segmentation is a time-consuming task which engages valuable human resources, automatic MRI segmentations received an enormous amount of attention. For this goal, various techniques have been applied. However, Markov Random Field (MRF) based algorithms have produced reasonable results in noisy images compared to other methods. MRF seeks a label field which minimizes an energy function. The traditional minimization method, simulated annealing (SA), uses Monte Carlo simulation to access the minimum solution with heavy computation burden. For this reason, MRFs are rarely used in real time processing environments. This paper proposed a novel method based on MRF and a hybrid of social algorithms that contain an ant colony optimization (ACO) and a Gossiping algorithm which can be used for segmenting single and multispectral MRIs in real time environments. Combining ACO with the Gossiping algorithm helps find the better path using neighborhood information. Therefore, this interaction causes the algorithm to converge to an optimum solution faster. Several experiments on phantom and real images were performed. Results indicate that the proposed algorithm outperforms the traditional MRF and hybrid of MRF-ACO in speed and accuracy.     

Rational design of near-infrared dyes based on boron dipyrromethene derivatives for application in organic solar cells

With the aim to further improve the light-absorption efficiency of organic solar cells (OSCs), we have designed a series of novel pyrrolopyrrole boron dipyrromethene (BODIPY) derivatives by replacing the sulfur atom and introducing different fused aromatic heterocycle end-caps. The optical, electronic, and charge transporting properties of the designed molecules have been systematically investigated by applying density functional theory (DFT) and time-dependent DFT (TD-DFT) methodologies. The calculated the frontier molecular orbital (FMO) energies and spectral properties showed that the designed molecules exhibit narrower band gaps and strong absorption in the red/near-infrared (NIR) region, which led to the higher light-absorbing efficiency. Furthermore, the calculated reorganization energies show that the designed molecules are expected to be promising candidates for hole and/or electron transport materials. The results reveal that the designed molecules can serve as high-efficiency red/NIR-active donor materials as well as hole and/or electron transport materials in OSC applications.

A series of novel pyrrolopyrrole boron dipyrromethene derivatives have been designed as high-efficiency red/near-infrared-active donor materials and charge transport materials in OSC applications.     

Effect of counter-ions on the properties and performance of non-conjugated polyelectrolyte interlayers in solar cell and transistor devices

We have investigated a series of non-conjugated polyelectrolytes (NPEs) which are based on a polyethylenimine (PEI) backbone with various counterions, such as Br⁻ I⁻ and BIm₄⁻, as interfacial layers at the electrodes of solar cells and transistor devices to improve the power conversion efficiency (PCE) and device performance. This new series of NPEs with different counterions are capable of forming electric dipoles at NPE/metal electrode interfaces; as a consequence tuning of the energy levels, and work function (WF) of the electrodes is possible. Using this approach, the PCE of organic solar cells could be improved from 1.05% (without NPEs) to 6.77% (with NPEs) while the charge carrier mobility and on/off ratio of FET devices could be improved, showing the broad utility of this type of material. This study provides a novel approach towards investigating the influence of ions on interfacial dipoles and electrode WFs in solution-processed semiconducting devices.

Non-conjugated polyelectrolytes are empolyed as interfacial layers at the electrodes of solar cells and transistor devices to improve the power conversion efficiency (PCE) and device performance.