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Copper (Cu) is present not only in the electrode for inverted-structure halide perovskite solar cells (PSCs) but also in transport layers such as copper iodide (CuI), copper thiocyanate (CuSCN), and copper phthalocyanine (CuPc) alternatives to spiro-OMeTAD due to their improved thermal stability. While Cu or Cu-incorporated materials have been effectively utilized in halide perovskites, there is a lack of thorough investigation on the direct reaction between Cu and a perovskite under thermal stress. In this study, we investigated the thermal reaction between Cu and a perovskite as well as the degradation mechanism by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Kelvin probe force microscopy (KPFM). The results show that high temperatures of 100 °C induce Cu to be incorporated into the perovskite lattice by forming "Cu-rich yet organic A-site-poor" perovskites, (Cu

Many studies have recently produced artificial enzymes with metal nanoparticles (NPs) to overcome the limitations of natural enzymes, such as low stability, high cost, and storage problems. In particular, gold NPs exhibit peroxidase-like activity and are strongly influenced by external parameters, such as pH, temperature, size, shape, and functional layer, which change the enzyme activity. Here, chitosan-capped multibranched Au-Ag-Pt NPs (CCNPs) that mimic peroxidase were synthesized using various peroxidase-mimicking strategies. The results demonstrated that enzyme activity sequentially increased because of the multibranched Au-Ag NPs coated with Pt and chitosan. The enzyme activity of the particle was evaluated through the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), which causes a color change into blue. This change was observable with the naked eye and could be used practically. The color change depended on the concentration of hydrogen peroxide (H

Exposure to certain chemicals such as disinfectants through inhalation is suspected to be involved in the development of pulmonary fibrosis, a lung disease in which lung tissue becomes damaged and scarred. Pulmonary fibrosis is known to be regulated by transforming growth factor β (TGF-β) and peroxisome proliferator-activated receptor gamma (PPARγ). Here, we developed an adverse outcome pathway (AOP) to better define the linkage of PPARγ antagonism to the adverse outcome of pulmonary fibrosis. We then conducted a systematic analysis to identify potential chemicals involved in this AOP, using the ToxCast database and deep learning artificial neural network models. We identified chemicals bearing a potential inhalation hazard and exposure hazards from the database that could be related to this AOP. For chemicals that were not present in the ToxCast database, multilayer perceptron models were developed based on the ToxCast assays related to the AOP. The reactivity of ToxCast untested chemicals was then predicted using these deep learning models. Both approaches identified a set of chemicals that could be used to validate the AOP. This study suggests that chemicals categorized using an existing database such as ToxCast can be used to validate an AOP and that deep learning approaches can be used to characterize a range of potential active chemicals for an AOP of interest.

Polydiacetylene (PDA) is a versatile polymer that has been studied in numerous fields because of its unique optical properties derived from alternating multiple bonds in the polymer backbone. The conjugated structure in the polymer backbone enables PDA to possess the ability of blue-red colorimetric transition when π-π interactions in the PDA backbone chain are disturbed by the external environment. The chromatic property of PDA disturbed by external stimuli can also emit fluorescence in the red region. Owing to the unique characteristics of PDA, it has been widely studied in facile and label-free sensing applications based on colorimetric or fluorescence signals for several decades. Among the various PDA structures, membrane structures assembled by amphiphilic molecules are widely used as a versatile platform because facile modification of the synthetic membrane provides extensive applications, such as receptor-ligand interactions, resulting in potent biosensors. To use PDA as a sensory material, several methods have been studied to endow the specificity to PDA molecules and to amplify the signal from PDA supramolecules. This is because selective and sensitive detection of target materials is required at an appropriate level corresponding to each material for applicable sensor applications. This review focuses on factors that affect the sensitivity of PDA composites and several strategies to enhance the sensitivity of the PDA sensor to various structures. Owing to these strategies, the PDA sensor system has achieved a higher level of sensitivity and selectivity, enabling it to detect multiple target materials for a full field of application.

Ge surfaces were etched by means of metal-assisted chemical etching (MaCE). The behavior of the MaCE reaction in diluted H 2 O 2 was compared with that of a conventional etchant of HF/H 2 O 2 /H 2 O mixture (FPM). Herein we first report that a pyramidal structure on Ge (0 0 1) can be prepared by MaCE in dilute H 2 O 2 solution, without the use of HF. Contrastingly, an octagonal trench structure was prepared by 4/5/1 FPM treatment of Ge (0 0 1) surface. This octagonal structure consisted of a square base, four large facets connected to the base, and other four small facets adjacent to the four large facets, which were considered to be (0 0 1), {1 1 0}, and {1 1 1}, respectively. The octagonal trench was formed as a result of the difference in etch rate of Ge depending on the orientation: {1 0 0} > {1 1 0} > {1 1 1}. Ge surfaces treated by MaCE exhibited improved solar cell efficiency due to their improved light absorption, which led to significant increases in the cells’ short circuit current and fill factor. The results suggest that optimized MaCE procedures can be an effective method to improve the performance of Ge-based photovoltaic devices.

We present the synthesis of surface-fluorinated, rutile-rich, meso-macroporous TiO2 nanofibers via simple post-treatment in a 5% hydrogen fluoride solution at room temperature and atmospheric pressure. Using various characterization methods, we demonstrate that the anatase phase of the nanofiber can be used as a sacrificial template to ensure appropriate porosity characteristics in the TiO2 nanofibers. From scanning electron microscopy results, it was confirmed that the dimensions of the nanofibers do not change after the hydrogen fluoride post-treatment. However, x-ray diffraction and transmission electron microscopy results confirm that the proportion of the rutile phase increases after hydrogen fluoride post-treatment. After hydrogen fluoride treatment, small pores with diameter below 10 nm almost disappear, and the pore size distribution ranges from mesopore (

In the solution-based preparation of CZTS (Cu 2 ZnSnS 4 ) thin films followed by a sulfurization process, a layer of MoS 2 is formed at the CZTS–Mo interface. Formation of this MoS 2 layer is mainly governed by the sulfurization process in H 2 S ambient gas rather than diffusion of a sulfur source in the CZTS film. Growth of CZTS grain and grain boundaries facilitates the formation of a MoS 2 layer in any sulfurization process. A decrease in the series resistance and an increase in the current density and solar cell efficiency were achieved through an increase in the temperature of the second sulfurization sequence in a two-step sulfurization sequence. The formation of a CZTS grain dominates the performance of CZTS thin film solar cells with a relatively thin MoS 2 layer, but the performance is degraded by an increase in recombination rate and the hole barrier effect between CZTS and Mo when the MoS 2 is sufficiently thick.

A silicon nanowire structure was fabricated using the electrochemical electroless etching method, involving electroless plating and the electrochemical etching process. The reflection of the absorption layer with the nanowires' structure was about 5%, which is better than a bulk-type solar cell (10%).

A double textured selective emitter (DTSE) solar cell was fabricated using Si wafer. The 40 × 40 mm 2 silicon substrates were textured to form a pyramid-shaped surface, and nanowires were fabricated by a metal-assisted chemical etching process using Ag nanoparticles. All surface modifications of the micro and nanostructures were done by a wet-based process. The heavily doped and shallow emitters for selective emitter solar cells were prepared through the POCl 3 diffusion and a chemical etch-back process, respectively. The front and rear electrodes were prepared with a conventional screen printing method. The optical properties were enhanced through the double textured (DT) structure, and additional enhancement of the electrical properties was realized through the selective emitter concept. The DTSE solar cell achieved a higher conversion efficiency of 17.9% with improved absorption and short circuit current density compared to a DT solar cell.

In-doped ZnO thin films were prepared by a sol–gel spin coating method. Since several issues with In doping have been reported, such as degradation of crystallinity and deterioration of electrical resistivity at high In-doping levels, co-doping with Ga and electron beam treatment was demonstrated in this study. When In dopant was added to the ZnO thin film at 0.5 mol%, it increased the carrier concentration, thereby reducing the resistivity of the film. In contrast, further doping by Ga in the presence of In did not significantly change the electrical properties. When electron beam treatment was conducted on ZnO films, the optical band gap was increased and the carrier concentration and mobility were increased. In particular, a 0.5 mol% In-doped ZnO that received electron beam treatment at 2 keV exhibited an electrical resistivity as low as 4.8 × 10−2 Ω cm, while 57.1 Ω cm was obtained from the pristine ZnO thin film. When the ZnO films were applied to crystalline Si solar cells, conversion efficiency significantly increased from 10.37 % for the cell with pristine ZnO thin film to 11.45 % with the In-doped and electron beam-treated ZnO thin film.

Cu2ZnSnS4 (CZTS) absorber layers were prepared from copper acetate, zinc acetate, tin chloride, and thiourea in a solution of methanol, ethylenediamine, and ethanolamine using a sol–gel spin-coating method. Sol–gel precursor solutions were prepared with different metal salt ratios, and the effects on film growth, optical properties, and crystal properties of CZTS films were investigated. In addition, the role of sulfurization temperature on grain size of CZTS and formation of the MoS2 layer at the CZTS and Mo interface were investigated. By changing the metal salt ratio in the precursor solution, a Zn-rich and Cu-poor condition in the CZTS film was obtained. By preparing Zn-rich and Cu-poor CZTS film with a thinner MoS2 layer at a lower sulfurization temperature, the CZTS cell efficiency was improved, and a conversion efficiency of 1.22 % was obtained.

Transparent conductive zinc oxide (ZnO) thin films were synthesized by a sol–gel spin coating method with the addition of Ga(NO 3 ) 3 in a Zn(CH 3 COO) 2 solution and exposed to electron beam treatment. The UV–Vis spectra demonstrated that all of the films had transmittances of over 85% in the visible region. When Ga(NO 3 ) 3 was added to the ZnO precursor solution, the resistivity of the ZnO thin film decreased and the carrier concentration increased significantly. After electron beam treatment was performed on the 0.4 at.% Ga-doped ZnO film, the optical band gap increased and the resistivity significantly decreased resulting from the increases of the carrier concentration and mobility. By combining Ga doping and electron beam treatment, the resistivity of the ZnO thin film was reduced by a factor of nine hundred.

An electron-beam annealing method has been adapted for rapid crystallization of p-type amorphous-silicon thin films deposited by using an evaporation method. The amorphous phase of silicon thin-film was crystallized by using an accelerating DC voltage higher than the 4.0 kV for 120 s. From the crystalline properties, the nanocrystalline silicon thin film after electron-beam annealing showed mainly (111), (220), and (311) orientations and a crystalline volume fraction (Xc) of 93.6%. The crystalline properties improved with increasing DC voltage for rapid annealing times. The electron-beam annealing method can be a powerful method for achieving rapid crystallization of amorphous materials.

We report a simple and green process to prepare poly(vinyl alcohol)/carbon nanotube (PVA/CNT) composite fibers having high mechanical properties. This process, an environmentally friendly one with no use of acid or hazardous solvent, produces the composite fibers utilizing a PVA layer pre-coated on a PET film. SEM micrographs indicated that the CNTs are well dispersed in the PVA matrix, and the diameter of the fiber is around 50 μm. Mechanical properties of the composite fiber treated at different thermal annealing conditions are also reported.

Undoped and Al-doped ZnO thin films were prepared by a sol–gel spin coating method. The films were exposed to the electron beam at different energies to improve their electrical properties by modifying their film crystallinity. For both the undoped and Al-doped ZnO thin films, the carrier concentration significantly increased and the resistivity decreased after the introduction of the energetic electron beam. Since band gap widening of the undoped and Al-doped ZnO thin films was also observed with exposure to the electron beam, the behaviors and tendencies can be explained by the Burstein–Moss effect. The effects of the electron beam on ZnO thin film properties, including band gap widening, increasing carrier concentration, and significantly decreased resistivity, were similar to the effects of Al doping in ZnO. Finally, by combining electron beam treatment and Al doping of ZnO thin films prepared by a sol–gel method, the resistivity of the sol–gel synthesized ZnO thin film decreased from 5.8 × 10 2 Ω cm to 8.2 × 10 − 2 Ω cm. According to the Monte Carlo simulation of electron penetration in the ZnO thin film, the penetration depth increased with electron beam energy, which induced lattice heating and atomic rearrangement by electronic excitation in a collision cascade.

The silicon (Si) microwires were fabricated by microsphere lithography using polystyrene (PS) beads monolayer. The Si wafer tailored into 40 x 40 mm2 was used as a substrate. The monolayer of 2.0 μm-sized PS beads was formed on substrates through convective assembly method. PS beads on substrates were tailored into smaller sizes by O2 plasma treatment using reactive ion etching (RIE). This controllable re-sizing process gave an opportunity to prepare the wire-array with various radii of Si microwires fabricated by using inductively coupled plasma (ICP)-etching. The convective assembly process was monitored in real-time through an optical microscope with a CCD camera. PS beads and structures of Si microwires were characterized using a scanning electron microscope (SEM) and the optical property was measured by the UV-Vis spectroscopy.

To investigate the significance of p63 expression in uterine cervical and endometrial cancers.DeltaNp63 protein expression was studied in a variety of 127 cases of uterine cervical lesions (20 non-neoplastic cervices, 43 cervical intraepithelial neoplasia [CIN], 54 squamous cell carcinomas (SCCs), 40 adenocarcinomas, and 13 other histologic types) and 30 endometrioid type of endometrial adenocarcinomas by using immunohistochemistry. One SCC cell line (ME-180) and one adenocarcinoma cell line (HeLa) were also included.In uterine cervix, the expression of DeltaNp63 was increased with progression of CIN, and positive in all SCCs, transitional cell carcinomas, and adenoid basal carcinoma, but negative in all adenocarcinomas. Adenosquamous cell carcinoma and mixed neuroendocrine and squamous cell carcinoma were positive in squamous component, but not in adenocarcinoma and neuroendocrine carcinoma components. ME-180 cell line was positive, whereas HeLa cell line was negative. Endometrioid type of endometrial adenocarcinomas showed a positive staining in glandular (26.7%) and squamous component.Immunohistochemical staining for DeltaNp63 is a powerful marker for squamous differentiation and useful in exclusion of glandular and neuroendocrine differentiation in uterine cervical cancers, but not always in endometrial cancers.

We report our discovery of a new process to produce composite carbon nanotubes (CNT) fibers from single-walled carbon nanotubes (SWNTs), multi-walled nanotubes (MWNTS) or the combinations thereof utilizing already an adhesive (polymer) coated layer on polyethylene terephthalate (PET) film strip by simply applying CNT coating on the layer followed by an acid dipping. We also found that applying either an additional base treatment or an additional polyvinyl alcohol (PVA) polymer coating to the CNT-coated strip after the strip was dipped in acid enables us to achieve even higher mechanical properties compared to the former process.