Zn Films Research Articles

Promising Cd-free double buffer layer in CZTSSe thin film solar cells

Zn(O,S) film is widely used as a Cd-free buffer layer for kesterite thin film solar cells due to its low-cost and eco-friendly characteristics. However, the low carrier concentration and conductivity of Zn(O,S) will deteriorate the device performance. In this work, an additional buffer layer of In2S3 is introduced to modify the properties of the Zn(O,S) layer as well as the CZTSSe layer via a post-annealing treatment. The carrier concentrations of both the Zn(O,S) and CZTSSe layers are increased, which facilitates the carrier separation and increases the open circuit voltage (VOC). It is also found that ammonia etching treatment can remove the contamination and reduce the interface defects, and there is an increase of the surface roughness of the In2S3 layer, which works as an antireflection layer. Consequently, the efficiency of the CZTSSe solar cells is improved by 24% after the annealing and etching treatments. Simulation and experimental results show that a large band offset of the In2S3 layer and defect energy levels in the Zn(O,S) layer are the main properties limiting the fill factor and efficiency of these CZTSSe devices. This study affords a new perspective for the carrier concentration enhancement of the absorber and buffer layers by In-doping, and it also indicates that In2S3/Zn(O,S) is a promising Cd-free hybrid buffer layer for high-efficiency kesterite solar cells.

The effect of laser fluences on the structural and optoelectronic properties of Zn(O,Se) films

Zinc oxy-selenide (Zn(O,Se)) is a prospective semiconductor that could be applied as a buffer layer in optoelectronic devices as an alternative for toxic CdS layers. A complete investigation of the effect of changing laser fluences from 4 to 6 J cm−2 on the phase composition,optical and electrical properties of Zn(O,Se) films prepared by pulsed laser deposition in a high vacuum at 500°C is reported. Deposited Zn(O,Se) films were characterized using HR-SEM, XRD, UV–Vis, and Hall effect measurements. HR-SEM micrographs illustrated the deposition of uniform, adherent, and compact Zn(O,Se) films. XRD investigation confirmed the formation of a Zn(O,Se) phase at 500°C for all three laser fluences. In addition, the UV–Vis transmittance spectra indicated the relative transparency of the deposited films in the visible range, accompanied by a redshift in the absorption edges as the laser fluences increased. Electrical measurements showed a significant increase of the electron concentration and electrical conductivity in the obtained films as laser fluence increased to 6 J cm−2.

Facile Synthesis of ZnO Thin Films at Low Temperatures Using an Additive-Free Electrochemical Oxidation Method

Because of their simplicity and low equipment costs, various oxidation methods can be used to create metal oxides, but they still require long processing times and/or high temperatures. In this study, a new electrochemical oxidation (ECO) method, which oxidizes metal in DI water with a constant flowing current to both the cathode and anode, was developed to overcome the disadvantages of conventional oxidation methods. The mechanism of the ECO method is discussed. Metallic Zn films were oxidized by the ECO method in DI water for 1 h. The DI water temperature was varied from 30 to 90 <sup>o</sup>C to determine the optimal temperature for the ECO process. Increasing the temperature of the DI water led to distinct surface changes in the disk-shaped Zn plate. The intensity of diffraction peaks from the ZnO (002) plane gradually increased from 31.67 to 2806.48. The structural and optical properties of the ZnO thin film were enhanced as the temperature of the DI water approached 90 <sup>o</sup>C, which means that a high-quality ZnO thin film was synthesized using the ECO method at lower temperatures and shorter processing time compared with established oxidation methods. These results confirm the ECO method can be useful for the low-cost fabrication of transparent and flexible optoelectronic devices.

Improved optoelectronic properties of Terbium co-doped CdO:Zn thin films coated by nebulizer spray pyrolysis method

Abstract Terbium co-doped CdO:Zn thin films have been coated by the facile and an efficient spray pyrolysis technique on the substrate of glass to tune its optical and electrical properties. From XRD analysis, all the diffraction peaks strongly exhibit polycrystalline nature with perfect cubic structure followed by preferential orientation was changed from (111) plane to (200) plane. The nature of the crystal structure and crystallite size is reduced from 20.4 to 16.5 nm by increasing Tb doping concentration due to defects in the lattice. The atomic force microscope AFM mages clearly show that the film's grain size decreases with the Tb dopant. The elements such as Cd, Zn, O, and Tb exists in the elemental mapping and EDS spectra. The transmittance is varied from 70, to 82% at 800 nm, and the maximum bandgap of 3.06 eV is observed for 1.5 wt.% degenerate doping concentration. PL emission at 435 nm shows a high intense peak attribute to the crystalline quality of the film. The electrical property of the film has been greatly improved with doping concentration, which is useful for optoelectronic devices. The TCO based on the 1.5 wt.% Tb co-doped CdO:Zn film shows an improved performance (higher transmission of 82%, lowest resistivity of 7.48 × 10−4 Ω cm, the highest carrier concentration of 11.3×1020 cm−3). These results propose a much simpler route to achieve high-quality Terbium co-doped CdO:Zn thin films for TCO applications.

Enhancement in optoelectronic nature of facile spray fabricated Ce co-doped CdO:Zn films for TCO applications

Cerium co-doped CdO:Zn (Ce@CdO:Zn) transparent conducting oxide films were deposited onto glass by a cost-effective nebulizer spray procedure. X-ray diffraction (XRD) investigation on films shows that formation of cubic structure with (111) and (200) orientations for CdO:Zn and Ce@CdO:Zn films, respectively. Surface topography study discovered the foundation of compact grains for 1.5 wt.% Ce-doped film. EDX spectrum possesses the Cd, Zn, and Ce in Ce doped CdO:Zn film. Ce doped films exhibited maximum transparency and highest bandgap (Eg) value in comparison with pristine CdO:Zn film and the Eg values are noticed between 2.64–2.87 eV. Hall-Effect study evinced that Ce doping enhanced the contents of the carrier and lessen the electrical resistivity. The ρ values cut from 9.84 × 10–3 Ω cm to 6.40 × 10−4 Ω cm when Ce % rise from 0–1.5 wt.%. The obtained carrier concentration value of CdO:Zn is 4.02 × 1019 cm−3 and enlarged to 8.72 × 1020 cm−3 for 1.5 wt.% Ce co-doped film. The Figure of merit amplified from 1.1–9.4 × 10−4 Ω−1 on growing the Ce content to 1.5 wt.% from 0.

EFFECT OF OXIDATION TIME ON STRUCTURAL AND OPTICAL PROPERTIES OF ZNO FILMS PREPARED BY HYDROTHERMAL OXIDATION OF ELECTRODEPOSITED ZN COATING ON ITO SUBSTRATE

In this work, hydrothermal oxidation of electrodeposited zinc coatings is used to produce zinc oxide (ZnO) films. In the first step, zinc (Zn) coating is electrodeposited on indium tin oxide (ITO) coated glass substrate. The Zn films are then immersed in deionized water at [Formula: see text]C. The exposure time of Zn coating in deionized water is varied from 1[Formula: see text]h to 24[Formula: see text]h in sequence. At the 24[Formula: see text]h exposure time, X-ray diffraction (XRD) patterns reveal that zinc film has been completely converted to ZnO. Scanning electron microscope (SEM) results show morphological changes from flakes (for pure Zn) or 2D plates to rod (ZnO) like morphology which further changes to cotton-flower like shapes with an increase in oxidation time. Diffuse reflectance spectral measurements show the band gap tuning with oxidation time (it decreases from 3.28[Formula: see text]eV to 3.19[Formula: see text]eV). Photoluminescence (PL) spectra have depicted phonon replicas with energy separation of [Formula: see text][Formula: see text]meV for the ZnO films obtained after 6 and 12[Formula: see text]h exposure time in deionized water at [Formula: see text]C temperature.

Properties of thermally evaporated CZTS thin films and numerical simulation of earth abundant and non toxic CZTS/Zn(S,O) based solar cells

Earth abundant Cu2ZnSnS4 (CZTS) films were grown by thermal evaporation technique onto non heated substrates. As deposited CZTS films were annealed under two different atmospheres: (1) vaccum annealing atmosphere and (2) sulfur annealing atmosphere followed by vacuum annealing. The samples were analyzed for their microstructural, electrical and optical properties before and after annealing. X-Ray Diffraction (XRD) analysis revealed that the as deposited film was amorphous whereas the annealed ones were polycrystalline with a highly (1 1 2) orientation. Raman spectroscopy confirmed the phase purity of annealed CZTS films. Both annealing atmospheres were found to decrease the band gap energy and the resistivity of the samples. All films exhibited p-type electrical conductivity. Numerical simulation of earth abundant CZTS thin film solar cells with non toxic Zn(S,O) buffer layer was performed by Solar Cell Capacitance Simulator (SCAPS-1D) using the experimental results obtained for CZTS and Zn(S,O) films. Zn(S,O) was used to substitute toxic CdS in earth-abundant Cd-free CZTS solar cells. A maximum conversion efficiency of 12.60% was obtained for Mo/p-Cu2ZnSnS4/n-Zn(S,O)/i-ZnO/n-ZnO:Al structure with CZTS film annealed under sulfur annealing atmosphere followed by vacuum annealing.

Reactively sputtered Zn(O,S) buffer layers for controlling band alignment of Cu(In,Ga)Se2 thin-film solar cell interface

Abstract Buffer layers in Cu(In,Ga)Se2 (CIGS) solar cells are highly preferable to be vacuum-compatible and use non-toxic materials not only for the film but also for the manufacturing process. Moreover, high controllability for the energy levels of buffer layers is greatly desirable for achieving higher solar cell efficiency because the buffer layer is formed directly onto the absorber layer which generates carriers. In this study, the S/(O + S) composition ratio of the Zn(O,S) thin films was finely controlled by varying O2/(Ar + O2) gas flow ratio using a reactive sputtering method including an Ar/O2 mixture gas and a single ZnS sputter target. The structural, electrical, and photovoltaic performance properties of the Zn(O,S) thin films and their CIGS solar cells were investigated at varied S/(O + S) composition ratios. As the S/(O + S) composition ratio of the Zn(O,S) films increased, bandgap bowing occurred with the increase of the conduction band and valence band energy levels. The photovoltaic performance was greatly influenced by the difference of the conduction band energies between the Zn(O,S) buffer and the CIGS absorber. When the conduction band energy of the Zn(O,S) was too high or too low compared to that of the CIGS, it increased the carrier recombinations or series resistance, respectively, which induced losses of the open-circuit voltage and the fill factor. The controlling and optimizing the energy levels at the Zn(O,S)/CIGS interface were crucial for improved solar cell performances.

Cd-Free Zn(O,S) as Alternative Buffer Layer for Chalcogenide and Kesterite Based Thin Films Solar Cells: A Review.

Cd is categorized as a toxic material with restricted use in electronics as there are inherent problems of treating waste and convincing consumers that it is properly sealed inside without any threat of precarious leaks. Apart from toxicity, band-gap of CdS is about 2.40-2.50 eV, which results significant photon loss in short-wavelength range which restricts the overall performance of solar cells. Thin film of Zn(O,S) is a favorable contender to substitute CdS thin film as buffer layer for CuInGaSe₂ (CIGS), CuInGa(S,Se)₂ (CIGSSe), Cu₂ZnSn(S,Se)₄ (CZTSSe) Cu₂ZnSnSe₄ (CZTSe), Cu₂ZnSnS₄ (CZTS) thin film absorber material based photovoltaic due to it made from earth abundant, low cost, non-toxic materials and its ability to improve the efficiency of chalcogenide and kesterite based photovoltaic due to wider band-gap which results in reduction of absorption loss compared to CdS. In this review, apart from mentioning various deposition technique for Zn(O,S) thin films, changes in various properties i.e., optical, morphological, and opto-electrical properties of Zn(O,S) thin film deposited using various methods utilized for fabricating solar cell based on CIGS, CIGSSe, CZTS, CZTSe and CZTSSe thin films, the material has been evaluated for all the properties of buffer layer (high transparency for incident light, good conduction band lineup with absorber material, low interface recombination, high resistivity and good device stability).

Analysis on Sensitivity of Semiconductor Methane Gas Sensors by Ultrasonic Process

The thin films of Pt and Zn were coated with on the electrode in the board. Thin films of Pt are fabricated by ion plasma and Zn is manufactured by DC sputtering methods. Then the deposited boards were produced by ultrasonic chemical deposition in 0.01 M aqueous solution of C6H12N4 and Zn(NO3)2∙6H2O. To make the ZnO prepared-substrates were heat-treated at 600 °C for 1 hour and the sensitivity of ZnO-structured sensors was tested for Methane gas. In the experiment, the concentrations of Methane gas ranged from 15% to 40% LEL. We measured the change of the voltage before and after the Methane gas injections to judge whether it had a suitable performance as the Methane gas sensors. As a result of the sensitivity of the fabricated sensor, it was found that the voltage increases according to the Methane concentration. The sensitivity of the sensor constantly increased, so the graph showed a linear shape. Also, the fabricated sensors showed very short stabilization time, fast reaction and recovery. As a result, the using possibility of the detector is suggested where detection is required.

Porosity Study in ZnO Films for Carbon Monoxide Sensing

The development of gas sensors to monitor the toxic and combustible gases is imperative due to the concerns for environmental pollution and the safety requirements for the industry. In general, sensors provide an interface between the electronic equipment and the physical world typically by converting nonelectrical physical or chemical quantities into electrical signals [1]. The fundamental sensing principle relies on the change of conductivity of the sensors when they are exposed to certain target gases at moderate temperatures. One of the demands on the gas sensors is the low power consumption because the sensors work from day-to-day [2]. A low resistance material provides the lower driving power when it is used as a sensor. Among various metal oxide semiconductors (SMOs), typical n-type Zinc oxide (ZnO) with merit features such as wide direct band gap of 3.37 eV, good morphology properties, high electron mobility, low production cost, excellent chemical properties and appropriate response toward gaseous species such as carbon monoxide gas (CO), is widely used in the resistance-type CO gas sensors[3-4]. This work reports the response to carbon monoxide by using ZnO films with controlled pore size. Zn films were deposited on silicon substrates by DC sputtering using Zn targets of 2 in diameter with a purity of 99.99%. The (0 0 1) P type silicon substrates have a size of 1.5 x 1.5 cm2. The substrates were cleaned using the conventional cleaning procedure based on xylene, acetone and propanol to eliminate probably residues of adhesives. A 30-Watt power and a pressure of 5.5 mTorr were used for the deposition. Under these processing conditions for a sputtering period of 20 min, Zn films of 50 nm in thickness were grown as measured by profilometry. The samples were placed in a quartz furnace with a chromatographic N2 flow of 20 (cm3x l), at a temperature of 350 ° C for 30 minutes. Subsequently, with the purpose of obtaining porosity in the precursor films and improve the crystalline quality of ZnO, after the first treatment they were annealed at 800 ° C for 1 hour in three different atmospheres, the first was N2 with a flow of 20 (cm3x l) (S1 ) , the second was air with a relative humidity of 42% (S2 ), finally the third atmosphere was dry air (nitrogen: oxygen = 70: 30) (S3 ), Aluminum interdigitated contacts were defined on the surface of the films by the lift-off photolithographic method. To evaluate the response of the device, it was placed inside a non-evacuated chamber of known volume and exposed to several different amounts of carbon monoxide. The concentrations used were 50, 100, 250, at different temperatures. The current produced through the sensor by a constant voltage was recorded as a function of the time while the atmosphere was periodically exchanged. The surface morphology of the samples changed according to the used oxidation atmosphere, featuring distinct uniform porous surfaces with nanosized diameters. The samples showed a uniform distribution of particles with a porosity generated after the complete sample oxidation with different size of porous (20nm-100nm), depending on the specific oxidizing atmosphere. The XRD patterns for the samples processed in dry N2 show preferential orientation in the plane (002) of the ZnO crystallites. Dry and wet air produced the wurtzite phase of ZnO according to the diffraction of the (100), (002), (101) planes as seen in Fig. 1. The sensing measurements were made for carbon monoxide. The results from the three samples are observed in Fig. 2, in which we can see that sample 3 shows a larger response. This can be attributed to the average pore size which turned to be 30 nm.

Reexamination of Nucleation and Growth Behavior of Zn during Zincating on Al: Role of Nitric Acid Etching

Deposition of various coatings on Al surface is required for variety of functional applications such as for better corrosion resistance, improvement in conductivity, wear resistance etc. These coatings are normally applied on Al surface followed by well-known zincating process (galvanic displacement) in order to obtain subsequent adherent overlayer coatings. Adhesion of these overlayers depends on uniformity of Zn films on Al surface and researchers normally follow either single zincating or double zincating process to eliminate oxide layer interference. However, it has been established over the years that double zincating is a better technique in comparison to single zincating to produce a uniform Zn-films on Al surface. It is to mention here that Al substrate undergoes nitric acid dip followed by single zincating prior to double zincating and is a very important step. A quiet good amount of research has already been devoted to obtain various adherent coatings on Al and Al-alloys and to analyze the nucleation mechanism during single and double zincating processes. However, the underline mechanism of nitric acid etching and its role on subsequent Zn-nucleation is yet to be fully understood. In view of this, in the present study, a systematic effort has been made to elucidate the role of nitric acid etching followed by single zincating on Zn nucleation and growth mechanism during subsequent second zincating. For this, we have studied the time-dependent zinc nucleation on 99.95% pure Al during single as well as double zincating. These Zn-nucleation and growth behavior on Al surface was monitored using AFM, FESEM and FIB-cut cross section image investigations in detail. Difference in nucleation and growth pattern of Zn on Al during two zincating processes was analyzed. Apart from these, the porous surface obtained after nitric acid dissolution was investigated in depth under AFM and FESEM along with EDS. Non-gravimetric method such as Rutherford Backscattering Spectrometry (RBS) was used to determine the deposition rate of Zn during competitive galvanic deposition of Zn and alkaline dissolution of Al while zincating. The Zn grain size obtained from AFM image was verified by GIXRD analysis. Open circuit potential (OCP) was monitored during single as well as double galvanic displacement processes to understand Zn nucleation behavior and correlated with the morphological data. The observed results will be discussed in terms of electrochemical processes involved, change in chemical nature of the Al surface and porous layer formation due to nitric acid etching and thermodynamic supersaturation on Zn nucleation. Figure 1

Formation of Zn Films by Magnetron Sputtering on Glass, Quartz and Silicon Substrates

Formation of Zn Films by Magnetron Sputtering on Glass, Quartz and Silicon Substrates

Growth and Characterization of Nanostructured Ag-ZnO for Application in Water Purification

In this work, a low-cost method to produce ZnO nanostructured materials for the treatment of water polluted with model organic pollutants (e.g. dyes) is presented. Zinc and silver-coated Zn (Ag/Zn) films, fabricated via sputtering method were naturally oxidized via a simple, low-temperature, scalable thermal process. During oxidation, Ag/ZnO nanorods were grown on Zn foils after treating their surface with various agents (e.g. acids) and annealing in an oven at temperatures 385-400 °C. The ZnO and Ag/ZnO films on Zn were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. The cationic dye Methylene Blue (MB) was selected as model pollutant dissolved in water, and a batch photo-reactor was fabricated and used to to study the adsorption capacity and photocatalytic performance of films. The transient varation of MB concentration in aqueous solutions was measured with UV-Vis spectroscopy. Ag/ZnO demonstrated a strong MB adsorbion capacity in dark conditions, and a satisfactory MB photocatalytic degradation under UV light irradiation.The optimized doping of Ag in Ag/ZnO film enhanced its photocatalytic activity, and seems well-promising for the potential scale-up of Ag/ZnO films, and use in large-scale systems for water purification under UV light irradiation.

In-depth analysis on Erbium co-doped CdO:Zn films deposited by nebulizer method for opto-electronic applications

In the present study, we have analyzed the fabrication of transparent conductive Erbium (Er) co-doped CdO:Zn films by nebulizer spray method (NSP) by adding different Er level from 0 to 1.5 wt%. X-ray diffraction (XRD) pattern confirmed polycrystalline behavior of prepared Er co-doped CdO:Zn films of cubic crystalline system. Surface roughness of the films was slightly decreased from 20 nm to 16 nm. Elemental mapping and energy dispersive analysis of X-ray (EDX) spectra confirm the existence of Cd, O, Zn and Er in 1.5 wt% Er co-doped CdO:Zn film surface. The estimated optical transmittance and band gap value enhanced from 2.62 to 2.96 eV on growing Er doping concentrations. Photoluminescence (PL) spectrum emitted one strong near-band-edge (NBE) emission at ∼ 435 nm for all the Er co-doped CdO:Zn films, signify their better optical quality. Hall Effect measurements evidenced that the Er co-doping provides enhancement on the carrier concentration and reduce the electrical resistivity. The quality factor of Er co-doped CdO:Zn film thin film was increased from 1.1 × 10−4 (Ω−1) to 11.0 × 10−4 (Ω−1) for increasing the Er doping concentration from 0 to 1.5 wt%.

Synthesis of Porous ZnO Films on Quartz Substrates by Thermal Oxidation and the Oxidant Atmosphere Effect

The synthesis and characterization of porous ZnO films using a two stage process by thermal oxidation using a bilayer precursor film (ZnO/Zn) consisting of a Zn film covered with a ZnO nanofilm formed on quartz substrates is reported. The Zn films of 50 nm were grown by DC sputtering method at 300K. In the first stage bilayer precursor films (BPF) of ZnO/Zn were produced by growing a ZnO nanofilm on Zn films by thermal oxidation at 350 °C by 30 min in N2 atmosphere containing 5 ppm of O2, and in the second stage the BPFs were oxidized at 800 °C for one hour either in dry N2, dry or wet air with 42% of humidity. The produced porous ZnO films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopy measurements. The results revealed the role of the oxygen content and the relevance of the humidity content in the processing atmosphere. When the BPF was oxidized in N2 with low oxygen content nanoporous ZnO films of wurtzite phase with its c-axis perpendicular to the plane of the substrate were produced. When rich oxygen content oxidation atmospheres were used, either in dry or wet air, nanoporous ZnO films with three main crystallite orientations (100), (002) and (101), were produced. The optical transmittance characteristics at the band edge region were strongly influenced by the humidity content but induce the formation of reproducible nanoporous ZnO films with sizes of ≈ 10 nm.

The effect of nanoscale biodegradable polymer film on the healing of cut wounds of the skin of complicated Psevdomonas auregenosa (Experimental research)

Introduction. Effect of the biodegradable polymer film saturated with zinc nanoxide and hydrated C60 fullerene on the healing of skin cut wounds complicated Pseudomonas aeruginosa are study.
 Materials and methods. The studies were performed on 35 Guinea pigs in vivarium of IvanoFrankivsk National Medical University.
 The animals were divided into three groups: group I (10 animals) the wounds were treated without the use of films; group II (10 animals) – the covering material for Curasorb Zn wounds was used; group III (10 animals) –the biodegradable polymer film with C60 fullerene and zinc nanoxide (nZnO – particle size of 30 nm) was used.
 The simulated skin cut wounds were infected with Pseudomonas aeruginosa and investigated wound healed at 3, 7, 14 and 21 days using a Curasorb Zn film and a biodegradable polymer film with C60 fullerene and zinc nanoxide. The area of the wounds was measured, the microbiological examination of the wound content and pathomorphological evaluation of the wound tissues.
 Results. Wounds area in animals of group II to the 3-rd day increased slightly by 8,9 mm2, and wounds area animals of group III decreased by 44,8 mm2, indicating the therapeutic effect and sorption capacity of the film from the first days of treatment.
 Curasorb Zn films reduced the bacterial pathogen by two orders and the nanooxide film reduced the bacterial level to non-pathogenic levels of magnitude by 3 orders of magnitude by day 3. The bacterial level remained high in the film-free group (group I).
 Conclusion. The polymer film saturated with zinc nanooxide and hydrated C60 fullerene has a high local wound healing effect, antimicrobial activity, which improves the effectiveness of local treatment of purulent wounds and reduce the healing time.

Excimer laser annealing method for achieving low electrical resistivity and high work function in transparent conductive amorphous In2O3:Zn films on a polyethylene terephthalate substrate

We have developed an excimer laser annealing method to achieve low electrical resistivity (ρ) and a high work function in amorphous In2O3:Zn (IZO) films on polyethylene terephthalate (PET) substrates. The effect of excimer laser irradiation of the films on crack formation, electrical properties (ρ, carrier concentration, and Hall mobility), and work function were investigated. KrF excimer laser irradiation produced cracks in the surface of the IZO films on PET as a result of thermal expansion of the PET substrate. By inserting an amorphous SiO2 layer as a heat barrier between the IZO layer and PET substrate, crack formation was prevented. Moreover, it was found that the work function of IZO film could be controlled by the laser fluence and repetition rate. Irradiation of a 150-nm-thick amorphous IZO film on a SiO2-coated PET substrate achieved a low ρ of 3.55 × 10−4 Ω cm and a high work function of 5.4 eV due to the reduction of oxygen and carbon while maintaining a flat surface.

Raman study of laser-induced formation of II–VI nanocrystals in zinc-doped As–S(Se) films

Zn-doped As2Se3 and As2S3 films were prepared by thermal evaporation. Their amorphous structure was confirmed by Raman spectroscopy. Zinc chalcogenide nanocrystals can be formed in the films under laser irradiation due to the photoenhanced diffusion of atoms in the arsenic chalcogenide films, which enables aggregation of Zn and S(Se) atoms in nanocrystals. For As2S3:Zn films, not only ZnS, but also ZnO crystallites can be formed under irradiation with UV laser light due to oxidation of the film surface with abundant zinc atoms.

Degradation of Human Serum Albumin by Infrared Free Electron Laser Enhanced by Inclusion of a Salen-Type Schiff Base Zn (II) Complex.

A salen-type Schiff base Zn(II) complex included in human serum albumin (HSA) protein was examined by UV-Vis, circular dichroism (CD), and fluorescence (PL) spectra. The formation of the composite material was also estimated by a GOLD program of ligand–protein docking simulation. A composite cast film of HSA and Zn(II) complex was prepared, and the effects of the docking of the metal complex on the degradation of protein molecules by mid-infrared free electron laser (IR-FEL) were investigated. The optimum wavelengths of IR-FEL irradiation to be used were based on experimental FT-IR spectra and vibrational analysis. Using TD-DFT results with 6-31G(d,p) and B3LYP, the IR spectrum of Zn(II) complex could be reasonably assigned. The respective wavelengths were 1652 cm−1 (HSA amide I), 1537 cm−1 (HSA amide II), and 1622 cm−1 (Zn(II) complex C=N). Degradation of HSA based on FT-IR microscope (IRM) analysis and protein secondary structure analysis program (IR-SSE) revealed that the composite material was degraded more than pure HSA or Zn(II) complex; the inclusion of Zn(II) complex enhanced destabilization of folding of HSA.