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Bioresorbable electrochemical sensors remain mostly unexplored despite their ability to provide continuous in situ measurements of critical biomarkers. The primary challenge arises from the direct exposure of the electrodes' thin metal films to biofluids, which poses difficulties in ensuring both proper operational lifetimes and sensing performance. Molybdenum (Mo) presents itself as a promising biometal due to its uniquely gradual dissolution in biofluids, facilitated by the formation of a slower‐dissolving MoOx surface layer. Consequently, carefully engineered MoOx films can endow transient electrochemical sensors with unparalleled stability during extended operational lifetimes. Herein an unprecedented sensor architecture achieved via the unique pairing of sputtered Mo and MoOx thin films, probed as a pH and dissolved oxygen sensor is reported. Compared to a bare Mo electrode, a bilayer Mo+MoOx electrode subjected to post‐deposition annealing (400 °C, 60 min, N2 environment) displayed a largely improved stability (>24 h) in solution and demonstrated predictable functionality during ongoing film dissolution at 37 °C. Collectively, this work establishes a pioneering strategy for the fabrication of reliable and clinically relevant implantable electrochemical sensors. [ABSTRACT FROM AUTHOR]

Green hydrogen has an audible echo in the clean energy field. In this piece of work, pure and Mo-doped CuO thin films were deposited at different substrate temperatures on the Indium Tin Oxide (ITO) by the DC/RF sputtering technique. The prepared samples were utilized to generate hydrogen gas within the photoelectrochemical water-splitting mechanism. Crystallographic planes (−111), and (200) were the preferred orientations for pure and Mo-doped CuO thin films. Moreover, the average crystallite size was doubled by Mo doping reaching 25.8 nm. FE-SEM microscopic image exhibits that the pure and Mo–CuO thin films have a regular distribution with a small size. The optical band gap has rosed by doping from 1.8 eV to 2.05 eV. Then, it increased to 2.3 eV and 2.4 eV at temperatures of 100 °C and 200 °C respectively. Pure and Mo–CuO thin films were applied as photocathodes for hydrogen generation with water water-splitting technique. The photoelectrochemical application revealed a photocurrent density of ∼2.25 mA/cm2 for Mo-doped CuO photoelectrode at room temperature. This optimum photoelectrode was studied for stability and electrochemical impedance. In addition, the incident photon to current efficiency (IPCE%) was 4.47 % at 500 nm. The applied bias photon to current conversion efficiency (ABPE%) was 4.25 % at −0.38V. As a result of the above, pure and Mo-doped CuO photoelectrodes are low-cost thin films and have a high-efficiency performance for green hydrogen generation industrially. • Mo-doped CuO thin films were carefully sputtered on an ITO substrate at different temperatures. • Effect of doping and temperature on structural and optical properties of CuO thin films has been studied. • The efficiency of Mo-doped CuO photoelectrode at room temperature outperforms the rest. • Photocurrent density ∼2.25 mA/cm2 and (ABPE%) 4.25 % at −0.38V were revealed. • Mo–CuO photoelectrodes have a high level performance for green hydrogen generation. [ABSTRACT FROM AUTHOR]

Challenges have arisen in selecting suitable candidates for interconnects and metal contacts due to the exponential increase in metal resistivity at scaled pitches. Molybdenum (Mo) has emerged as a promising alternative to the traditional metals such as copper or tungsten owing to its low electrical resistivity and electron mean free path. In this study, we investigated the formation of a molybdenum film grown by thermal atomic layer deposition (ALD) using a MoO2Cl2 solid precursor and H2 and NH3 gases as the reducing agents. A molybdenum nitride film served as the seed layer on a SiO2 substrate before molybdenum film deposition. The analysis focused on the film's phase, morphology, chemical bonding states, and resistivity across various thicknesses. X-ray diffraction (XRD) confirmed the presence of polycrystalline BCC planes. Our analyses confirmed the successful growth of the molybdenum metal thin film, which, at a thickness of 10 nm, exhibited a record-low resistivity of approximately 13 μΩ cm. [ABSTRACT FROM AUTHOR]

In this work, RF magnetron co‐sputtering was used to fabricate molybdenum oxytelluride thin films with different atomic ratios. Scanning electron micrographs and atomic force micrographs revealed that pure Mo thin films were segregated. Thin films with 40% Te content portrayed needle‐like structures and thus had the largest Rq value of 2.48 nm. Contact angle measurements further supported the findings as the thin films with 40% Te content were the most hydrophobic. X‐ray photoelectron spectroscopy results revealed that the major oxidation states of Mo from Te‐poor to Te‐rich TFs were changed from high (+6) to low (+4 and/or +2). X‐ray diffraction data showed that peaks pertaining to molybdenum oxide species appeared, notably at 33.048° and 33.115°. Ultraviolet photoelectron spectroscopy and Kelvin probe measurements evinced that the work function increases with increasing Te content. Four‐point probe measurements revealed that molybdenum oxytelluride thin films tend to have higher electrical conductivity than pure Mo and Te thin films. [ABSTRACT FROM AUTHOR]

We propose a simple approach to locally modify the conductance of molybdenum oxide thin films with thermal annealing in oxygen atmosphere at relatively low temperature for constructing a visible-blind ultraviolet photoconductor. The amorphous MoO x is grown by remote plasma enhanced atomic layer deposition (RPALD), and then crystallized into α -MoO x at 500 °C in argon atmosphere, which exhibits good conductance with resistivity of 3.9 × 10−3 Ω cm due to the formation of oxygen vacancies. Good ohmic contact between Ti and the crystallized MoO x is demonstrated with specific contact resistance of 9.74 × 10−4 Ω cm2. The lateral Au/Ti-MoO x -Ti/Au structures are defined and the conductance of the exposed MoO x channel is significantly modified by thermal annealing in oxygen atmosphere to form a photodetector, which shows obvious photoresponse at the wavelength of less than 372 nm with low dark current of 0.9 pA at 5 V, and the remarkable responsivity of 0.75 mA W−1 at 280 nm is achieved with a high ultravoilet/visible rejection ratio. The low dark current and incredible responsivity can be attributed to the good ohmic contacts of untreated MoO x and the reduction of number of oxygen vacancies in the MoO x channel. The key role of oxygen vacancy on the conductance of MoO x has been demonstrated. Those results suggest that the MoO x thin films are promising candidate for visible-blind ultraviolet photodetectors in a simple complementary metal oxide semiconductor (CMOS)-compatible process. [ABSTRACT FROM AUTHOR]

We present the fabrication of a MoS2−xSex thin film from a co-sputtering process using MoS2 and MoSe2 commercial targets with 99.9% purity. The sputtering of the MoS2 and MoSe2 was carried out using a straight and low-cost magnetron radio frequency sputtering recipe to achieve a MoS2−xSex phase with x = 1 and sharp interface formation as confirmed by Raman spectroscopy, time-of-flight secondary ion mass spectroscopy, and cross-sectional scanning electron microscopy. The sulfur and selenium atoms prefer to distribute randomly at the octahedral geometry of molybdenum inside the MoS2−xSex thin film, indicated by a blue shift in the A1g and E1g vibrational modes at 355 cm−1 and 255 cm−1, respectively. This work is complemented by computing the thermodynamic stability of a MoS2−xSex phase whereby density functional theory up to a maximum selenium concentration of 33.33 at.% in both a Janus-like and random distribution. Although the Janus-like and the random structures are in the same metastable state, the Janus-like structure is hindered by an energy barrier below selenium concentrations of 8 at.%. This research highlights the potential of transition metal dichalcogenides in mixed phases and the need for further exploration employing low-energy, large-scale methods to improve the materials' fabrication and target latent applications of such structures. [ABSTRACT FROM AUTHOR]

The trimanganese tetraoxide (Mn3O4) nanostructured thin films doped with 2 mol% of nickel (Ni) and molybdenum (Mo) ions were deposited by a simple electrophoretic deposition technique. The structural, optical, and morphological studies of these doped thin films were compared with pure Mn3O4 thin films. X-ray diffraction (XRD) confirmed the tetragonal Hausmannite spinel structure. The Fourier transform infrared spectroscopy (FTIR) provided information about the molecular composition of the thin films and the presence of specific chemical bonds. The optical study and band gap energy values of all thin films were evaluated by the UV-visible spectroscopy technique. The scanning electron microscopy (SEM) illustrated the morphological modifications of the Mn3O4 thin films due to doping of the nickel and molybdenum ions. The Brunauer Emmett Teller (BET) method has confirmed the mesoporous nanostructure and nanopores of the thin films. The supercapacitive performance of the thin films was studied by cyclic voltammetry (CV), and galvanostatic charge discharge (GCD) techniques using the threeelectrode arrangement. An aqueous 1M Na2SO4 electrolyte was used for the electrochemical study. The 2 mol% Ni-doped Mn3O4 thin film has shown maximum specific capacitance than pure and Mo-doped Mn3O4 thin films. Hence, this study proved the validity of the strategy - metal ion doping of Mn3O4 thin films to develop it as a potential candidate for electrode material in futuristic energy storage and transportation devices. [ABSTRACT FROM AUTHOR]

Thin films of transition metal oxides such as molybdenum oxide (MoOx) are attractive for application in silicon heterojunction solar cells for their potential to yield large short‐circuit current density. However, full control of electrical properties of thin MoOx layers must be mastered to obtain an efficient hole collector. Here, we show that the key to control the MoOx layer quality is the interface between the MoOx and the hydrogenated intrinsic amorphous silicon passivation layer underneath. By means of ab initio modelling, we demonstrate a dipole at such interface and study its minimization in terms of work function variation to enable high performance hole transport. We apply this knowledge to experimentally tailor the oxygen content in MoOx by plasma treatments (PTs). PTs act as a barrier to oxygen diffusion/reaction and result in optimal electrical properties of the MoOx hole collector. With this approach, we can thin down the MoOx thickness to 1.7 nm and demonstrate short‐circuit current density well above 40 mA/cm2 and a champion device exhibiting 23.83% conversion efficiency. [ABSTRACT FROM AUTHOR]

Thin film CdTe solar cells have been recognized as reliable alternative for the manufacture of cheap photovoltaic solar cells of the future, due to its excellent absorber characteristics and simple, low-cost manufacturability. However, for the attainment of higher cell performances, additional studies are needed to increase cell efficiency through further development of better quality films and new fabrication processes. In the substrate-structured CdTe thin film solar cells, the CdTe absorber layer is deposited directly onto the substrate or through a back contact layer. But the quality of deposited film is believed to depend on the type and smoothness of the substrate. In this work CdTe was deposited on different substrates by RF sputtering and the effects on the deposited films were studied in terms of their structural and morphological forms. The substrates used were: pure molybdenum sheets (Mo), molybdenum-sputtered on molybdenum (Mo/Mo), molybdenumsputtered polyimide (PI/Mo) and molybdenum-sputtered glass (glass/Mo). The characterization tools used included XRD, SEM and AFM. The results showed that all surfaces produced uniform, compact and pinhole-free films; however, those on smoother surfaces produced larger as-deposited grain sizes of up to1.7µm as against 1.3 for rougher surfaces. Non-uniformities such as overgrowth and voids were observed, but only films on PI showed evidence of cracking and peel-offs. [ABSTRACT FROM AUTHOR]

We investigated the impact of Gd magnetic impurities on the superconducting properties of disordered MoNx thin films grown by reactive co-sputtering at room temperature. The samples were fabricated in the two gun cluster using Mo and Gd targets in an Ar + N2 atmosphere with a total pressure of 0.67 Pa and a N2 concentration of 7%. The study focuses in thin films with thickness between 22 and 27 nm. We modified the chemical composition by varying the power of the Gd target from 0 to 24 W, fixing the Mo in 100 W. The chemical state of the samples was analysed using X-ray Photoelectron Spectroscopy. The samples primarily exhibit an amorphous metallic Mo and Gd nitride structure. With the addition of Gd, the superconducting critical temperature is suppressed, dropping from 7.4 K for pure MoNx to below 3 K for samples containing ≈ 4.5 at.% Gd. Furthermore, the temperature dependence of the upper critical field (Hc2) and the vortex dissipation mechanism are also affected. Specifically, Hc2(0) is reduced from 10 to 7.7 T for samples with 3.1 at.% Gd. Moreover, at a temperature of 3 K, there is an increase in the magnetic field dependence of the critical current density for low Gd doping. These alterations also impact the instability of the vortex lattice, limiting the maximum achievable vortex velocity during dissipation. [ABSTRACT FROM AUTHOR]

The next generation of photonics and nano-optical devices may be based on two-dimensional(2D) transition metal dichalcogenides (TMDs). In this research, molybdenum diselenide () nanosheets, as one important member of TMDs, have been synthesized by the solvothermal method and characterized through XRD patterns, SEM, and TEM images. Nanosheets were found to have a hexagonal phase based on XRD patterns and the crystallinity percentage is 24.8 %. The lattice constants of the hexagonal phase of are calculated as a= 3.08 ºA, c= 13.72 ºA. The calculated average value of the crystallite size, dislocation density, and micro strain are 21.935 nm, 2.138 nm-2 and 9.070, respectively. A few layers of nanosheets without wrinkles were observed on TEM and SEM. Next, the synthesized nanosheets were employed to prepare thin films with three different thicknesses using the spin coating method. By employing a continuous wave (CW) Nd : YAG laser at 532 nm via a Z-scan approach, this study investigates how thin film thickness affects the thermal nonlinear optical (NLO) responses of nanosheets. The magnitude of NLO coefficients of the prepared thin films decreased with increasing film thickness. It is observed that the prepared thin films possess saturable absorption (SA) as well as the self-focusing effect. Saturable absorbers and mode-locking devices can be developed with thin films because of their improved NLO properties. [ABSTRACT FROM AUTHOR]

Bulk acoustic wave (BAW) filters have been extensively used in consumer products for mobile communication systems due to their high performance and a standard CMOS compatible integration process. However, a traditional BAW filter generally presents only one frequency transmission band; hence, it cannot meet the demands of multi-mode wireless communication systems. In this work, we propose a radio frequency dual-band filter based on a dual-mode film bulk acoustic resonator (FBAR). The dual-mode FBAR consists of molybdenum electrodes and an aluminum nitride film with a c axis tilt angle, which leads to the coexistence of the longitudinal mode and the shear mode in the resonator. The influence of the tilt angle on the resonant frequency and electromechanical coupling coefficient of the dual-mode FBAR is investigated. Subsequently, the behaviors of the dual-mode FBAR have been emulated by a modified Butterworth–Van Dyke model with two motional branches, which is further used to design and optimize the dual-band filter. The dual-mode FBAR-based filters connected in a ladder configuration present two dual passbands of 43 MHz and 105 MHz, respectively. The developed filters with dual passbands can give an inspiration to the design of BAW devices in modern wireless communications. [ABSTRACT FROM AUTHOR]

The morphological, transport, and terahertz optical properties of DC magnetron-sputtered granular molybdenum thin films with nano-grains embedded in an amorphous molybdenum/molybdenum oxide matrix have been studied in their normal and superconducting states. The superconducting transition temperatures of these films are much higher than that of bulk molybdenum. The optical properties of these thin films have been studied using terahertz time-domain spectroscopy. Their properties have been compared with those of the existing materials used for the development of radiation detectors. The films' resistivity lies in the >100 μΩ cm range, ideal for making highly sensitive radiation detectors. Hall measurements indicate holes as the dominant carriers with very small mean free path and mobility. In the normal state, the films are disordered bad metals. However, they have a large superfluid density and stiffness in their superconducting state. The properties of the films in the normal and superconducting states are promising for their use in cryogenic radiation detectors for microwave, terahertz, and far-infrared frequency ranges. [ABSTRACT FROM AUTHOR]

We report a simple method involving optimization of oxygen partial pressure (OPP) in the after-growth annealing process of MoOx nanostructured thin films that results in a better field emitter with a low turn-on field and a high field enhancement factor. A ≈250 nm thick molybdenum oxide thin film has been synthesized on Si(100) substrates by the physical vapor deposition technique. The as-deposited thin films are annealed at 600 °C for 30 min in different OPPs, such as ≈2.1 × 10−9 Pa, ≈2.1 × 10−1 Pa, and ≈2.1 × 104 Pa. The effect of postannealing on the morphology, crystal structure, stoichiometry, elemental concentration, optical and local work function of the samples has been investigated using scanning electron microscopy, atomic force microscopy, resonant Rutherford backscattering spectrometry, and X-ray diffraction methods. As-deposited amorphous thin films transformed to granular MoO2 and layeredlike α-MoO3 nanostructures after annealing at 600 °C for 30 min in the OPP of ≈2.1 × 10−9 Pa and ≈2.1 × 104 Pa, respectively. The optical bandgap and the local work function are increased from 2.60 eV to 3.22 eV and 5.12 eV to 5.76 eV, whereas the field emission turn-on field is decreased from 6.6 V/μm to 4.7 V/μm for 10 μA/cm2 with increasing OPP from ≈2.1 × 10−9 Pa to ≈2.1 × 104 Pa. [ABSTRACT FROM AUTHOR]

Calcium-molybdate ultrathin films were prepared on a Mo(001) crystal and characterized by means of scanning tunneling microscopy (STM), electron diffraction, photoelectron spectroscopy, and density functional theory (DFT). The films were grown via reactive Ca deposition, followed by a vacuum annealing step to trigger Mo diffusion from the support into the Ca—O ad-layer. A series of crystalline oxide configurations was revealed that evolves from a (3 × 3) to a (4 × 4) and (6 × 6) superstructure with increasing annealing temperature and finally decays to a binary MoOx phase. The stoichiometry of the initial (3 × 3) phase was estimated to CaMo3O6, yet with decreasing Ca concentration at higher temperature. In the search for a suitable structure model for DFT calculations, we have started with a bulk CaMo5O8 configuration that was iteratively modified to match the experimental data. The optimized structure is made of regular sequences of flat-lying and upright standing Mo octahedrons, being separated from each other by Ca2+ ion rows. With decreasing Ca content, the central Mo units grow in size, which explains the observed transition from (3 × 3) to (6 × 6) superstructures upon annealing. The proposed structure model rationalizes the periodicity and corrugation of the regular oxide surface as well as the characteristic domain patterns in the film. Its electronic properties, as deduced from STM conductance spectroscopy, can be correlated with an increasing metallicity of the ad-layer upon annealing. Our work presents a facile pathway to produce high-quality ternary oxide films via interdiffusion of atoms from a suitable metal support into a binary oxide layer. [ABSTRACT FROM AUTHOR]

In this study, we conducted research on manufacturing molybdenum (Mo) thin films by a thermal atomic layer deposition method using solid MoO2Cl2 as a precursor. Mo thin films are widely used as gate electrodes and electrodes in metal-oxide semiconductor field-effect transistors. Tungsten (W) has primarily been used as a conventional gate electrode, but it suffers from reduced resistivity due to the residual fluorine component generated from the deposition process. Thus, herein, we developed a Mo thin film with low resistivity that can substitute W. The MoO2Cl2 precursor used to deposit the Mo thin film exists in a solid state. For solid precursors, the vapor pressure does not remain constant compared to that of liquid precursors, thereby making it difficult to set process conditions. Furthermore, the use of solid precursors at temperatures 600 °C and above has many limitations. Herein, H2 was used as the reactive gas for the deposition of Mo thin films, and the deposition temperature was increased to 650 °C, which was the maximum processing temperature of the aluminum nitride heater. Additionally, deposition rate, resistivity change, and surface morphology characteristics were compared. While resistivity decreased to 12.9 μΩ∙cm with the increase of deposition temperature from 600 °C to 650 °C, surface roughness (Rq) was increased to 0.560 nm with step coverage of 97%. X-ray diffraction analysis confirmed the crystallization change in the Mo thin film with increasing process temperature, and a certain thickness of the seed layer was required for nucleation on the initial wafer of the Mo thin film. Thus, the molybdenum nitride thin film was deposited after the 4 nm deposition of Mo thin film. This study confirmed that crystallinity of Mo thin films must be increased to reduce their resistivity and that a seed layer for initial nucleation is required. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) thin film/molybdenum (Mo) electrode structures are typically required in microelectromechanical system applications. However, the growth of highly crystalline and c-axis-oriented AlN thin films on Mo electrodes remains challenging. In this study, we demonstrate the epitaxial growth of AlN thin films on Mo electrode/sapphire (0001) substrates and examine the structural characteristics of Mo thin films to determine the reason contributing to the epitaxial growth of AlN thin films on Mo thin films formed on sapphire. Two differently oriented crystals are obtained from Mo thin films grown on sapphire substrates: (110)- and (111)-oriented crystals. The dominant (111)-oriented crystals are single-domain, and the recessive (110)-oriented crystals comprise three in-plane domains rotated by 120° with respect to each other. The highly ordered Mo thin films formed on sapphire substrates serve as templates for the epitaxial growth by transferring the crystallographic information of the sapphire substrates to the AlN thin films. Consequently, the out-of-plane and in-plane orientation relationships among the AlN thin films, Mo thin films, and sapphire substrates are successfully defined. [ABSTRACT FROM AUTHOR]

This work studied the growth of molybdenum oxide thin films with thermal atomic layer deposition (ALD) using Mo(iPrCp)2H2 and O3 as precursors. Growth parameters were determined by varying growth temperature and precursor dose times. ALD growth was exhibited in a temperature range of 100–200 °C. The growth per cycle ranged from 1.3 to 1.7 Å/cycle with a standard uniformity parameter of <5%. Attempts to grow films using H2O as an oxygen source showed no significant growth. Film properties were measured using spectroscopic ellipsometry, x-ray reflectivity, x-ray diffraction, x-ray photoelectron spectroscopy, and infrared spectroscopy. [ABSTRACT FROM AUTHOR]

A systematic experimental study was performed to determine laser irradiation conditions for the large-area fabrication of highly regular laser-induced periodic surface structures (HR-LIPSS) on a 220 nm thick Mo film deposited on fused silica. The LIPSS were fabricated by scanning a linearly polarized, spatially Gaussian laser beam at 1030 nm wavelength and 1.4 ps pulse duration over the sample surface at 1 kHz repetition rate. Scanning electron microscope images of the produced structures were analyzed using the criterion of the dispersion of the LIPSS orientation angle (DLOA). Favorable conditions, in terms of laser fluence and beam scanning overlaps, were identified for achieving DLOA values <10 ∘ . To gain insight into the material behavior under these irradiation conditions, a theoretical analysis of the film heating was performed, and surface plasmon polariton excitation is discussed. A possible effect of the film dewetting from the dielectric substrate is deliberated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Films on electropolished substrates have higher absorbances and are more homogeneous. • By combining absorbance and emittance, passivation results in greater solar selectivity. • SiO 2 deposition on Mo films increased their absorbances. • The SiO 2 layer increased the surface roughness of the coatings. • The SiO 2 layer improved the surface homogenization of the films. The thermal performance of solar collectors depends on the selective coverage over their absorbing plate, known as selective surfaces, which determines the heat gain and loss of the equipment. Different materials and layering arrangements can be used for the production of selective surfaces. This work proposes the production of selective surfaces of molybdenum (Mo) and silica (SiO 2) evaluating the influence of the type of substrate treatment (chemical cleaning, passivation and electropolishing) on this performance. The results obtained in UV–Visible and Near Infrared Spectrophotometry showed that the surface absorptance is higher for Mo and Mo/SiO 2 films on electropolished surfaces compared to treatments with acid and hexane. The highest absorptance reached was 98.10% for a Mo/SiO 2 film (45.023 nm), on electropolished substrate. However, the highest solar selectivity was obtained from the Mo/SiO 2 film on a passivated substrate. X-ray diffraction (XRD) exhibited peaks characteristic of the metallic Mo phase, and the presence of silica in the amorphous and crystalline phases in the form of quartz was also verified. The results obtained in Optical Profilometry and Atomic Force Microscopy (AFM) indicate that the absorptance of the samples is influenced by the roughness of the substrates. [ABSTRACT FROM AUTHOR]

During the present work, molybdenum trioxide (MoO3)-doped vanadium pentaoxide (V2O5) thin films of different concentrations (4 wt%, 6 wt%, and 8 wt%) at two different thicknesses are deposited by standard thermal evaporation method on a glass substrate. Fourier transform infrared study and field-emission scanning electron microscopy are employed for structural and surface morphology characterization. The effects of thickness and concentration on the surface morphology and optical switching properties of the films are studied comprehensively. The optical switching behavior of molybdenum trioxide-doped vanadium pentaoxide (MoO3:V2O5) thin films is reported by using a Fabry–Perot cavity at the second harmonic wavelength (532 nm) of nanosecond Nd:YAG laser. The optical nonlinear parameters, viz. nonlinear refractive index (n2) and cubic susceptibility (χ3), of the material are obtained from optical switching characteristics. Optical switching action based on Kerr effect with a minimum recovery time of 5 ms is reported. [ABSTRACT FROM AUTHOR]

This study intends to analyze the effect of annealing temperature on the various characteristics of pure molybdenum trioxide (MoO3). For this purpose, nanoparticles of molybdenum trioxide (MoO3) were synthesized by hydrothermal technique and fabricated into thin films using a spin coater. The obtained films were annealed at 400 °C, 500 °C, and 600 °C. Their structural, morphological, electrical, and optical properties were investigated as a function of annealing temperatures. These films were also used as liquefied petroleum gas and humidity sensors. The X-ray diffraction (XRD) analysis confirmed the crystallinity and orthorhombic structure of the films. The field emission scanning electron microscope (FE-SEM) showed the morphology of the synthesized films. Atomic force microscopy (AFM) showed that the thin films annealed at 600 °C were rougher than the films annealed at other temperatures. The optical band gap was estimated using UV–visible spectroscopy, and the bandgap was observed to decrease slightly with the increase in annealing temperature. At room temperature, the thin film annealed at 600 °C showed a maximum sensing response of 59.78% to 2.0 vol% of liquefied petroleum gas and a sensitivity of 24.8025 MΩ/%RH to the humidity. [ABSTRACT FROM AUTHOR]

The effect of Mo thin film deposition power in DC sputtering on the formation of a MoSe2 interfacial layer grown via the annealing of CIGSe/Mo precursors in an Se-free atmosphere was investigated. A Mo layer was deposited on glass substrates using the DC magnetron sputtering method. Its electrical resistivity, as well as its morphological, structural, and adhesion characteristics, were analyzed regarding the deposition power. In the case of thinner films of about 300 nm deposited at 80 W, smaller grains and a lower volume percentage of grain boundaries were found, compared to 510 nm thick film with larger agglomerates obtained at 140 W DC power. By increasing the deposition power, in contrast, the conductivity of the Mo film significantly improved with lowest sheet resistance of 0.353 Ω/square for the sample deposited at 140 W. Both structural and Raman spectroscopy outputs confirmed the pronounced formation of MoSe2, resulting from Mo films with predominant (110) orientated planes. Sputtered Mo films deposited at 140 W power improved Mo crystals and the growth of MoSe2 layers with a preferential (103) orientation upon the Se-free annealing. With a more porous Mo surface structure for the sample deposited at higher power, a larger contact area developed between the Mo films and the Se compound was found from the CIGSe film deposited on top of the Mo, favoring the formation of MoSe2. The CIGSe/Mo hetero-contact, including the MoSe2 layer with controlled thickness, is not Schottky-type, but a favourable ohmic-type, as evaluated by the dark I-V measurement at room temperature (RT). These findings support the significance of regulating the thickness of the unintentional MoSe2 layer growth, which is attainable by controlling the Mo deposition power. Furthermore, while the adhesion between the CIGSe absorber layer and the Mo remains intact, the resistance of final devices with the Ni/CIGSe/Mo structure was found to be directly linked to the MoSe2 thickness. Consequently, it addresses the importance of MoSe2 structural properties for improved CIGSe solar cell performance and stability. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy was used to study the direct synthesis of strontium and molybdenum oxide thin films deposited by multitarget reactive magnetron sputtering (MT-RMS). Sr and Mo targets with a purity of 99.9% and 99.5%, respectively, were co-sputtered in an argon–oxygen gas mixture. The chamber was provided with an oxygen background flow plus an additional controlled oxygen supply to each of the targets. We demonstrate that variation in the power applied to the Mo target during MT-RMS enables the production of strontium and molybdenum oxide films with variable concentrations of Mo atoms. Both molybdenum and strontium were found in the oxidized state, and no metallic peaks were detected. The deconvoluted high-resolution XPS spectra of molybdenum revealed the presence of several Mo 3d peaks, which indicates molybdenum bonds in a lower valence state. Contrary to the Mo spectra, the high-resolution strontium Sr 3d spectra for the same samples were very similar, and no additional peaks were detected. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) contain more than five alloying elements in a composition range of 5–35% and with slight atomic size variation. Recent narrative studies on HEA thin films and their synthesis through deposition techniques such as sputtering have highlighted the need for determining the corrosion behaviors of such alloys used as biomaterials, for example, in implants. Coatings composed of biocompatible elements such as titanium, cobalt, chrome, nickel, and molybdenum at the nominal composition of Co30Cr20Ni20Mo20Ti10 were synthesized by means of high-vacuum radiofrequency magnetron (HVRF) sputtering. In scanning electron microscopy (SEM) analysis, the coating samples deposited with higher ion densities were thicker than those deposited with lower ion densities (thin films). The X-ray diffraction (XRD) results of the thin films heat treated at higher temperatures, i.e., 600 and 800 °C, revealed a low degree of crystallinity. In thicker coatings and samples without heat treatment, the XRD peaks were amorphous. The samples coated at lower ion densities, i.e., 20 µAcm−2, and not subjected to heat treatment yielded superior results in terms of corrosion and biocompatibility among all the samples. Heat treatment at higher temperatures led to alloy oxidation, thus compromising the corrosion property of the deposited coatings. [ABSTRACT FROM AUTHOR]

We report on the thickness scaling behavior of ferroelectric Sc0.3Al0.7N (ScAlN) films grown on Mo substrates by molecular beam epitaxy. Switchable ferroelectricity is confirmed in ScAlN films with thicknesses ranging from 100 to 5 nm. An increase in coercive field and a significant diminution of remnant polarization are found when the ferroelectric layer is scaled down to below 20 nm. Notably, a switching voltage of 2–3.8 V and saturated remnant polarization of ∼23 μC/cm2 are measured in 5 nm thick ScAlN. X-ray diffractions and transmission electron microscopy studies indicate that the increase in coercive field and diminishment in switchable polarization can be closely linked to the surface oxidation and strain state in ultrathin ScAlN films. This work sheds light on the fundamental thickness scaling fingerprints of ScAlN thin films and represents an important step for next-generation compact and power-efficient devices and applications based on nitride ferroelectrics. [ABSTRACT FROM AUTHOR]

Vanadium oxide–molybdenum oxide (VO–MO) composite thin films with a thickness of 500 nm were fabricated by thermal evaporation method on a quartz substrate with different compositions of vanadium oxide and molybdenum oxide (VO75% MO25%, VO50% MO50% and VO25% MO75%). The crystallite size in the prepared VO–MO thin films was found to be around 21–30 nm in size. The VO–MO films showed good crystalline nature (phase of vanadium oxide VO2 along with MoO3). The fabricated composite thin films showed photochromic properties when exposed to sunlight. The thin films possessed multicolorism under sunlight irradiation. The fabricated films showed good reversible property on bleaching. The hydrophilic nature of VO–MO composite thin films was also studied. The thin films were characterized by XRD, XPS and AFM. Transmission spectra of the thin films after sunlight irradiation confirmed that the prepared thin films have an excellent photochromic property with remarkable reversibility. Surface wettability property of the prepared VO–MO thin films was studied by using water contact angle measurements. Thin film with VO50% MO50% composition showed better photochromic and hydrophilic properties. [ABSTRACT FROM AUTHOR]

With the increase in integration and the layers of superconducting electronics circuits, molybdenum (Mo)-based films become attractive resistive and inductive functional components because of the large kinetic inductance with the deep magnetic field penetration depth. A DC magnetron sputtering technology is used to fabricate Mo and MoNx films. The effects of different deposition conditions on the electrical properties, topography and crystal structure of the films are investigated. For the Mo films, the resistivity and the surface roughness decrease to 193 nΩ m and 0.72 nm, respectively, as the sputtering power increases and the sputtering pressure is reduced. The dominant (110) peaks of the X-ray diffraction pattern show a blueshift, and the full width at half maximum decreases with the rising sputtering powers. For the MoNx films, the superconducting transition temperature firstly rises and then lowers as the ratio of N2/Ar ratio increases. The physical properties of the Mo and MoNx films change with the sputtering process, and suitable deposition conditions can be selected for the different application structures in the superconducting electronics circuits. [ABSTRACT FROM AUTHOR]

In this work, the effects of the DC sputter conditions on the microstructure, morphology, topography, and adhesion of molybdenum (Mo) thin films deposited over graphite were analyzed. The sputtering power was varied in the 100–400 W range. Likewise, the working gas pressure was varied in the 1–4 Pa range. Different analytical techniques i.e., scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and Hall's effect were employed for characterizing the Mo/graphite coupons. The crystallite size was found to increase with the increase in the deposition rate as a result of the increase in the sputter power. The residual stresses in the films shift from compressive to tensile with increasing the working gas pressure. Similarly, the surface roughness was also found to increase with the increase in the working gas pressure. Moreover, all Mo thin films showed excellent adhesion as no delamination in any film was observed after adhesion test. Our findings suggest that the high-quality Mo film with dense pack structure and high crystallinity was achieved at moderate working gas pressure and high sputtering powers. [ABSTRACT FROM AUTHOR]

Summary: The combined features of functional electronic devices have attracted significant attention because of high demand for promising energy technologies. Of particular interest are electrochromic (EC) supercapacitors, which can visually display the level of stored energy in real‐time. Here, we demonstrate the EC energy storage properties of pure and doped Prussian blue (PB) thin films fabricated using electrodeposition. The pure PB films produced various colours at different potentials during their charging‐discharging cycles, but they suffered from instability. To overcome this, we doped PB films with ruthenium (Ru), iridium (Ir), and molybdenum (Mo). Of the doped specimens, the Mo‐doped PB films exhibited the most promising EC energy storage properties, with a specific capacity of 399.7 F g−1 at 1 A g−1, a colouration efficiency of 110.2 cm2 C−1, and an excellent optical density difference of 0.92. The Mo‐doped PB films also demonstrated ultra‐fast colouration and bleaching behaviour within 3.25 and 4.04 seconds, respectively. Our experimental findings suggest that Metal‐doped PB films can be employed for practical application. [ABSTRACT FROM AUTHOR]

Leakage current properties of pure and Mo-doped BiFeO' (BFO) thin films have been studied in order to identify the cause of high leakage currents. Interestingly, it was observed that the leakage current density reduced by more than two orders of magnitude upon Mo doping at Fe site of BFO. According to J-V characteristics, the leakage current density decreased from 1.101 × 10-6 A/cm2 to 9.4 × 10-8 A/cm2 at an applied bias voltage of 2.75 V with Mo substitution. These findings suggest that oxygen vacancies, rather than Fe2+ ions, are the primary cause of BFO's high conductivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Study of native surface oxidation of DC- sputtered Mo thin film. • Guideline of Mo thin film for storage and transportation in tropical environment. • Mo thin film kept in open air at room temperature undergoes surface oxidation. • Random growth of nanostructured MoO x. • MoO x has less conductivity compared to Mo as sputtered film. Molybdenum (Mo) is a versatile refractory metal that has been widely used as back contact in thin film photovoltaic cells. However, Mo tends to react with oxygen in ambient environment which influences its original properties. In this study, Mo thin films were stored in different environments (in vacuum desiccator and open air) for 8760 h. Subsequently, these films were characterized and analyzed by Grazing Incidence X-Ray Diffractometer (GIXRD), Raman spectroscopy, Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (FESEM-EDX), Conductive Atomic Force Microscopy (C-AFM), and Hall Effect measurement system. It was found that Mo thin film kept in open air at room temperature undergoes surface oxidation which results in random growth of nanostructured MoO x. Formation of these observed oxide compounds on the surface is correlated with decrement in the electrical conductivity mainly through lower carrier mobility. Preliminary results highlighted from this study can serve as general guideline for handling, storage and transportation requirements forMo thin film in tropical environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molybdenum (Mo) thin films were grown on AlN by pulsed laser deposition for heat sink applications. • Smooth and crystalline Mo films were obtained at 600 ˚C and 10 mTorr of Argon gas. • Thermal diffusivity was measured by photo-thermal surface displacement using an IR laser. • Under optimal deposition conditions, a thermal diffusivity very close to that of bulk Mo was obtained. • The Mo-AlN system was found to be stable up to an operating temperature of 200 °C. Thin films of molybdenum (Mo) were grown on aluminium nitride (AlN) substrates by pulsed laser deposition for heat sink applications. The effect of experimental growth parameters on the films' structural properties were investigated by Scanning Electron Microscopy, X-Ray Diffraction and Atomic Force Microscopy. Thermal characterization was achieved by measuring the in-plane thermal diffusivity of the grown layers by means of a photothermal beam deflection technique using an IR heating laser. Within the experimental parameters studied in this work, a substrate temperature of 600 ˚C and an ambient argon gas pressure of 10 mTorr were identified as the optimal growth conditions for the synthesis of smooth and well-crystallized Mo layers. Concurrently, the thermal diffusivity of the films is significantly affected by film growth parameters. Under the optimal growth conditions, a thermal diffusivity value as high as 5.42x10-5 m2/s was measured, a value that is very close to that of bulk Mo, and which would be a result of the synthesis of polycrystalline Mo films whose grains' size is greater than the heat carriers mean free path, namely the free electrons. The temperature dependence of the thermal diffusivity was also investigated, and the films were found to be stable up to an operating temperature of 200 °C. Beyond this temperature, photothermal beam deflection imaging shows the onset of film delamination from the underlying substrate. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to produce cobalt oxide (Co 3 O 4) thin films with improved optical, electrical, and electrochemical properties for device applications with a simple and low-cost method. Mo, W, and dual Mo and W at the ratio 10 wt% of Co 3 O 4 were added into the solutions. The prepared solutions were coated on glass substrates by spin coating method. The produced thin films' structural, morphological, optical, electrical, and electrochemical properties were examined. As a result of doping, the optical, morphological, conductivity, and electrochemical properties of Co 3 O 4 thin films improved and more stable structures were formed. The Mo and W co-doping provided the most improvement in the properties of the Co 3 O 4 thin film. The results obtained showed that the Mo and W co-doped Co 3 O 4 thin film is a potential candidate for highly efficient electrochemical applications. [ABSTRACT FROM AUTHOR]

The sustainable development of catalysts with Pt-like catalytic activity to produce hydrogen economically from water electrolysis is essential and challenging. Herein, we have prepared a novel catalyst with the combined virtues of nanocolumn structures and heterojunctions by magnetron sputtering molybdenum nitride (Mo 2 N) thin films over cobalt-metal-organic framework (Co-MOF) nanocolumns on carbon paper (CP), and explored the catalytic activities in hydrogen evolution reaction (HER). By optimizing the preparation process, the heterostructured Co-MOF@Mo 2 N/CP catalysts can exhibit an excellent HER performance with an overpotential of only 72.8 mV at 10 mA cm−2 and cycling durability over 24 h and 5000 cycles, achieving one of the best performances among state-of-the-art Mo-based catalysts. This work guides and accelerates the design of low-cost and high-performance transition metal nitrides HER catalysts for industrial applications. • Heterostructured Co-MOF@Mo 2 N/CP nanocolumns were fabricated by self-assembly and magnetron sputtering. • Effects of reaction and sputtering times on microstructure and HER properties were studied. • Co-MOF@Mo 2 N/CP catalyst exhibits excellent HER activity and durability. [ABSTRACT FROM AUTHOR]

Tetrakis(dithiocarboxylato)molybdenum(IV) complexes of the type Mo(S2CR)4 (R = Me, Et, iPr, Ph) were synthesized, characterized, and prescreened as precursors for aerosol assisted chemical vapor deposition (AACVD) of MoS2 thin films. The thermal behavior of the complexes as determined by TGA and GC-MS was appropriate for AACVD, although the complexes were not sufficiently volatile for conventional CVD bubbler systems. Thin films of MoS2 were grown by AACVD at 500 °C from solutions of Mo(S2CMe)4 in toluene. The films were characterized by GIXRD diffraction patterns which correspond to a 2H-MoS2 structure in the deposited film. Mo–S bonding in 2H-MoS2 was further confirmed by XPS and EDS. The film morphology, vertically oriented structure, and thickness (2.54 μm) were evaluated by FE-SEM. The Raman E12g and A1g vibrational modes of crystalline 2H-MoS2 were observed. These results demonstrate the use of dithiocarboxylato ligands for the chemical vapor deposition of metal sulfides. [ABSTRACT FROM AUTHOR]

This work was motivated by the promising physiochemical properties and catalytic activity of molybdenum carbide. Thin films of molybdenum carbide were deposited on the mono-crystalline cubic Si (400) substrate by utilizing a 3.6 kJ dense plasma focus device (Mather-type) with multiple shots. The structure of the films was examined by X-ray diffraction (XRD). XRD results indicated the absence of crystalline film for 5 focus shots, while for increased numbers of focus shots, the emergence of Mo-C peaks in the orientations (120), (014) and (232) confirmed the formation of orthorhombic β-Mo2C polycrystalline films. Moreover, a small variation in the crystallite size was observed by increasing the number of focus shots. The presence of molybdenum and carbon was confirmed by energy-dispersive X-ray (EDX) analysis. Surface morphology was studied under scanning electron microscope (SEM). SEM micrographs revealed non-uniform films with some surface defects such as cracks and craters of micron size, and rough surface. Revealed by the ellipsometry technique, the film thickness increased by increasing the number of focus shots. The electric conductivity, measured by the four-point probe technique, was the highest for 10 focus shots. However, the films have some structural defects, low conductivity and impurities like silicon and silicon carbide, but it was the first ever successful attempt to deposit molybdenum-carbide (Mo2C) thin films using the dense plasma focus device. [ABSTRACT FROM AUTHOR]

Cobalt-Molybdenum-Tungsten (CoMoW) alloy thin films were prepared through an induced electroplating route from a citrate bath on the surface of the copper electrode at the controlled value of pH 8. The CoMoW thin films have been prepared by varying the Mo concentrations like 0.1, 0.2, 0.3 and 0.4 M at a deposition time of 30 minutes over a plating current potential of 40 mA / cm2. The electrodeposited CoMoW coatings have been investigated with the help of Field Emission Scanning Electron Microscopy (FESEM), powder crystal X-ray diffraction (XRD), Electrochemical studies (impedance and polarization) and Vibrating Sample Magnetometer (VSM) to reveal its respective microstructure-based information, mechanical and soft magnetic nature of the synthesized CoMoW thin layers. The CoMoW thin films of an HCP crystal structure have been attained. The induced electroplated condition such as Mo concentration has a significant impact on the crystal structure system, surface morphology, and soft magnetic performances. The crystalline size of the CoMoW thin layers has varied from 22.66 nm to 42.87 nm. The synthesized CoMoW thin layers were smooth, without cracks and had uniform morphology. All the electroplated CoMoW films have the highest Co content along with low Mo content (Co content gradually decreased while increasing the Mo content in the deposits) and thickness varied from 10 to 20 µm. Through the electrochemical investigation studies, it is concluded that the corrosion rate of CoMoW thin films was slightly increased by increasing the Mo content and the corrosion resistance varied from 80.2 KO to 92.7 KO. The CoMoW thin alloy films with higher Co content exhibited a lower coercivity value of 3.69 Oe and the saturation magnetization of 49.049 emu/cm². [ABSTRACT FROM AUTHOR]

We investigated the structural, optical, and electrical properties of molybdenum and zirconium-doped zinc oxide (ZZO) with a purity of 99.99% deposited on a glass substrate by radio-frequency magnetron sputtering and annealed at different temperatures. The doping amount of zirconium on ZnO was 3 wt%. The optimal resistivity of the multilayers, 5.1 x 10-3 Q-cm, was observed for an annealing temperature of 400 °C. This film also had the highest transmittance of 93%. Moreover, the optimal figure of merit, 4.6 x 10-6 Ω-1, was observed for an annealing temperature of 400 °C. Furthermore, the grain size also increased with the annealing temperature, as observed by scanning electron microscopy. Mo/ZZO multilayer thin films with such excellent optical and electrical properties can be applied in photosensors. [ABSTRACT FROM AUTHOR]

Atomically thin molybdenum disulfide (MoS2) thin films are a promising avenue of investigation due to its potential applications in modern nanoscale electronic devices. In this work, we present a systematic investigation of the effect of in situ argon-ion sputter etching on the core-level X-ray photoelectron spectroscopy (XPS) of the chemical vapor-deposited MoS2 thin films. Raman spectroscopy of the MoS2 reveals that the thin films are tri-layer samples. Photoluminescence spectrum of the tri-layer MoS2 consists of A- and B-exciton emission peaks at 1.85 and 1.99 eV, respectively. The core-level XPS spectra of the Mo-3d and S-2p levels of the tri-layer MoS2 were investigated for various in situ sputter etch time. The as-grown and 6 s sputter-etched MoS2 sample exhibited Mo-3d spin–orbit doublets corresponding to + 4 oxidation state of Mo. For the sputter etch time beyond 40 s, the sample exhibited + 6 oxidation states of molybdenum suggesting the presence of thin molybdenum oxide at the interface between MoS2 and sapphire. We have also observed mid oxidation states like Mo5+, which is attributed to the argon-ion sputter etch-induced sulfur-deficient mixed S–Mo–O and sub-stoichiometric phases. [ABSTRACT FROM AUTHOR]

[Display omitted] • The molybdenum oxynitride (MNO) thin films were prepared by a novel magnetron sputtering methods. • The deposited MNO thin films can be assembled in battery directly without non-conductive binders. • The MNO thin films show promising conductivity and superior electrochemical performance. • The Mo 2 N can effectively improve the electron transfer and ion diffusion in the MNO thin films electrode. With the fast development of flexible wearable electronics, mobile electronic equipment, electric tool and electric vehicles, high specific capacity, superior cycle stability and excellent fast-charge performance are required for lithium-ion batteries (LIBs). Nevertheless, commercial graphite with the limited theoretical capacity (372 mAh g−1) and short lifespan is difficult to satisfy the requirements of the new generation of LIBs. In this work, the three-dimensional flexible molybdenum oxynitride (MNO) thin films with non-binder were prepared by magnetron sputtering approach. The charge transfer resistance and Li-ion diffusion coefficient were measured by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and the results show that molybdenum nitride is helpful to increase the diffusion and electron transfer of Li-ion. The MNO thin film annealed at 300 °C with irregular aggregate matrix structure shows a discharge capacity of 413 mAh g−1 after 180 cycles at 1 A g−1. The outstanding rate performance and cycle stability suggest that these binder-free thin film electrodes, especially nitrides, offer great opportunity for energy storage systems with fast-charge capabilities. [ABSTRACT FROM AUTHOR]

We present a methodology for numerically evaluating grain boundary scattering in polycrystalline molybdenum (Mo) thin films. Two types of Mo films (an epitaxially grown (110)-single-crystal film and a <110>-fiber-textured polycrystalline thin film) were sputter-deposited under identical conditions on a lattice-matched (11 2 ‾ 0) -Al 2 O 3 substrate and an amorphous glass substrate, respectively. This indicates equal background scattering (phonon and impurity scattering) for the two types. Further, the selected film thickness (236 nm) significantly exceeds Mo's inherent electron mean free path (11.2 nm), rendering surface scattering contributions negligible. The resistivity difference is therefore attributed to the grain boundary scattering. Using the Mayadas–Shatzkes model and an average grain size of 80.9 ± 2.8 nm (measured from a statistically significant number of grains (747)), the grain-boundary reflection coefficient for Mo films was determined to be 0.48 nm. The presented methodology, not limited to Mo, is expected to serve as a reliable analytical approach for advanced interconnects. • Developed a methodology to evaluate the grain boundary scattering in Mo films. • Assessed the resistivity contribution of grain-boundary electron scattering. • Used a statistically significant grain number for scattering analyses. • Used the Mayadas–Shatzkes model for the grain boundary reflection coefficient. [ABSTRACT FROM AUTHOR]

In this research, MoO3 and MoS2-WS2 thin films were prepared on glass substrates by spray pyrolysis. The effect of tungsten (W), spray solution rate, and annealing at T = 450 °C under sulfuration on the structural, morphological, optical, and photoconductive properties of films has been investigated. The tungsten to molybdenum atomic concentration ratio of x = [W/Mo] was varied from 0 to 0.3 in the spray solution. The structural analysis by X-Ray diffraction technique indicated the formation of the single phase of MoS2 and both phases of MoS2 and WS2 in pure and MoS2: W films, respectively. Optical gap changes of the MoS2-WS2 thin films were studied by changing the sulfur and tungsten concentration. The optical band gap of the films was obtained in the range of 1.76–2.02 eV and 1.41–1.68 eV, for MoS2 and WS2 phases, respectively. The photo-response studies showed that the spray rate and concentrations of sulfur (S) and tungsten (W), play an important role in the sensitivity factor. This method can be used for energy gap modulation for optoelectronic devise applications. [ABSTRACT FROM AUTHOR]

The photovoltaic performance of CZTS film solar cells grown via electrodeposition and sulfurization was investigated using citrate (acidic electrolyte) or potassium pyrophosphate (alkaline electrolyte)-based electrolytes to investigate the influence of deposition on the final layer quality. The desired composition of Zn-rich and Cu-poor compact layers were obtained from both of the electrolytes, with 1–3.5 at.% standard deviation over 2 cm2 Mo foils. The precursors were transformed into CZTS after sulfurization at 500 °C for 1 h. The standard deviation of the metals decreased to 0.9–1.4 at.% after sulfurization. The major phase volume of the film is CZTS, with some binary sulfide and ternary tin sulfide secondary phases, according to XRD and Raman spectroscopy analyses. CZTS absorber layer films on flexible Mo foil were manufactured in solar cells with the following architecture: Al:Ni/ITO/ZnO/CdS/CZTS/Mo. For both electrolytes, we investigated the precursor composition deviation and the efficiency of the solar cell device; a correlation between composition and conversion efficiency was found. Zn-rich and Cu-poor regions resulted in relatively higher fill factor, open-circuit voltage, and efficiency (η), whereas Sn-rich and Cu-rich regions showed an excess of binary and ternary secondary phases for CZTS layers grown from both electrolytes. The highest efficiency obtained for CZTS_Citrate was 0.64% and CZTS_Pyro was 0.24%. Efficiency losses were attributed to recombination in the bulk film and at the back contact, due to the presence of secondary phases and MoS2, according to time-resolved photoluminescence and photoresponse studies determined by the external quantum efficiency. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication of large-area four-terminal (4 T) perovskite-Si solar cells. Large-area semi-transparent perovskite solar cells were fabricated by utilizing a thin copper layer as the low-cost transparent electrode. Carrier selective contact (CSC)-based Si solar cell was also fabricated with molybdenum oxide (MoOx) hole selective layer. Large-area semi-transparent perovskite solar cells (PSCs) with active areas 1 cm2 and 2 cm2 showed a power conversion efficiency (PCE) of 5.07% and 4.10%, respectively. The CSC Si solar cell displayed a PCE of 3.42%. The CSC-Si cell exhibited an efficiency of 2.24% under filtered light when placed under the semi-transparent perovskite top cell. The four-terminal effect was also demonstrated with a commercially available monocrystalline-Si solar cell. The efficiency of commercial c-Si solar cell was 14.11% under 100 mW cm−2 illumination and 10.08% under filtered light. The combined efficiency values of the 4 T configurations with perovskite top cell and the bottom CSC Si cell, and the commercial c-Si solar cell, were 7.31% and 15.15%, respectively. These values were more than the individual cell efficiencies. [ABSTRACT FROM AUTHOR]

A comprehensive study is reported for temperature-dependent current–voltage (I–V–T), capacitance–voltage (C–V–T), and impedance spectroscopy measurements carried out in the temperature range of 289–413 K for Al/MoOx/n-Si/Al heterojunction solar cell device. Impedance spectroscopy measurements carried out over a broad frequency range (102–106 Hz) exhibit semicircle standard Nyquist's plots implying excellent device stability. An electrical equivalent circuit (EEC) for the device is proposed and the key fitting parameters for the proposed EEC are determined. The C–V–T characteristics of the cell as well as the temperature dependence of the built-in potential, doping gradient, and depletion region width are investigated. Based on the I–V–T measurements, three dominant transport mechanisms are identified in the forward bias regime; thermionic emission (for V < 0.55 V ), trap-space charge limited current due to an exponential distribution of traps (for 0.55 ≤ V < 0.95 V ) and space charge limited current controlled by a single trap state (for 0.95 ≤ V ≤ 2 V ). However, at reverse bias, two different conduction mechanisms, namely Schottky's emission (SE) and Poole–Frenkel's (PF) mechanisms are identified. The temperature dependence of the series and shunt resistances, barrier height, ideality factor as well as the photovoltaic performance of the device under illumination are carefully analyzed. [ABSTRACT FROM AUTHOR]

The effect of annealing the substrate on the structural and optical properties of the nickel oxide thin films containing a fixed ratio of molybdenum was investigated. Energydispersive X-ray spectroscopy (EDX) revealed that the Mo ratio is 4.41 wt%. X-ray diffraction (XRD) revealed that the formed films comprise a phase of NiO0.96. The average crystallite size, dislocation density, and strain function were calculated. Atomic force microscopy (AFM) was employed to investigate the morphology and surface roughness. With the increase in the substrate temperature from 298 K to 673 K, the optical band gap values varied from 3.72 eV to 3.58 eV. [ABSTRACT FROM AUTHOR]

We report the fabrication of binder-free, low-cost and efficient hybrid supercapacitive electrode based on the hexagonal phase of two-dimensional MoS2 nanoworms reinforced with molybdenum nitride nanoflakes deposited on stainless steel (SS) substrate using reactive magnetron sputtering technique. The hybrid nanostructured MoS2–Mo2N/SS thin film working electrode delivers a high gravimetric capacitance (351.62 F g−1 at 0.25 mA cm−2) investigated in 1 M Na2SO4 aqueous solution. The physisorption/intercalation of sodium (Na+) ions in electroactive sites of MoS2–Mo2N composite ensures remarkable electrochemical performance. The deposited porous nanostructure with good electrical conductivity and better adhesion with the current collector demonstrates a high-energy density of 82.53 Wh kg−1 in addition to a high-power density of 24.98 kW kg−1. Further, excellent capacitance retention of 93.62% after 4000 galvanostatic charge–discharge cycles elucidated it as a promising candidate for realizing high-performance supercapacitor applications. [ABSTRACT FROM AUTHOR]