Wet etching of delafossite CuGaO 2 and CuCrO 2 thin films was investigated for the first time. CuGaO 2 films were exposed to concentrated HCl, nitric acid, and aluminum etchant at varying temperatures, with etch rates dependent on temperature. Concentrated HCl produced the highest etch rates. CuCrO 2 films were etched using an HCl–HNO 3 mixture at 40 °C–60 °C and chromium-based etchants at dilutions of 1:5 to 1:10. The fastest etching was observed in the 1:5 dilution, and slower rates were achieved through higher dilutions or lower temperatures. Optical microscopy confirmed well-defined patterns, achieving feature sizes as small as 19 μm. Preliminary Arrhenius analysis indicated thermally activated etching behavior, highlighting the strong influence of etchant chemistry on the etching mechanism.

Wet etching of delafossite CuGaO2 and CuCrO2 thin films was investigated for the first time. CuGaO2 films were exposed to concentrated HCl, nitric acid, and aluminum etchant at varying temperatures, with etch rates dependent on temperature. Concentrated HCl produced the highest etch rates. CuCrO2 films were etched using an HCl-HNO3 mixture at 40 degrees C-60 degrees C and chromium-based etchants at dilutions of 1:5 to 1:10. The fastest etching was observed in the 1:5 dilution, and slower rates were achieved through higher dilutions or lower temperatures. Optical microscopy confirmed well-defined patterns, achieving feature sizes as small as 19 mu m. Preliminary Arrhenius analysis indicated thermally activated etching behavior, highlighting the strong influence of etchant chemistry on the etching mechanism.

There has been a growing interest in the field of transparent electronics due to its extensive application across various optical devices such as sensors, solar cells, and displays [1]. Among the various transparent materials, CuGaO 2 has gained significant attention due to its high optical transmission and low electrical resistivity [2]. As advancements in transparent electronics continue, the need for effective and feasible etching methods becomes increasingly critical. Wet etching has emerged as a promising approach due to its advantages over dry etching such as lower operating costs and faster processing. However, despite its potential, the wet etching of CuGaO 2 remains largely unexplored presenting a critical gap in research that must be addressed to facilitate its broader application in device fabrication. In this work, CuGaO 2 thin films were deposited using a dual-target RF magnetron sputtering technique, wherein Cu and Ga 2 O 3 targets were co-sputtered onto quartz and oxidized silicon substrates. The films were deposited at room temperature and subsequently annealed at 900°C. Wet etching was performed using concentrated hydrochloric acid, PAN Etch, and nitric acid. The etch rates at different temperatures were analyzed, and the findings are presented and discussed. [1] A. Stadler, Transparent Conducting Oxides-An Up-To-Date Overview, Materials , 2012, 5 (4), 661–683 [2] A. H. Bharath, A. K. Saikumar and K. B. Sundaram, Deposition and Optical Characterization of Sputter Deposited p-Type Delafossite CuGaO 2 Thin Films Using Cu 2 O and Ga 2 O 3 Targets, Materials , 2024, 17 (7), 1609

CuGaO2 thin films were deposited using the RF magnetron sputtering technique using Cu2O and Ga2O3 targets. The films were deposited at room temperature onto a quartz slide. The sputtering power of Cu2O remained constant at 50 W, while the sputtering power of Ga2O3 was systematically varied from 150 W to 200 W. The films were subsequently subjected to annealing at temperatures of 850 °C and 900 °C in a nitrogen atmosphere for a duration of 5 h. XRD analysis on films deposited with a Ga2O3 sputtering power of 175 W annealed at 900 °C revealed the development of nearly single-phase delafossite CuGaO2 thin films. SEM images of films annealed at 900 °C showed an increasing trend in grain size with a change in sputtering power level. Optical studies performed on the film revealed a transmission of 84.97% and indicated a band gap of approximately 3.27 eV. The film exhibited a refractive index of 2.5 within the wavelength range of 300 to 450 nm.

In this research, the work function (WF) of RF sputtered GZO thin films has been estimated using the electrical characteristics n-Metal Oxide Semiconductor Field Effect Transistor (n-MOSFET) device. Two identical sets of MOSFETs were fabricated in this work using a four-level mask. These MOSFETs have two different types of gate contact materials (Al and GZO respectively). GZO was deposited by using RF magnetron sputtering technique while Al was deposited using the thermal evaporation technique. By comparison of the work function of the two MOSFETs, the work function of RF sputtered GZO thin films was identified to be around 4.58 eV.

For the first time in the literature, the material properties of gallium-doped zinc oxide, grown from a high impulse magnetron sputtering system (HiPIMS), are reported. These material properties are compared to those of a typical radio frequency (RF) sputtering deposition. The films were grown without thermal assistance and were compared across multiple average deposition powers. The films’ resistivity, crystallinity, absorption coefficient, band gap, and refractive index were measured for each of the samples. It was observed that very similar results could be obtained between the HiPIMS and RF sputtering processes under the same average power conditions. It was found that the RF depositions demonstrated a slightly higher band gap and deposition rate as well as lower resistivity and optical absorption coefficient. Band gaps and grain size were found to increase with the power of the deposition for both HiPIMS and RF. These values ranged between 3.45 eV and 3.79 eV and 9 nm and 23 nm in this study, respectively. The absorption coefficient and resistivity were both found to decline with increasing power in both methods but reached minimums of 2800 cm−1 and 0.94 mOhm-cm, respectively, when sputtered using an RF power supply.

The ever-increasing energy consumption has been projected to burden renewable energy sources. It is imperative to look for high-performance clean energy storage systems to sustain future energy demands. Among all the environmentally friendly and efficient energy storage options, supercapacitors are one of the most researched devices. Supercapacitors possess excellent electrochemical properties such as high-power density, superior cyclic stability, fast charging-discharging rates, and high specific capacitance that makes them a fascinating candidate. To improve the energy storage capacity, the two-dimensional counterpart of the supercapacitors is being investigated extensively and manifested unique electrochemical properties. This article thoroughly summarizes the synthesis and characterization techniques adopted for the most recent two-dimensional supercapacitor electrode materials. We focus on the family of carbon-based materials, transition metal oxides and hydroxides, MXenes, and transition metal dichalcogenides that can be employed for clean energy storage applications. The performance of these materials is discussed and compared based on their synthesis technique.

For the first time, this research focuses on the inexpensive technique of synthesis of Cu2In2O5 thin films using intermixing of Cu and In layers, deposited using radio frequency (RF) magnetron sputtering technique. Further, structural, morphological, and optical characterization of Cu2In2O5 thin films have been carried out. The layered films were sputtered using Cu and In targets. The layered structure was subjected to post-deposition annealing at temperatures varying from 700 °C to 1000 °C in a constant oxygen ambiance for five hours. Decomposition of the single-phase Cu2In2O5 takes place at 1000 °C, resulting in the appearance of CuO, In2O3, and Cu2O as decomposition products. Descriptive analysis of the formation of the aforementioned products have been included. However, single-phase Cu2In2O5 thin films were obtained at a post-annealing temperature of 900 °C. The oxidation states of In and Cu have been studied through XPS analysis. Full width half maximum (FWHM), peak positions, satellite peak positions, and their respective binding energies have been elucidated through XPS analysis. An increase in the grain size from 36.8 nm to 115.8 nm with an increase in the annealing temperature from 700 °C to 1000 °C, was noticed from the FESEM images. Optical studies were performed on all the annealed films in the 200–2000 nm wavelength range. The bandgap was in the range of 2.88 to 3.46 eV for the films annealed between 700 °C to 900 °C. The refractive index of the single-phase Cu2In2O5 thin film was obtained to be 1.51.

For the first time, this research focuses on the deposition and characterization of radio frequency (RF) sputtered p-type CuGaO2 thin films using the dual-target sputtering technique with Cu and Ga2O3 targets. The sputtering power to the Cu target was varied from 5 W to 50 W while having the Ga2O3 sputtering power constant at 200 W. The deposited films were subsequently annealed at two different annealing temperatures of 800 °C and 900 °C in N2 ambiance. The effects of variation in Cu sputtering power and annealing temperature on structural, optical, and electrical properties of CuGaO2 thin films are reported in this work. Single-phase CuGaO2 was confirmed in films deposited with Cu sputtering power of 25 W by XRD analysis. XPS analysis revealed a near stoichiometric composition ratio of Cu:Ga in films deposited with Cu sputtering power of 25 W. The optical studies were performed in 200 nm–800 nm wavelengths on all the post-deposition annealed films. The optical transmission was found to decrease with an increase in Cu sputtering power. The optical bandgap was found to be between 3.3 and 4.6 eV. Single-phase CuGaO2 film was p-type with a resistivity of 60 Ω-cm. This resistivity value is one of the lowest ever reported values identified from CuGaO2 thin films.

Inspired by the success of gallium oxide as a wide bandgap semiconductor, aluminum gallium oxide films which possess higher bandgap values have been researched extensively. Higher bandgap values of AGO films have successfully expanded the potential range of applications. In this review, we thoroughly summarize the recent developments in AGO growth, properties, and applications. Deposition techniques and the influence of synthesis parameters on AGO film are examined. Properties of AGO are influenced by the growth techniques and parameters, which promote the AGO films to be employed in desired applications. Electrical properties, optical properties, and morphological studies are discussed in detail. Finally, summary and future perspectives are identified.

In this research, CuGaO2 thin films were prepared on quartz substrates by radio frequency magnetron sputtering technique at 400 °C followed by subsequent annealing in N2 ambiance. The effects of annealing temperature on structural, morphological, optical, and electrical properties of CuGaO2 thin films are reported in this work. X-ray Diffraction (XRD) analysis confirmed the presence of single-phase CuGaO2 in the film annealed at 900 °C. Near stoichiometric composition ratio of Cu:Ga (1:1.08) was identified in the film annealed at 900 °C. The Field Emission Scanning Electron Microscope (FESEM) images showed an increase in the grain size with an increase in annealing temperature. A UV–V is spectrophotometer was used to perform optical studies in the 200–800 nm wavelength region on all films. The optical bandgap was calculated from the transmission studies and was found to be in the range of 2.77 to 3.43 eV. The films annealed at temperatures 800 °C and above were found to be p-type. The lowest resistivity value of 230 Ω-cm was achieved in the film annealed at 900 °C.

Copper indium oxide (Cu2In2O5) thin films were deposited by the RF magnetron sputtering technique using a Cu2O:In2O3 target. The films were deposited on glass and quartz substrates at room temperature. The films were subsequently annealed at temperatures ranging from 100 to 900 °C in an O2 atmosphere. The X-ray diffraction (XRD) analysis performed on the samples identified the presence of Cu2In2O5 phases along with CuInO2 or In2O3 for the films annealed above 500 °C. An increase in grain size was identified with the increase in annealing temperatures from the XRD analysis. The grain sizes were calculated to vary between 10 and 27 nm in films annealed between 500 and 900 °C. A morphological study performed using SEM further confirmed the crystallization and the grain growth with increasing annealing temperatures. All films displayed high optical transmission of more than 70% in the wavelength region of 500–800 nm. Optical studies carried out on the films indicated a small bandgap change in the range of 3.4–3.6 eV during annealing.

Solar energy is becoming more popular and widespread, and consequently, the materials to manufacture solar cells are becoming more limited and costly. Therefore, in order to keep solar energy affordable and available, we must research alternative materials such as copper oxides. Some benefits of copper oxides include being available in abundance, affordable, low toxicity, low bandgap, and a high absorption coefficient—all of which contribute to it being a valuable interest for the manufacturing of solar cells. In this study, CuO thin films were synthesized utilizing RF sputtering technique with deposition occurring at room temperature followed by thermal annealing between 100°C and 400°C and using different gases, oxygen (O2) (oxidizing and reactive gas) and nitrogen (N2) (inert gas), besides air. Afterwards, these thin films were evaluated for a range of wavelengths: 200 - 400 nm (UV spectrum), 400 - 700 nm (Visible spectrum), and 700 - 800 nm (IR spectrum), for both, optical transmittance and photoluminescence. In addition, the CuO results were compared to our Cu2O results from a previous study to assess their differences. In the results of this study, the CuO thin film initially had a bandgap of 2.19 eV at room temperature, and by increasing the annealing temperature to different levels, the bandgap decreased respectively. The presence of air in the chamber allowed for the highest decrease, followed by the nitrogen (N2) and the lowest decrease was observed in the presence of oxygen (O2). This was reflected in the decrease in the bandgap values from 2.19 eV (room temperature) to 2.05 eV for the films annealed at 400°C.

The Cu 2 O thin films were synthesized by using RF sputtering technique.Comparisons were made with films created by deposition at room temperature followed by thermal annealing between 100˚C and 400˚C and using different gases, oxygen (O 2 ) (oxidizing and reactive gas) and nitrogen (N 2 ) (inert gas), besides air.The thickness of the thin films was kept constant, around 2000 Å (Angstrom).In addition, the RF power and pressure deposition were kept constant, as well.The thin films were evaluated for a range of wavelengths between 200 nm and 400 nm (Ultra Violet spectrum), 400 nm and 700 nm (Visible spectrum), 700 nm and 800 nm (Infrared spectrum) for both, optical transmittance and photoluminescence.From the experimental results, the higher annealing temperature and the introduction of nitrogen (N 2 ) gas produced the following results: the optical bandgap for the Cu 2 O was found to be 2.23 eV and photoluminescence peaks were around 551 nm and 555 nm, which matched the theoretical analyses.Overall, there was a decrease in the optical bandgap of the Cu 2 O from 2.56 eV at room temperature to 2.23 eV for the film annealed in nitrogen gas at 400˚C.This indicates that the Cu 2 O is a potential candidate in solar cell applications.

Amorphous hydrogenated boron carbide films were deposited on silicon and glass substrates using radio frequency sputtering. The substrate temperature was varied from room temperature to 300 °C. The substrate temperature during deposition was found to have significant effects on the electrical and optical properties of the deposited films. X-ray photoelectron spectroscopy (XPS) revealed an increase in sp2-bonded carbon in the films with increasing substrate temperature. Reflection electron energy loss spectroscopy (REELS) was performed in order to detect the presence of hydrogen in the films. Metal-insulator-metal (MIM) structure was developed using Al and hydrogenated boron carbide to measure dielectric value and resistivity. Deposited films exhibited lower dielectric values than pure boron carbide films. With higher substrate deposition temperature, a decreasing trend in dielectric value and resistivity of the films was observed. For different substrate temperatures, the dielectric value of films ranged from 6.5–3.5, and optical bandgap values were between 2.25–2.6 eV.

Thin films of CuGa2O4 were deposited using an RF magnetron-sputtering technique for the first time. The sputtered CuGa2O4 thin films were post-deposition annealed at temperatures varying from 100 to 900 °C in a constant O2 ambience for 1.5 h. Structural and morphological studies were performed on the films using X-ray diffraction analysis (XRD) and a Field Emission Scanning Electron Microscope (FESEM). The presence of CuGa2O4 phases along with the CuO phases was confirmed from the XRD analysis. The minimum critical temperature required to promote the crystal growth in the films was identified to be 500 °C using XRD analysis. The FESEM images showed an increase in the grain size with an increase in the annealing temperature. The resistivity values of the films were calculated to range between 6.47 × 103 and 2.5 × 108 Ωcm. Optical studies were performed on all of the films using a UV-Vis spectrophotometer. The optical transmission in the 200–800 nm wavelength region was noted to decrease with an increase in the annealing temperature. The optical bandgap value was recorded to range between 3.59 and 4.5 eV and showed an increasing trend with an increase in the annealing temperature.

Nanoindentation and photoluminescence (PL) studies were performed on hydrogenated boron carbon nitride thin films deposited using radio frequency magnetron sputtering. Dual target sputtering from B4C and BN targets was used to deposit films. The variation in the composition of films was studied using energy-dispersive X-ray spectroscopy. The influence of hydrogen gas and substrate temperature on the mechanical properties was investigated using nanoindentation measurements. Photoluminescence studies were performed on films deposited under varying hydrogen content and different deposition temperatures. The films deposited in this study exhibited hardness of 6–22 GPa and Young’s modulus of 125–140 GPa. PL spectra demonstrated two prominent emission peaks around 499 nm and 602 nm for the deposited films. Increasing the hydrogen gas ratio in the films induced PL peak shifts to longer wavelengths. Emission spectra shifted to long wavelength with increasing substrate temperature. The emission peak position shifted from 499 nm to 544 nm and from 602 nm to 655 nm as a function of substrate temperature. For the first time, BCNH based thin films PL behavior at low temperature (77 K) has been characterized in this study. The BCNH thin films show a rare phenomenon of negative thermal quenching of emission.

Central line-associated blood stream infections (CLABSIs) are the infections caused due to use of central venous catheters in patients. Implanted catheters are susceptible to bacterial colonization, biofilm formation and consequently resulting in infection. CLABSIs continue being important and preventable health-care related infection. Of all the healthcare associated infections, CLABSIs make up to 250,000 cases per year in the US with mortality of up to 35% [1]. Additionally, these infections are associated with high hospital stay durations leading to extremely high cost burden accounting to ~$46,000 per case [2]. However, central venous catheters are imperative in delivery of fluids and medications and to monitor the patient health. Current approach to mitigate this problem heavily focusses on deposition of coatings, inhibiting bacterial adhesion and reducing biofilm formation. In this study, boron carbon nitride (BCN) coatings will be incorporated on central venous catheters for the first time. Boron carbon nitride (BCN) films have achieved attention owing to their crystal structure and unique properties. BCN compounds are expected to combine excellent properties of diamond, boron carbide and boron nitride with their properties adjustable depending on their composition and structure[3]. B-C-N ternary compounds have been reported previously for biological applications [4-7]. Influence of BCN coating on bacterial colonization of gram-positive and gram-negative bacteria will be investigated. BCN films will be deposited using RF sputtering technique. References [1] S. S. Magill et al., "Changes in prevalence of health care–associated infections in US hospitals," New England Journal of Medicine, vol. 379, no. 18, pp. 1732-1744, 2018. [2] Y. Haddadin and H. Regunath, "Central line associated blood stream infections (CLABSI)," in StatPearls [Internet]: StatPearls Publishing, 2019. [3] A. Prakash, S. D. Nehate, and K. B. Sundaram, "Boron carbon nitride based metal-insulator-metal UV detectors for harsh environment applications," Optics letters, vol. 41, no. 18, pp. 4249-4252, 2016. [4] W. Yang, P. Thordarson, J. J. Gooding, S. P. Ringer, and F. Braet, "Carbon nanotubes for biological and biomedical applications," Nanotechnology, vol. 18, no. 41, p. 412001, 2007. [5] A. Bianco, K. Kostarelos, C. D. Partidos, and M. Prato, "Biomedical applications of functionalised carbon nanotubes," Chemical Communications, no. 5, pp. 571-577, 2005. [6] S. H. Mir, V. K. Yadav, and J. K. Singh, "Boron–Carbon–Nitride Sheet as a Novel Surface for Biological Applications: Insights from Density Functional Theory," ACS Omega, vol. 4, no. 2, pp. 3732-3738, 2019. [7] G. Ciofani, S. Danti, G. G. Genchi, B. Mazzolai, and V. Mattoli, "Boron nitride nanotubes: biocompatibility and potential spill‐over in nanomedicine," Small, vol. 9, no. 9‐10, pp. 1672-1685, 2013.

Recent commercialization has peaked interest in transparent conducting oxides being implemented in transparent applications. Gallium doped zinc oxide (GZO) films exhibit excellent transmission characteristics in the visible spectrum while maintaining high electrical conductivity. In majority applications the work function of the material used has an impact on the device performance as it affects the energy barrier height at the hetero-junction interface. Hence, the work function identification is of critical importance. In this article, we discuss work function extraction of GZO from a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) device for the first time. Four level mask sets were used to fabricate two MOSFET devices following exact same conditions. Source and drain contacts were made using aluminum metal for both MOSFETs. One of the MOSFET was fabricated with aluminum as gate contact and the other MOSFET with transparent conducting GZO as its gate contact. GZO used in this research were RF sputtered. From the threshold voltage equation of both the fabricated MOSFETs, work function of GZO was extracted. The electrical and optical transmission studies were also performed on the sputtered GZO thin films and are reported in this study.

BCN materials with varied structures are attracting attention for promising diverse applications. BCN materials are recognized for adaptable electrical properties, outstanding mechanical behavior, exceptional chemical inertness, and high thermal stability, which make them advantageous for corresponding applications in harsh environments. In this article, we thoroughly summarize BCN material theory, growth, properties, and applications. Properties of BCN thin films depend on the composition and growth technique, which facilitates in developing BCN films prevailing between insulating BN and semimetallic graphite. Regarding this, the effects of synthesis parameters on various BCN properties are examined. Dry and wet etching, which are imperative for device processing, are explored. Prompted by the success of graphene, graphene-analogous BCN nanomaterials are being researched intensively due to their unique chemical and physical properties. This article highlights BCN nanomaterials, their synthesis in different dimensions, and properties with prospective applications. We focus on their energy applications in supercapacitors, batteries, oxygen and hydrogen evolution reaction, water purification, and CO2 adsorption along with other biosensing applications. Performance of BCN nanomaterials is discussed and compared with the prevailing benchmark materials to present an evolutionary perspective of BCN nanomaterial progress. Finally, unresolved issues are highlighted, and future development opportunities are identified. (C) 2020 The Author(s). Published by Elsevier Ltd.