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Layered double hydroxide (LDH) is considered a highly promising electrode material for supercapacitors (SCs) due to its high theoretical specific capacitance. However, LDH powders often suffer from poor electrical conductivity, structure pulverization, slow charge transport, and insufficient active sites. Herein, a self‐supporting electrode with a Mott–Schottky heterostructure has been designed for high‐performance SCs. The electrode consists of low crystallinity NiCo‐LDH nanosheets and vertical graphene (VG) directly grown on carbon cloth. The LDH was converted from a metal–organic framework (MOF) by the sol–gel method. This self‐supporting electrode provides fast charge transfer, reducing the pulverization effect and energy barrier. The Mott–Schottky heterostructure of LDH@VG regulates electron density and enhances electron transfer, as confirmed by density functional theory calculation. The optimized LDH@VG heterostructure electrode exhibits an excellent areal capacitance of 5513.8 mF cm−2 and rate capability of 82.1%. Furthermore, the fabricated hybrid SC demonstrates excellent energy density of 404.8 μWh cm−2 at 1.6 mW cm−2 and a remarkable cycling life, with a capacitance of 92.0% after 10 000 cycles. This work not only provides a simple dip‐coating and MOF conversion method to synthesize heterojunction‐based electrodes, but also broadens the horizon for designing advanced electrode materials for SCs. [ABSTRACT FROM AUTHOR]

Portable power supplies, particularly lithium‐ion batteries (LIBs), will play a key role in achieving sustainable development goals, and electrode active materials for the next generation of LIBs with higher energy density and longer life time is highly demanded. For this, in situ visualization of Li behavior during the charge/discharge process is essential, and transmission electron microscopy (TEM) will be promising for this purpose. Here, a quite simple experimental setup consisting of a newly developed Li–C nanocomposite film sputter‐deposited onto Au nanoprotrusions at room temperature and graphene synthesized on a W probe at 500 °C for the in situ TEM observation of the battery reaction is proposed. The preservation of the metallic Li in the Li–C film that is transferred to TEM without using any transfer vessels under atmospheric conditions is confirmed by high resolution TEM before the in situ electrochemical process in TEM. After the one cycle of the in situ electrochemical process, the intercalation of Li ions into graphene (lithiation) is clearly observed. Thus, it is concluded that the metallic Li stored in the Li–C film works well as the anode active material in the electrochemical process for solid state LIBs, implying the developed in situ experimental system is promising. [ABSTRACT FROM AUTHOR]

Urea oxidation reaction (UOR) catalysts are being extensively studied due to the affordability, effortlessness of storage and shipment, non‐toxic and non‐combustible characteristics of urea. Additionally, urine and urea‐containing wastes are being explored as fuels, sources for generating electricity and treating waste water simultaneously in urea fuel cells (UFC). Herein, we report the urea oxidation reaction detected for nitrogen (N) doped carbon nanofibers (CNFs) grown on nichrome (NiCr) foil by chemical vapor deposition (CVD) method and study its various electrochemical parameters to determine its capability as urea fuel cell catalyst. Nickel (Ni) and chromium (Cr) metal particles were observed inside the CNFs structure as an alloy. Ni has been reported to be the most promising catalysts among transition metal catalysts. In this study, we have explored the possibility of a bimetallic transition metal/nitrogen doped carbon supported catalyst to overcome the large overpotentials exhibited by individual Ni‐based catalysts for urea oxidation. The Tafel slope was found to be 640 mV/dec with diffusion coefficient D equal to 4.312×10−13 cm2/s and the anodic transfer coefficient equal to 0.472. The charge transfer impedance was also calculated at 0 V and 0.4 V (onset potential) from the Nyquist plots. Our study revealed that NiCr NCNFs (Nichrome/nitrogen doped carbon nanofibers) exhibited significant UOR in variable molar concentrations of urea in 1 M KOH, making it a suitable candidate for urea oxidation reaction. [ABSTRACT FROM AUTHOR]

In this current study, the behavior of dysprosium oxide (Dy2O3) doped willemite glass‐ceramic (WGC) derived from ZnO‐B2O3‐RHA: Dy2O3 glasses and rice‐husk ash (RHA) works as the active alternative silica has been studied. The fusions of the ternary host system of oxide components doped with rare earth oxide go through the melt‐quench technique followed by solid‐state sintering on the compacted glass frits. The sintered green samples are characterized utilizing the physical, structural, and optical properties to investigate the effect of different sintering temperatures on the samples accordingly. The bulk density of WGC increases together with the increment of sintering temperature from 2.571 to 2.940 g cm–3. Meanwhile, the increment of sintering temperature escalates the crystallization of the main crystalline phase, Zn2SiO4, corroborated by the enlargement of average crystallite size from 161 to 550 nm. Furthermore, the emission activity in the WGC also intensifies on the green emission region (524 nm) accordingly. This fabricated Dy3+:WGC contributes to the nomination as the potential solid‐state lighting material. [ABSTRACT FROM AUTHOR]

2D materials such as molybdenum sulfide (MoS2) integrated with conventional semiconductors lead to the fabrication of novel heterojunctions with pivotal electrical and optoelectronic properties. Herein, an approach is reported which addresses the growth of MoS2 crystals on the lattice‐matched Ga–polar gallium nitride (GaN) wafer using ammonium tetrathiomolybdate (ATM) as a precursor in a chemical vapor deposition (CVD) process, instead of using the molybdenum‐oxide‐based precursors. Unidirectional triangular MoS2 crystals and continuous film are obtained on the free‐standing Ga–polar GaN substrate. Further, the interface quality of the as‐synthesized MoS2 crystals and GaN wafer is explored by X‐ray photoelectron spectroscopy. It is observed that a good quality interface can be obtained by using the ammonia‐containing ATM precursor, where the surface oxygen at the interface is significantly less. A heterojunction device is fabricated with the synthesized MoS2 layer on GaN, showing excellent rectifying diode characteristics and a photovoltaic action with light illumination. This study reveals the suitability of the ammonia‐containing ATM precursor for the growth of MoS2 crystals on GaN in the CVD process to obtain a suitable heterostructure for device applications. [ABSTRACT FROM AUTHOR]

High performance multifunctional electrocatalysts are attracting significant importance for application in energy storage, energy conversion and various other electrochemical reactions. In this prospect, we report on the effective trifunctional electrocatalytic properties of nitrogen (N) doped graphitic carbon nanofibers (CNFs). The CNFs were synthesized on a nichrome (NiCr) foil by chemical vapor deposition (CVD) process. Incorporation of Ni and Cr was observed in the N doped CNFs sample from microscopic and spectroscopic analysis. The metal nanoparticles can be significant in boosting the trifunctional electrocatalytic behavior. The effective oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities were obtained for the CNFs sample with relatively good overpotential values. The electron transfer number per O2 molecule calculated from Koutecky‐Levich (K‐L) plot was found to be 2e− for the ORR reaction. The OER activity of the CNFs is comparable to commercially available iridium oxide (IrO2), signifying the effectiveness of the developed catalyst. Our study revealed that N doped CNFs with incorporation of metal particles synthesized on a binary metal substrate can be significant as ORR, OER, HER trifunctional electrocatalyst. [ABSTRACT FROM AUTHOR]

This study demonstrates graphitization directly through the amorphous carbon under the catalysis of a low‐melting‐point metal, gallium (Ga), by heating in a vacuum heater as well as by Joule heating during in situ transmission electron microscopy (TEM) operation. For the material system of the mixture of Ga nanoparticles (NPs) and amorphous carbon matrix, the graphitization temperature is determined to be about 600 °C for the first time. With increasing the temperature, evaporation and agglomeration of small Ga NPs start to occur together with the graphitization at around the places where Ga NPs would have been located at the surface region. In situ TEM experiment reveals the accelerated increase in electrical conductivity with structural change from amorphous to graphitization. Thus, the combination of the in situ and ex situ TEM observations is believed to be a lead step to understand deeper the graphitization process and provide information in nanoscale. [ABSTRACT FROM AUTHOR]

A development of the technique that enables the simple, rapid, and damage‐free sample preparation for cross‐sectional transmission electron microscopy (X‐TEM) analyses is quite important. Here, we propose a silicon (Si) oxide nanofiber (SON) formed on a tip of an atomic force microscope cantilever as a substrate onto which materials in question are deposited for X‐TEM analyses. Based on the technique for the ion‐irradiation–induced carbon nanofiber (CNF) fabrication onto atomic force microscope cantilever tips, Si‐included CNFs (Si‐CNFs) were fabricated onto cantilever tips. The prepared Si‐CNFs were then annealed at 1000°C in atmospheric ambient to form SON‐tipped cantilevers. Si oxide nanofiber, consisting of mostly Si and O, was linear in shape and was amorphous in crystalline structure. The high performance of the SON‐tipped cantilever was demonstrated for the X‐TEM analyses of ZnO films deposited thereon by an arc plasma deposition method, suggesting that it is promising as a substrate for X‐TEM analyses. [ABSTRACT FROM AUTHOR]

Chemical state analysis is quite important in X‐ray photoelectron spectroscopy. Auger parameter analysis is one of the useful methods to analyze the chemical state in X‐ray photoelectron spectroscopy, because it is not necessary to take the charging effect into account for the analysis of nonconductive materials, especially for the simple material systems of a single chemical state. For the analysis of complicated complex systems, here, we developed the Auger parameter analysis combined with the curve fitting calculation using standard Auger spectra. Copper oxide complexes consisting of a mixture of CuO and Cu2O oxide states were formed on copper platelets by annealing in atmospheric ambient. For those samples, by combining the curve fitting using standard Cu, CuO, and Cu2O Auger spectra, two oxide states were clearly distinguished in the Auger parameter analysis. Thus, this advanced Auger parameter analysis is believed to be promising for the chemical state analysis of complicated complex systems. [ABSTRACT FROM AUTHOR]

Metal‐insulator‐semiconductor (MIS) based Schottky barrier diode (SBD) has significant importance for optoelectronics and other device applications. Here, we demonstrate the fabrication of a highly rectifying Schottky barrier diode (SBD) using a thin hexagonal boron nitride (hBN) interfacial layer in graphene and n‐type gallium nitride (n‐GaN) heterojunction. Significant reduction of reverse saturation current is obtained with the introduction of hBN layer in graphene/n‐GaN interface. The MIS based SBD shows excellent ultraviolet (UV) photoresponsivity with a light/dark ratio of ≈105 at a low reverse bias voltage (−1.5V). Temperature dependent current density‐voltage (J–V) characteristics of the graphene/hBN/n‐GaN heterojunction is investigated to elucidate the current transport behavior. The Schottky barrier height increased with increase in temperature from 0.77 to 0.98 eV in the temperature range of 298–373 K, respectively. The series resistance (RS) is also found to be temperature dependent, where RS decreased with increase in temperature. The understanding of graphene/hBN/n‐GaN heterojunction device characteristics can be significant for photodiode and switching device applications. [ABSTRACT FROM AUTHOR]

We demonstrate the fabrication of a monolayer graphene/β‐Ga2O3 heterostructure and its interesting prospect of producing a suitable Schottky barrier potential for deep‐ultraviolet (DUV) responsive photovoltaic device. The transient response behavior shows a faster response time for photovoltaic mode operation of the photodiode. The fast response at a zero bias is due to generation of photocurrent under an internal built‐in field in the graphene/Ga2O3 interface without any contribution from the trapped carriers. The fabricated device also shows an excellent photoresponsivity of 6.1 A W−1 with a slower response time at a low reverse bias voltage (−1.5 V). The high photoresponsivity at a bias voltage can be related to carrier multiplication due to carriers trapping/release process. Our findings show that the graphene/β‐Ga2O3 heterostructure can be significant for self‐powered/low power consuming DUV detector applications. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis of two new forms of WS2 nanostructures – freestanding WS2 trees and fibers on Au by chemical vapor deposition. It is observed that dislocation‐driven growth causes WS2 crystals to grow and merge in both vertical and horizontal directions to form the pyramidal tree. During the formation of WS2 fibers, the presence of two‐step growth was demonstrated. It is observed that sulphurization of WO3 nanoparticle leads to formation of WS2 rod in the first stage, followed by second stage in which selective growth causes some WS2 layers grow faster compared to other ones leading to the formation of fibrous WS2 structure. Fibers synthesized by our reported method have highly exposed WS2 layers which can demonstrate interesting catalytic and edge related properties or can be functionalized for future applications. [ABSTRACT FROM AUTHOR]

The optimization process of the desired size and quality of graphene domains is usually very difficult due to the numerous interdependent parameters in chemical vapor deposition (CVD). Here, the method so-called 'designs of experiments' is applied to estimate the relative importance and value of some of these parameters and their interactions for the CVD growth of graphene on Cu foil using waste plastic as a solid source. We found that the growth temperature, time, rate of heating, and preannealing time of the substrate influence significantly graphene growth. In particular, the growth time and rate of increasing of the carbon source temperature appear as the main factors for the growth of graphene domains, where the manipulation of only these two parameters could dramatically change the size of crystals. Thus, our experiment shows that for synthesis of larger graphene domains using waste plastic not only do the growth parameters of Cu substrate influence graphene growth but also the carbon source rate of heating. [ABSTRACT FROM AUTHOR]

The CuNi binary alloy can be significant as a catalyst for nitrogen-doped (N-doped) graphene growth considering controllable solubility of both carbon and nitrogen atoms. Here, we report for the first time the possibility of synthesizing substitutional N-doped bilayer graphene on the binary alloy catalyst. Raman spectroscopy, atomic force microscopy and transmission electron microscopy analysis confirm the growth of bilayer and few-layer graphene domains. X-ray photoelectron spectroscopy analysis shows the presence of around 5.8 at% of nitrogen. Our finding shows that large N-doped bilayer graphene domains can be synthesized on the CuNi binary alloy. [ABSTRACT FROM AUTHOR]

We have demonstrated the fabrication of Si- and Ge-incorporated carbon nanofibers (CNFs) at room temperature. Graphite foil surfaces were irradiated by Ar+ and Ne+ ions with simultaneous Si and Ge supply, and the dependences of the ion-induced composite CNFs surface morphology on the ion species and type of incorporated materials were investigated. The sample surfaces were characterized by various kinds of densely distributed nanostructures, such as conical protrusions, nanoneedles, nanocones, and CNF-tipped cones, depending on the Si and Ge supply rates during ion irradiation. In addition, Ne+ irradiation yielded longer CNFs compared to Ar+-irradiated CNFs. Thus, the nanostructures growth was controllable by adjusting the ion and material species. Surface morphology of ion-induced Ge-incorporated CNFs. [ABSTRACT FROM AUTHOR]

Transparent and flexible carbon doped ZnO (C:ZnO) field emission device was successfully fabricated on an arylite substrate. Excellent adhesion of deposited C:ZnO on the flexible substrate was achieved with low sputtering power and Ar flow rate. In the fabricated device, nanostructured C:ZnO and as-deposited thin films were used as field emitter and phosphor screen, respectively. The C:ZnO thin film showed a transparency of about 80% at 550 nm wavelength and average sheet resistance of 1.96 kΩ/□. The C:ZnO phosphor screen emitted red light during the field emission measurement, correlating the dominant cathodoluminescence peak at 646 nm. Thus, a promising transparent and flexible field emission display can be realized with C:ZnO based material. [ABSTRACT FROM AUTHOR]

Stable and high crystalline quality of ZnO nanocones have been successfully fabricated on glass substrates at room temperature. In 3 min irradiation by argon ion on ZnO thin film surface, ZnO nanocones with a number density of 8-15 µm-2 can be observed from SEM images. For a high performance of field emission (FE) device, an emission current stability test was carried out at a fixed electric field of 12 V/µm for 60 min. A stable current of 2.5 µA was observed after 30 min without any obvious irregular current flow. The current density of 1 µA cm-2 was achieved at 9.8 V/µm and 7.8 V/µm before and after stability test, respectively. Even though some of the ZnO nanocones tip were melted due to Joule heating induced by high intensity of electric field, the field enhancement factor are still comparable with other types of nanostructure emitters. The surface morphology of ZnO nanocones after the stability test showed the nanocones of shorter length are not affected by the high electric field at the emission area in which this revealed the robustness of ZnO compared to CNTs/CNFs. The ZnO nanocones at out of the emission area are also not affected by the high electric field or by any heat generated in the vacuum chamber during field emission. Thus, due to the high thermal and mechanical stability, ZnO nanocones is reliable to be as a promising field emitter. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A vacuum ultraviolet (VUV) field emission lamp was developed by using a neodymium ion doped lutetium fluoride (Nd3+ : LuF3) thin film as solid-state phosphor and carbon nanofiber field electron emitters. The thin film was synthesized by pulsed laser deposition and incorporated into the lamp.The cathodoluminescence spectra of the lamp showed multiple emission peaks at 180, 225, and 255 nm. These emission spectra were in good agreement with the spectra reported for the Nd3+ : LuF3 crystal. Moreover, application of an acceleration voltage effectively increased the emission intensity. These results contribute to the performance enhancement of the lamp operating in the VUV region. [ABSTRACT FROM AUTHOR]

Here, we demonstrate the synthesis of graphene on Ag foil by an atmospheric-pressure (AP) chemical vapor deposition (CVD) process as tarnish-resistant coating. Synthesis of a continuous graphene film on Ag foil is achieved using the solid camphor as carbon precursor in a gas mixture of Ar and H2. Tarnishing of the Ag surface through sulfidation is investigated with and without coating of the graphene film. It is observed that the bare Ag surface immediately reacts with sulfur vapor to turn black, whereas graphene coating passivates the Ag surface robustly and thereby restrains the sulfur reaction to preserve from tarnishing. Our findings show that a large-area graphene film can be effectively grown on Ag surface by a CVD process as a tarnish and corrosion resistance barrier. [ABSTRACT FROM AUTHOR]

We demonstrate a unique strategy to fabricate highly transparent and flexible field electron emitters (FEEs) based on combined carbon nanostructures, i.e., conical nanocarbon structures (CNCSs) and single-walled carbon nanotubes (SWNTs). The combined structure was prepared by spray coating of 1,2-dichloroethane (DCE) dispersed SWNTs onto neon ion (Ne+) irradiation induced CNCSs on nafion substrate. The field emission (FE) property of SWCNTs on both flat nafion and CNCSs surfaces increased with increasing the SWCNTs amount. The best FE result was attained for the highest amount of SWCNTs on the CNCSs substrate. This kind of collective structures is found to be effective emitters on transparent and flexible ion-irradiated nafion substrate. Moreover, the combined carbon nanostructures showed improved transparency and emission performance compared to the individual nanostructures. The FE properties of 0.5 ml SWCNTs solution on CNCSs surfaces were equal to those of 1.5 ml SWCNTs solution on flat nafion surface. The hybrid structure based emitters (CNCSs and SWCNTs) produced by this method are lower-cost cathode materials than hybrid structures of SWCNTs and flat nafion. Thus the combined nanostructures of SWCNTs/CNCSs might have huge prospects for the fabrication of efficient transparent and flexible FEEs and their broad application in next-generation portable display devices. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

An efficient cathode material with high transparency (93%) based on conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and single wall carbon nanotubes (SWCNTs) has been developed for the fabrication of highly transparent and flexible field electron emitters (FEE). This kind of material showed superior field emission (FE) performance with very high current density (10-3A/cm2) at very low electric field. The FE performance of the hybrid materials was dramatically improved compared to either SWCNTs and PEDOT:PSS. Thus the hybrid structures of conducting polymer and SWCNTs might be a good choice for use as a cathode material to enhance the FE performance and for potential application in future portable displays. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

We demonstrate the fabrication of a solid state heterojunction photovoltaic device with solution-processed graphene oxide (GO) and n-Si. Partially reduced GO with a high optical gap (2.8 eV) was spin-coated on the n-Si substrate and a heterojunction device was fabricated with the structure of Au/pr-GO/n-Si. In the fabricated device, incident light was transmitted through the thin GO film to reach the junction interface, generating photoexciton, and thereby a photovoltaic action was observed. By means of a built-in electric potential at the GO/n-Si junction, photoexcited electrons and holes can be separated, transported and collected at the electrodes. [ABSTRACT FROM AUTHOR]

We demonstrate synthesis of graphene using the solid precursor camphor in a microwave excited surface wave plasma chemical vapor deposition technique. Highly sublimely camphor was introduced into the plasma chamber in the vapor phase along with Ar and uniform plasma formation was obtained. Rapid deposition of a graphene film on Cu foil was achieved at a relatively low temperature (<600 °C). Raman spectroscopy and transmission electron microscopy clearly showed that the deposited film on Cu foil consist of few-layer graphene. Fully flexible transparent electrode was fabricated by transferring the graphene film with excellent properties for device application. [ABSTRACT FROM AUTHOR]

The present work investigates the relation between ferromagnetism and intrinsic defects of C-doped ZnO thin films. The room-temperature ferromagnetism (RTFM) in C-doped ZnO is due to the charge transfer between Zn 4s and C 2p orbitals. The long-range magnetic interaction in C-doped ZnO is due to carbon-carbon interaction mediated by oxygen. The oxygen- and zinc-related defects in C-doped ZnO affect the mediation of ferromagnetic interaction and the existence of hybridization between Zn and C, respectively. [ABSTRACT FROM AUTHOR]

Highly transparent (transparency 96.5%), flexible and antireflective superhydrophobic (water contact angle >150°) surfaces have been fabricated at room temperature by the ion irradiation method. This one-step fabrication route was fairly easy to carry out without any heat or chemical treatment and can be completed within few seconds. This novel chemical free fabricating strategy could be extended to numerous polymeric substrates to achieve transparent and flexible superhydrophobic structures for their potential applications in diverse fields. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A fully transparent and flexible field emission device (FED) has been demonstrated. Single-walled carbon nanotubes (SWCNTs) coated on arylite substrate were used as electron emitters for the FED and a novel metavanadate phosphor coated on the SWCNTs/arylite film was used as transparent and flexible screen. The SWCNTs/arylite based emitters and the SWCNTs/arylite/metal-vanadate-based phosphor showed a transmittance value of 92.6% and 54%, respectively. The assembled device also showed satisfactory transparency and flexibility as well as producing significant current. Metavanadate phosphor is considered to be an excellent candidate due to its superior luminescence properties and easy fabrication onto transparent and flexible conductive substrate at room temperature while retaining reasonable transparency of the substrate. Thus, its transparency and flexibility will open the door to next-generation FEDs. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Fabrication of heterojunction with transition metal dichalcogenide (TMDC) layers and convention bulk semiconductor is of great interest for optoelectronic device applications. Herein, the influence of interface in a fabricated molybdenum sulfide (MoS2) and p‐type silicon (Si) heterostructure on bias‐dependent photoresponse is demonstrated. The MoS2 layers deposited on the p‐type Si wafer show a photovoltaic action and a photoresponsivity of 139 mA W−1 at 860 nm wavelength for a bias voltage of −5 V. It is observed that the spectral photoresponse of the device enhanced considerably with an applied bias voltage than that of the photovoltaic mode due to an effective field effect across the heterojunction. The increase in photoresponsivity at a higher wavelength (>600 nm) is significant than that of lower wavelength (<500 nm) at the bias voltage. This may due to surface recombination of photocarriers for higher energy photons in the presence of interface states at the MoS2/Si heterojunction. The understanding of photocarriers behavior in the fabricated MoS2/Si heterojunction interface can be critical to develop high photoresponsive heterojunction devices. [ABSTRACT FROM AUTHOR]

Here, the formation of an effective heterojunction with the p‐type γ‐copper iodide (γ‐CuI) and n‐type gallium nitride (GaN) with excellent photodiode characteristics is demonstrated. The γ‐CuI/GaN heterojunction shows good rectification characteristics up to applied bias voltage of ±20 V with low saturation current, thus confirming the suitability of the γ‐CuI film. The heterojunction diode and ultraviolet (UV) photoresponsive characteristics of the device are elucidated with temperature‐dependent transport behavior analysis. With an increase in temperature, reverse saturation current is enhanced, whereas the diode ideality factor is reduced. The heterojunction device shows UV photoresponsive photovoltaic action with a prominent photovoltage of 0.93 V. The temperature‐dependent photovoltaic action is also investigated in the temperature range of 298–373 K, where the open circuit voltage (Voc) decreases with increase in temperature. The photovoltaic action is obtained at a temperature as high as 373 K, indicating that the γ‐CuI/GaN photoresponsive device is quite stable with excellent photovoltage. This study reveals that the effectiveness of γ‐CuI/GaN heterojunction and diode properties to fabricate a heterojunction photodiode with excellent photovoltage and photoresponsivity. [ABSTRACT FROM AUTHOR]

Flow‐induced power generation using nanomaterials, for example, graphene–water interface, has become an attractive energy harvesting mechanism. The effect of heteroatom doping of graphene on flow‐induced electricity is investigated by the authors. Nitrogen‐doped graphene is shown to generate 1.5 times higher power compared with pristine graphene due to surface charges and increase in effective interfacial area. Thus, doping‐induced surface tuning of graphene enhances output performance. The flow‐induced power generation using doped‐graphene allows relaxing the material selection constraints in the triboelectric series. Flow‐induced power generation from graphene‐water interface is investigated. Surface charge and hydrophilicity of graphene is tuned by nitrogen doping. Nitrogen‐doped graphene is shown to generate higher power compared with pristine grapheme. [ABSTRACT FROM AUTHOR]

No abstract is available for this article. [ABSTRACT FROM AUTHOR]