Ni and NiFe alloys with different compositions have been successfully synthesized using a simple, surfactant-free polyol method. The morphological analysis demonstrated a uniform spherical nature of the alloys, with size range ∼10–30 nm. A very thin oxide layer was found to form over the alloy nanoparticles (NPs) which is weakly visible in TEM and later confirmed by XPS analysis. The magnetic properties of the Ni and NiFe NPs were measured using a vibrating sample magnetometer (VSM) at room temperature. The saturation magnetization value was found to be lowest in Ni and keeps on increasing with increasing Fe content in the composition. The resistivity, as revealed from I–V characteristics, was shown to be lowest for the permalloy (Ni₈₀Fe₂₀) phase, while the values increase with further increment in the Fe content. The microwave shielding properties of the Ni and its Fe alloy NPs were investigated in the Ku band range. The lower EM wave transmittance with good reflection and absorption coefficients is responsible for the high shielding values. All of the alloys tested in this investigation showed excellent microwave shielding properties ranging from −21 to −41 dB in the entire Ku band, for ∼1 mm thick samples. The lowest EMI shielding range (−21 to −29 dB) was noted for Ni NPs while the highest was observed in the case of permalloy (−30 to −41 dB). The rest of the NiFe combinations show intermediate shielding effectiveness as compared to Ni and permalloy. Certainly, all of the NiFe alloy combinations we tested showed excellent EMI shielding above −30 dB, with significant enhancements in the absorption shielding efficiency. These alloys are good candidates for EMI shielding having the ability to attenuate 99.9% of electromagnetic radiation.

Development of oxidation resistant conductive inks with low curing temperatures is a challenging problem in printed electronics. The present work introduces a newly formulated room temperature curable conducting ink using multiwalled carbon nanotubes (MWCNTs) for printable electronic application. The organic vehicle composition of the ink is meticulously controlled based on their rheological characteristics. The ink was screen printed on different flexible substrates like paper, Mylar®, photopaper, cellulose acetate sheets and silicone rubber. A morphological study of the printed pattern was also performed using SEM and AFM. The electrical characterization of the ink printed on flexible substrates was studied and a sheet resistance of 0.5–13 Ω sq⁻¹ for three strokes was reported.

Two-dimensional materials play a vital role in the current electronic industry in the fabrication of devices. In the present work, we have exfoliated and stabilized the insulating hexagonal boron nitride (hBN) by means of a polymer-assisted liquid-phase technique. Further, the highly viscous ink of hBN was prepared, and its printability on various commercially available substrates was studied. The morphology of the printed patterns reveals the layered arrangement of hBN. The various electrical and dielectric characterizations, carried out on a metal–insulator–metal capacitor, testified its potential applications in various fields of printed electronics.

Ultraviolet (UV) photodetectors have drawn extensive attention due to their numerous applications in both civilian and military areas including flame detection, UV sterilization, aerospace UV monitoring, missile early warning, and ultraviolet imaging. Zinc oxide (ZnO)-based UV detectors exhibit remarkable performance; however, many of them are not visible-blind, and the fabrication techniques involve a high-temperature annealing step. Here, we fabricated a p–n junction photodiode based on annealing-free ZnO thin films prepared from ZnO nanoparticles and N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB). NPB was chosen due to its transparent nature in the visible region and high hole mobility. The ZnO nanoparticles and thin films were characterized by UV-visible absorption spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scattering (DLS) particle size analysis, Fourier-transform infrared (FTIR) spectroscopy, photoluminescence spectroscopy, XRD and profilometry. The device exhibited responsivity of 0.037 A/W and an external quantum efficiency (EQE) of 12.86% at 5 V bias under 360 nm illumination. In addition, with no biasing, the device exhibited an on–off ratio of more than 10³ and a linear dynamic range (LDR) of 63 dB. A high built-in potential at the ZnO/NPB interface could be the reason for this performance at zero bias. The rise and fall times were 156 ms and 319 ms, respectively. The results suggest that a visible-blind UV photodetector with acceptable performance can be fabricated using annealing-free ZnO films, which may lead to the realization of flexible detectors due to the low-temperature processes involved.