Carrier dynamics in monolayer $\mathrm{Mo}{\mathrm{S}}_2$ have been investigated using broadband femtosecond transient absorption spectroscopy (FTAS). A tunable pump pulse was used while a broadband probe pulse revealed ground and excited state carrier dynamics. Interestingly, for pump wavelengths both resonant and nonresonant with the A and B excitons, we observe a broad ground state bleach around 2.9 eV, with decay components similar to A and B. Associating this bleach with the band nesting region between $K$ and Γ in the band structure indicates significant k-space delocalization and overlap among excitonic wave functions identified as A, B, C, and D. Comparison of time dynamics for all features in resonance and nonresonance excitation is consistent with this finding.

Scalable fabrication of two-dimensional materials-based devices with consistent characteristics remains a significant impediment in the field. Here, we report on as-grown monolayer MoS₂ metal-semiconductor-metal photodetectors produced using a CVD process which results in self-contacted two-dimensional material-based devices. The photodetectors show high responsivity (∼1 A/W) even at a low drain-source voltage (V_DS) of 1.5 V and a maximum responsivity of up to 15 A/W when V_DS = 4 V with an applied gate voltage of 8 V. The response time of the devices is found to be on the order of 1 μs, an order of magnitude faster than previous reports. These devices demonstrate the potential of this simple, scalable, and reproducible method for creating as-grown two-dimensional materials-based devices with broad implications for basic research and industrial applications.

Manufacturing of novel transformer oil-based nanofluids has become necessary to improve dielectric and cooling properties. The current study was carried out to examine the dielectric and thermal characteristics of transformer oil incorporated by Mn_0.5 Zn_0.5 Fe₂O₄ nanoparticles (Mn-Zn ferrite NPs) that were synthesized by an auto-combustion technique. The microstructure and morphology of the synthesized Mn-Zn ferrite NPs were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and high-resolution transmission electron microscopy (HRTEM). The formation of a single-phase cubic spinel structure for the Mn-Zn ferrite NPs was confirmed by XRD results. The average crystallite sizes of about 26.7 nm obtained from XRD are very close to the measured value obtained from HRTEM. VSM measurements ensure a high saturation magnetization of 57 emu/g for the Mn-Zn ferrite sample and which makes it a very good candidate as a transformer oil filler. The as-synthesized Mn-Zn ferrite NPs were then introduced into transformer oil with concentrations up to 0.4 g/L to form Mn-Zn nano ferrite-fluid. The dielectric properties of the prepared nano ferrite-fluid samples were investigated by measuring the dielectric constant (ε′) and dissipation factor (tan δ) in the frequency range of 30 Hz − 1 MHz. Moreover, the AC breakdown voltage of the investigated nano ferrite-fluid samples was measured at a constant 500 V/s ramp, and it showed a pronounced enhancement with the addition of Mn-Zn ferrite NPs. It reached 80 % for 0.2 g/L of NPs. Moreover, the convective heat transfer of the nano ferrite-fluid was examined through the heating–cooling process, which is indicating a significant reduction in the thermal time constant in cooling with the introduction of the Mn-Zn ferrite NPs into the oil.

The nanohybrid development of metal oxide/conducting polymer as an energy storage material is an active research area, because of the device stability, conductive behavior, and easy fabrication. Herein, needle-like MnO₂ was coupled with polyaniline fabricated through chemical polymerization followed by the hydrothermal process. The characterization results show that MnO₂/polyaniline exhibited a needle-like morphology. Different characterization techniques such as X-ray diffraction patterns and scanning electron microscopy confirmed the formation of the MnO₂/polyaniline nanohybrids. The electrochemical performance, including cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), specific capacitance (C_sp), and cyclic stability, was examined using a three-electrode assembly cell. The optimized electrode displayed a C_sp of 522.20 F g⁻¹ at a current load of 1.0 A g⁻¹ compared with the other electrodes. The developed synergism during MnO₂/polyaniline fabrication provided enhanced conductive channels and stability during the charge–discharge process.

Borophene's unique anisotropic structure enables highly sensitive polarization photodetection. This review highlights synthesis, device engineering, and AI-driven optimization for advanced polarization imaging and flexible optoelectronics.