Fabrication and characteristics of back-gate black phosphorus effect field transistors based on PET flexible substrate

Comprehensive Power Gain Assessment of GaN-SOI-FinFET for Improved RF/Wireless Performance Using TCAD

In this work, we present a radio frequency (RF) assessment of the nanoscale gallium nitride-silicon-on-insulator fin field-effect transistor (GaN-SOI-FinFET). All the performances of the device were compared with GaN-FinFET and conventional FinFET (Conv. FinFET) simultaneously. All the results show that the power gains significantly improved in terms of Gma, Gms, Stern stability factor (SS), GMT, and intrinsic delay in comparison with conventional FinFET. Current gain and unilateral power gain were also evaluated for the extraction of fT (cut-off frequency) and f_MAX, respectively. f_T and f_MAX were enhanced by 88.8% and 94.6%, respectively. This analysis was performed at several THz frequencies. Further, the parametric assessment was also performed in terms of gate length and oxide thickness to find the optimized value of gate length and oxide thickness. The implementation of GaN in the channel reduces the parasitic capacitance and paves the way for high-performance RF applications.

Highly stable branched cationic polymer-functionalized black phosphorus electrochemical sensor for fast and direct ultratrace detection of copper ion

Copper ions (Cu²⁺) is an indispensable trace element in the process of metabolism and intake of excessive Cu²⁺ may lead to fatal diseases such as Alzheimer's disease. It is highly demanding to develop a sensitive, selective and convenient method for Cu²⁺ detection. In this work, thin-layer structured polyethyleneimine (PEI) decorated black phosphorus (BP) nanocomposite is one-step synthesized for an electrochemical sensor toward direct detection of Cu²⁺. This sensor achieves a wide detection range of 0.25-177 μM, a low detection limit of 0.02 μM much below the Environmental Protection Agency (EPA) maximum contaminant levels for drinking water (20 μM for Cu²⁺), and much faster response (1.5 s response time) and simpler operation than the conventional tedious anodic stripping voltammetry, ranking one of the best among all reported Cu²⁺ sensor. The great sensing enhancement is mainly due to a synergistic effect of BP and PEI of the composite, of which the former offers the reactivity while the latter splits the thick BP to thin-layer structured PEI-BP composite for larger reaction area. Meanwhile, a flexible sensor has been successfully fabricated and applied in detecting of Cu²⁺ in real samples of river, confirming the application feasibility of PEI-BP sensor in water environment control.