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In this paper, we assess the performance of a new label-free deoxyribonucleic acid (DNA) nanosensor based on ballistic carbon nanotube field-effect transistor (CNTFET). The proposed label-free biosensor employs the mechanism of an ultrascaled CNTFET in conjunction with the dielectric and charge modulation concept to electronically detect the neutralized and charged DNA molecules. The proposed DNA nanosensor is endowed with a sensitive channel based on a zigzag carbon nanotube (Z-CNT). The investigation is based on a rigorous quantum simulation, which solves self-consistently the Schrödinger and Poisson equations within the non-equilibrium Green’s function (NEGF) formalism framework. The threshold voltage shift is considered as a biosensing metric. The simulation study includes the potential distribution, Z-CNT charge density, lateral electric-field, $I_{DS}-V_{GS}$ transfer characteristics, subthreshold swing, current spectrum, and sensitivity. Moreover, a parametric analysis is performed to study the impact of ultrascaling issue on the sensitivity behavior. The obtained results empower the proposed nanobiosensor to be considered as a promising candidate for high-performance label-free DNA sensing applications at the nanoscale domain, where the dimensions of bio-measurands are comparable with those of nanobiosensors. [ABSTRACT FROM AUTHOR]

In this paper, the impact of the surface-textured front glass on the absorption of TiO2/glass thin-film ultraviolet (UV) photodetector is investigated, in order to achieve the dual role of increasing the scattering of UV-light as well as reducing the refracting UV-light in the glass. The efficient control of these phenomena may lead to more electric field confinement and UV-light trapping in TiO2 absorber layer. Moreover, semianalytical modeling combined with particle swarm optimization is carried out for studying and enhancing the metal–semiconductor–metal photodetector optical and electrical performances. The results obtained from our semianalytical investigation are validated by comparison with the experimental data. It is found that the absorbance increases significantly by about 51% in optimized design over the planar structure, which is expected to improve the photodetector figures of merit. In this context, photodetector with optimized grooves texturization exhibits a 341% improvement, in terms of responsivity, in comparison with the planar structure and 275% improvement with respect to the textured device without optimization. The obtained results make the proposed design methodology a promising alternative for high-performance optoelectronic applications. [ABSTRACT FROM PUBLISHER]