Electrical characteristics and physical properties of 8–10 nm silicon dioxide $\left({\text{SiO}}_2\right)$ films formed on Si (100) substrates by use of the nitric acid oxidation of Si method at $\sim 120°\text{C}$ have been investigated. The atomic density of the ${\text{SiO}}_2$ layer increases with the ${\text{HNO}}_3$ concentration. Fourier transformed infrared absorption measurements show that the higher the ${\text{HNO}}_3$ concentration, the higher the atomic density of the ${\text{SiO}}_2$ layer. From the Fowler–Nordheim plots, the barrier height at the ${\text{SiO}}_2/\text{Si}$ interface is found to increase with the ${\text{HNO}}_3$ concentration. The leakage current density flowing through the ${\text{SiO}}_2$ layer decreases with the ${\text{HNO}}_3$ concentration employed for the ${\text{SiO}}_2$ formation. It is concluded that the higher atomic density leads to ${\text{SiO}}_2$ band-gap widening and thus to the higher band discontinuity energy at the ${\text{SiO}}_2/\text{Si}$ interface, which in turn results in a decrease in the tunneling probability of charge carries through ${\text{SiO}}_2$ . The density of oxide fixed charges decreases with an increase in the ${\text{HNO}}_3$ concentration. When postmetallization annealing is performed at $250°\text{C}$ in hydrogen atmosphere on the ${\text{SiO}}_2$ layer formed with $68\text{wt}\mathrm{\%}$ ${\text{HNO}}_3$ , electrical characteristics become as good as those of a thermally grown ${\text{SiO}}_2$ layer formed at $900°\text{C}$ .

We have fabricated thin-film transistors (TFTs) and liquid-crystal displays (LCDs) with monolithic drivers on glass substrates and achieved ultralow power consumption by operating with a low power-supply voltage at 3 V. The gate insulator of the TFTs has a stack structure with an ultrathin interfacial SiO ₂ layer formed by nitric acid oxidation of silicon and a 40-nm-thick SiO ₂ layer formed by plasma-enhanced chemical vapor deposition. Owing to the TFTs with the thin gate insulator, the driving circuits of the LCDs can be operated at a supply voltage of 1.5 V, which is much lower than that of conventional LCDs of 10-15 V.

The scarcity of land resources and food security challenges have prompted more effective uses of the rooftop as well as façade spaces in the urban city of Singapore. Urban rooftop spaces are used for mechanical and electrical (M&E) amenities such as air-conditioning cooling units and water tanks, so the spacious span of the roof area on HDB flats in Singapore is not available. Urban-metabolic farming modules (UmFm) built on 1.5 to 2 m terrace-step terrains have been modelled using BIM Revit to mimic such constraints in rooftop spaces. CFD simulation was conducted for the structure with consideration of the prevailing wind directions at different months of the year. The airflow with the inclusion of mesh netting and varying tiltings of the polycarbonate side façade was simulated to understand their impact on airflow in the growth envelope of the UmFm units under different prevailing wind directions. The amount of solar irradiance received by the crops at different heights in the UmFm due to the sun’s path, and shading of crops grown on the A-frame, was studied using Climate Studio. A comparative verification was done with a scaffold modular unit mounted with temperature, humidity, airflow, and Photosynthesis Photon Flux Density (PPFD) sensors. The digital model of the UmFm unit enables a prior assessment of site feasibility before actual physical implementation on an existing rooftop. It also facilitates plug and play for the UmFm unit to generate an eco-resilient farmscape for an urban city.