Effect of pH dependent morphology on room temperature NH3 sensing performances of beta-Ga2O3
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
Authors: Pilliadugula, Rekha; Krishnan, N. Gopala
Abstract
- beta-Ga2O3 powders were synthesized by hydrothermal method at different pH values ranging from 5 to 14. Obtained powder samples, showed polycrystalline nature and monoclinic crystalline structure upon investigation through XRD. The micrographs of powder samples resulted from SEM investigations showed different morphologies ranging from basic to hierarchical structures as pH value changes. Extremely alkaline solution (with pH = 14) caused to yield hierarchical morphologies whereas the acidic solution (with pH = 5) ensued basic rodlike morphologies. Cocoon shaped morphology was maintained from neutral (pH = 7) to moderately basic (pH = 11) conditions. Optical band gaps of the samples were calculated from Kubelka-Munk plot resulted from the data obtained by UV-Visible spectroscopic analysis. Synthesized beta-Ga2O3 powder samples were drop casted on glass substrate which was pre-printed with Inter Digitated Electrode pattern (IDE) of Silver (Ag) ink. These drop coated thick films are then used for the different concentrations of NH3 vapor detection at room temperature. Morphology based model proposed for room temperature NH3 sensing. It has been observed that beta-Ga2O3 prepared under pH = 14 showed higher response and sensitivity due to its hierarchy in morphology and relatively lower band gap of 4.61 eV.
Constraints on active and sterile neutrinos in an interacting dark energy cosmology
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
Authors: Feng, Lu; He, Dong-Ze; Li, Hai-Li; Zhang, Jing-Fei; Zhang, Xin
Abstract
We investigate the impacts of dark energy on constraining massive (active/sterile) neutrinos in interacting dark energy (IDE) models by using the current observations. We employ two typical IDE models, the interactingwcold dark matter (IwCDM) model and the interacting holographic dark energy (IHDE) model, to make an analysis. To avoid large-scale instability, we use the parameterized post-Friedmann approach to calculate the cosmological perturbations in the IDE models. The cosmological observational data used in this work include the Planck cosmic microwave background (CMB) anisotropies data, the baryon acoustic oscillation data, the type Ia supernovae data, the direct measurement of the Hubble constant, the weak lensing data, the redshift-space distortion data, and the CMB lensing data. We find that the dark energy properties could influence the constraint limits of active neutrino mass and sterile neutrino parameters in the IDE models. We also find that the dark energy properties could influence the constraints on the coupling strength parameter gamma and a positive coupling constant,gamma >0, can be detected at the 2.5 sigma statistical significance for the IHDE+v(s)model by using the all-data combination. In addition, we also discuss the "Hubble tension" issue in these scenarios. We find that theH(0)tension can be effectively relieved by considering massive sterile neutrinos, and in particular in the IHDE+v(s)model theH(0)tension can be reduced to be at the 1.28 sigma level.