In this work, the effects of indium tin oxide (ITO) substrates on the structural, compositional, optical dielectric and optical conduction properties of arsenic selenide thin films are investigated. ...The As
2
Se
3
films which are prepared by the thermal deposition technique under vacuum pressure of 10
−5
mbar exhibit an induced crystallization process, improved stoichiometry, increased optical transmittance in the visible range of light and increased dielectric response in the infrared range of light upon replacement of glass substrates by ITO. The ITO/As
2
Se
3
interfaces exhibit conduction and valence band offset values of 0.46 eV and 0.91 eV, respectively. The experimental optical conductivity spectra are theoretically reproduced with the help of the Drude–Lorentz approach for optical conduction. In accordance with this approach, owing to the improved crystallinity of the arsenic selenide, the deposition of As
2
Se
3
onto ITO substrates increases the drift mobility value from ∼ 17.6 cm
2
/Vs to 34.6 cm
2
/Vs. It also reduces the density of free carriers by one order of magnitude. The ITO/As
2
Se
3
/C heterojunction devices which are tested as band filters which may operate in the frequency domain of 0.01–3.0 GHz revealed low pass filter characteristics below 0.35 GHz and band pass filter characteristics in the remaining spectral range.
The phenolic content of methanol and water extracts of ginger fermented by Trichoderma spp. using solid‐state fermentation (SSF) was evaluated and was compared with unfermented ginger. The total ...phenolic content in fermented ginger increased several times. The highest phenolic content in ginger was detected after SSF by T. viride. The optimal physiological conditions for the maximum production of phenolic compounds and β‐glucosidase activity of fermented ginger by T. viride were detected at day 7 incubation, pH 6·0, 30°C and 30% moisture. The SSF of ginger by T. viride greatly enhanced the antioxidant potency of phenolic compounds and was evaluated using DPPH and ABTS assays. A potent antibacterial activity of the phenolic compounds of fermented ginger was observed against all the tested human‐pathogenic bacteria.
Significance and Impact of the Study
This is the first report to investigate the optimal physiological conditions of solid‐state fermentation (SSF) of ginger by Trichoderma viride for enhancing its phenolic content and antioxidant capacity. In addition, the phenolic compounds of fermented ginger could be potentially used as a dietary adjunct and an antibacterial agent.
Significance and Impact of the Study: This is the first report to investigate the optimal physiological conditions of solid‐state fermentation (SSF) of ginger by Trichoderma viride for enhancing its phenolic content and antioxidant capacity. In addition, the phenolic compounds of fermented ginger could be potentially used as a dietary adjunct and an antibacterial agent.
Hybrid organic-inorganic solar cells of the configuration ITO/InSe/TCVA/Au have been fabricated using thermal evaporation technique. The electrical transport mechanisms of the manufactured cell were ...studied by performing the capacitance-voltage (C-V) and the current density-voltage (J-V) estimations. The TCVA/InSe cell displayed rectifying behavior with a rectification ratio of 157 at ±1V. At the lower voltages, the dark current density, J, is ruled by the thermionic emission instrument. While a space charge-limited-conduction mechanism was operated at a higher voltage. The fabricated cell demonstrates a significant improvement in the short circuit photocurrent density and the fill factor by including InSe layer, leading to nearly a nine-fold improvement in the conversion efficiency. The temperature dependent on photovoltaic parameters was also investigated in the temperature range of 303–373K. It found that the power conversion efficiency was increased with the increasing temperature.
•Hybrid organic-inorganic solar cells of ITO/InSe/TCVA/Au have been fabricated.•The fabricated cell exhibited rectifying characteristics.•The cell demonstrates improvement in short circuit photocurrent by including InSe layer.•The power conversion efficiency increased with temperature.
N
,
N
′-Dimethyl-3,4,9,10-perylenedicarboximide (PTCDI-C
1
) thin films were first prepared by thermal evaporation technique. Then, the prepared films were irradiated with gamma rays at room ...temperature with different absorbed doses. The structure of PTCDI-C
1
films at different doses of gamma radiation was elucidated by x-ray diffraction. The results confirmed that PTCDI-C
1
film has a nanostructure morphology. The grain size was observed to decrease slightly with increasing the gamma radiation doses. The temperature dependence of the electrical conductivity was measured in the temperature range of 293–423 K. It was found that the obtained activation energy of PTCDI-C
1
films decreased with increasing gamma radiation dose. The optical parameters were obtained using spectrophotometric measurements. The single oscillator model of Wemple–Didomenico was adopted to study the normal dispersion of refractive index. The optical dispersion parameters of PTCDI-C
1
films such as dispersion energy, oscillator energy and the high frequency dielectric constant were calculated. Furthermore, the nonlinear susceptibility values of PTCDI-C
1
films at different gamma radiation dose were calculated. Also, the dielectric constants of the films were investigated in a large range of frequencies. The fundamental band gap energy values (3.91 eV <
E
g2
< 4.00 eV) of PTCDI-C
1
film were decreased with increasing of gamma radiation doses (150 kGy >
E
g2
> 50 kGy).
In this work, a Ge/BN isotype electronic device that works as a selective microwave bandstop filter is designed and characterized. The interface is designed using a 50‐μm thick p‐type BN on a 0.2‐μm ...thick p‐type germanium thin film. The modeling of current–voltage characteristics of the Al/Ge/BN/C channel of the device revealed that the current is dominated by thermionic emission and by the tunneling of charged particles through energy barriers. The evaluation of the conduction parameters reflected a resonant circuit with a peak‐to‐valley current ratio of (PVCR) of 63 at a peak (Vp) and valley (Vv) voltages of 1.84 and 2.30 V, respectively. The ac signal analysis of the Al/Ge/BN/C channel that was carried out in the frequency range of 1.0–3.0 GHz displayed a bandstop filter properties with notch frequency (fn) of 2.04 GHz and quality factor (Q) of 102. The replacement of the Al electrode by C through the C/Ge/BN/C channel caused the disappearance of the PVCR and shifted fn and Q to 2.70 GHz and 100, respectively. The features of the Ge/BN device are promising as they indicate the applicability of these sensors in communication technology.
Plant growth-promoting bacteria (PGPB) and silicon (Si) can augment salinity tolerance in plants. In this study, 25 potential PGPB were isolated from alfalfa rhizosphere and screened for their ...ability to synthesize indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate deaminase, and solubilize tricalcium phosphate. Two promising strains were tentatively identified as Pseudomonas pseudoalcaligenes (KB-10) and P. putida (KB-25) based on phenotypic, biochemical and 16S rRNA gene phylogeny. Subsequently, a pot experiment was conducted to evaluate the effectiveness of KB-10 and KB-25 treatment, alone or in combination with Si fertilizer, in alleviating salinity stress in coriander. The results showed that treatment with PGPB strains and/or Si significantly increased relative water content, concentrations of photosynthetic pigments, peroxidase activity, total biomass, salt tolerance index, and reduced salt-induced total phenolic contents. Overall data suggested that the combined application of PGPB and Si fertilizer could be a feasible and effective approach to improve growth and salinity tolerance in coriander.
Thin films of 2,9-Bis 2-(4-chlorophenyl)ethyl anthrax 2,1,9-def:6,5,10-d′e′f′ diisoquinoline-1,3,8,10 (2H,9H) tetron (Ch-diisoQ) were prepared by thermal evaporation technique. FTIR-spectra confirmed ...that the thermal evaporation technique is a suitable technique to obtain the appropriate structure of Ch-diisoQ thin films. The complex (real and imaginary parts) permittivity of dielectric demonstrates a noteworthy reliance on the frequency and temperature. The dielectric relaxation behavior is explained in terms of electric modulus formalism. The frequencies identical to the maximum of the imaginary electric modulus at different temperatures were found to comply with an Arrhenius law. The calculated activation energy for this relaxation process is 0.24 eV. The frequency reliance of AC conductivity is found to take after Jonscher’s power law with the relevance of the correlated barrier hopping model.
In this study, the effects of the sandwiching of a 70 nm thick ytterbium film between two layers of CdS on the structural, compositional, optical and electrical properties are investigated. The X-ray ...diffraction, scanning electron microscopy, energy dispersion X-ray, visible light spectroscopy and impedance spectroscopy techniques are employed to achieve these effects. It was observed that, the nanosandwiching of Yb between two 500 nm thick films of CdS enhances the crystalline nature of the films without altering the lattice parameters. Particularly, the grain size is increased by 25%, the strain, the defect density and the stacking faults are reduced by 31.5%, 43.7% and 25%, respectively. Optically, the Yb nanosandwiching is observed to enhance the visible light absorbability by at least 2.7 times of the whole range and by 8 times at 1.64 eV. The enhancement of the absorbability is associated with shrinking in the band gap and more interband states. In addition, an increase in the real part of the dielectric constant by 54% is observed when Yb was nanosandwiched in the CdS structure. The modeling of the imaginary part allowed exploring the electron-plasmon interaction parameters. A remarkable increase in the drift mobility from 281 to 996 cm2/Vs associated with plasmon frequency enhancement from 0.84 to 1.38 GHz was determined upon Yb nanosandwiching. The effectiveness of this modeling was verified from the impedance spectra in the frequency domain of 0.01–1.80 GHz, which revealed wave trapping property of ideal values of return loss at notch frequency of 1.35 GHz. Furthermore, the electrical resistivity measurements on the studied samples have shown that the presence of Yb reduced the electrical resistivity and shifts the donor level closer to the conduction band of CdS. The studies nominate the nanosandwiched CdS for use in optical and microwave technologies as dual devices.
•Yb nanosandwiched CdS thin films are prepared and characterized.•Enhancements in crystallinity and light absorbability are achieved by nanosandwiching.•The Yb Significantly improved the dielectric constant and drift mobility.•Changes in electron-plasmon interactions are investigated.•Impedance spectroscopy confirmed the suitability of the films for dual operations.
In this paper, Erbium(III)-Tris(8-hydroxyquinolinato) (Erq3), with the empirical formula: C27H18ErN3O3, has been introduced as a photoelectronic performance sensor of a promised candidate film with ...high sensitivity to NO2 gas. The present film was prepared by the thermal vacuum process, and the structure and composition of Erq3were investigated by the analysis of XRD-pattern, FTIR-spectra, and AFM technique. A polycrystalline with a single peak (at the centered Bragg’s angle, 2θ = 11.40°) has been observed for the Erq3 film. AFM images indicate that the film surface is composed of distributed plateaus. The absorption spectrum showed three absorption bands at 265 nm corresponding to f-π* transitions, while the peaks at 330 and 375 nm are attributed to the π-π* transitions. The band gap energy was evaluated by Tauc relation, while the electronic transition was indirect. The response time, recovery time, and sensitivity at the operating temperature of 348 K were 1.46 s, 14.2 s, and 20%, respectively. A comparison of sensor parameters with other relative materials was also reported.
Display omitted
•A nano-crystalline with a single peak has been observed for the Erq3 film.•The sensitivity of Erq3 film was 20%.•A comparison of sensor parameters with other relative materials was also reported.
PDF
