Abstract
Layered transition metal dichalcogenides have shown tremendous potential for photodetection due to their non-zero direct bandgaps, high light absorption coefficients and carrier mobilities, ...and ability to form atomically sharp and defect-free heterointerfaces. A critical and fundamental bottleneck in the realization of high performance detectors is their trap-dependent photoresponse that trades off responsivity with speed. This work demonstrates a facile method of attenuating this trade-off by nearly 2x through integration of a lateral, in-plane, electrostatically tunable p-n homojunction with a conventional WSe
2
phototransistor. The tunable p-n junction allows modulation of the photocarrier population and width of the conducting channel independently from the phototransistor. Increased illumination current with the lateral p-n junction helps achieve responsivity enhancement upto 2.4x at nearly the same switching speed (14–16 µs) over a wide range of laser power (300 pW–33 nW). The added benefit of reduced dark current enhances specific detectivity (
D*
) by nearly 25x to yield a maximum measured flicker noise-limited
D*
of 1.1×10
12
Jones. High responsivity of 170 A/W at 300 pW laser power along with the ability to detect sub-1 pW laser switching are demonstrated.
Pn heterojunctions comprising layered van der Waals (vdW) semiconductors have been used to demonstrate current-rectifiers, photodetectors, and photovoltaic devices. However, a direct or near-direct ...heterointerface bandgap for enhanced photogeneration in high light-absorbing few-layer vdW materials remains unexplored. In this work, for the first time, density functional theory calculations show that the heterointerface of few-layer group-6 transition metal dichalcogenide (TMD) WSe2 with group-7 ReS2 results in a sizable (0.7 eV) near-direct type-II bandgap. The interlayer IR bandgap is confirmed through IR photodetection, and microphotoluminescence measurements demonstrate type-II alignment. Few-layer flakes exhibit ultrafast response time (5 μs), high responsivity (3 A/W), and large photocurrent-generation and responsivity-enhancement at the hetero-overlap region (10–100×). Large open-circuit voltage of 0.64 V and short-circuit current of 2.6 μA enable high output electrical power. Finally, long-term air-stability and facile single contact metal fabrication process make the multifunctional few-layer WSe2/ReS2 heterostructure diode technologically promising for next-generation optoelectronics.
In recent years there has been a growing interest in the field of Casimir wormhole. In classical general relativity (GR), it is known that the null energy condition (NEC) has to be violated to have a ...wormhole to be stable. The Casimir effect is an experimentally verified effect that is caused due to the vacuum field fluctuations in quantum field theory. Since the Casimir effect provides the negative energy density, thus this act as an ideal candidate for the exotic matter needed for the stability of the wormhole. In this paper, we study the Casimir effect on the wormhole geometry in modified symmetric teleparallel gravity or
f
(
Q
) gravity, where the non-metricity scalar
Q
drives the gravitation interaction. We consider three systems of the Casimir effect such as (i) two parallel plates, (ii) two parallel cylindrical plates, and (iii) two-sphere separated by a large distance to make it more experimentally feasible. Further, we studied the obtained wormhole solutions for each case with energy conditions at the wormhole throat with radius
r
0
and found that some arbitrary quantity violates the classical energy conditions at the wormhole throat. Furthermore, the behavior of the equation of state (EoS) is also analyzed for each case. Finally, we investigate the stability of the obtained Casimir effect wormhole solutions with the generalized Tolman–Oppenheimer–Volkoff (TOV) equation.
India has a longstanding reputation for its acclaimed film industry and continues to be by far the world’s largest producer of films. Nevertheless, domestic demand for films appears to be waning as ...in a number of developed countries with mature film industries. Hence, the econometric analysis in this paper is particularly timely as with demand for films in Indian cinemas falling it is important to identify those factors that make films appealing for Indian audiences. An original dataset is utilised that includes data on all Bollywood films released in India between 2011 and 2015. Account is taken of the potential endogeneity between variables through the use of the generalised method of moments approach. Results are used to demonstrate how the Indian film market can continue to have a significant positive impact on the Indian economy. The discussion highlights appropriate film production company strategies and government policy responses that should be considered to ensure the continued success of the Indian film industry both domestically and in an increasingly competitive international market.
During mustard aphid attack, a huge number of defence proteins’ expression was observed in Indian mustard cultivars cv. Ashirwad and cv. Pusa Mahak. The expression level of those proteins directly ...correlated with the aphid tolerance level of mustard cultivars. The similar expression of defence proteins was observed in a well-known aphid tolerant wild crucifer
Rorippa indica
, where a much higher protein expression level was noted. During the study, one Pentatricopeptide repeat containing protein, F26A19.13 was identified as one of the most important defence protein as it directly blocks the aphid salivary amylase’s function in the plant–insect defence cross-talk.
Abstract
Two-dimensional (2D) topological surface states in a three-dimensional topological insulator (TI) should produce uniform 2D surface current distribution. However, our transport current ...imaging studies on Bi
2
Se
3
thin film reveal non-uniform current sheet flow at 15 K with strong edge current flow. This is consistent with other imaging studies on thin films of Bi
2
Se
3
. In contrast to strong edge current flow in thin films, in single crystal of Bi
2
Se
3
at 15 K our current imaging studies show the presence of 3.6 nm thick uniform 2D sheet current flow. Above 70 K, this uniform 2D sheet current sheet begins to disintegrate into a spatially non-uniform flow. The flow becomes patchy with regions having high and low current density. The area fraction of the patches with high current density rapidly decreases at temperatures above 70 K, with a temperature dependence of the form
$$1/\left| {T - 70} \right|^{0.35}$$
1
/
T
-
70
0.35
. The temperature scale of 70 K coincides with the onset of bulk conductivity in the crystal due to electron doping by selenium vacancy clusters in Bi
2
Se
3
. Thus our results show a temperature dependent competition between surface and bulk conductivity produces a temperature dependent variation in uniformity of current flow in the topological insulator.
We have systematically presented the effect of the generalized uncertainty principle (GUP) in Casimir wormhole space-time in the recently proposed modified gravity, the so-called symmetric ...teleparallel gravity, or
f
(
Q
) gravity. We consider two famous GUP models, such as the Kempf, Mangano, and Mann (KMM) model and the Detournay, Gabriel, and Spindel (DGS) model, in this study. Also, to find the solutions, we assumed two different
f
(
Q
) forms and obtained analytic as well as numerical solutions under the effect of GUP. Besides this, we investigate the solutions with three different redshift functions under an anisotropic fluid located at the throat. Further, we analyzed the obtained wormhole solutions with energy conditions, especially null energy conditions at the wormhole’s throat, and encountered that some arbitrary quantity disrespects the classical energy conditions at the wormhole throat of radius
r
0
. Later, the ADM mass and the volume integral quantifier are also discussed to calculate the amount of exotic matter required near the wormhole throat. Additionally, we show the behavior of the equation of state parameters under the effect of GUP.
The paper examines the empirical relationship between firm‐borrowing channels and aggregate fluctuations for the 100 largest US firms over 2000–2018. The motivation for this study originates from the ...general consensus in macroeconomics that microeconomic shocks to firms cannot generate significant aggregate fluctuations. The analysis extends Gabaix's 2011 baseline model by incorporating measures for “bank shocks” at the firm‐level. In addition to supporting the granular hypothesis, the econometric results indicate that bank shocks have a weak impact on GDP fluctuations, whereas non‐bank loans exert a strong impact on the same. The above findings survive certain robustness checks associated with the presence of oil and monetary shocks, as well as with the firms’ location factor.
Mustard aphids are a serious problem for Brassica oilseed in India causing up to 90% of the crop damage. It was hypothesized that Aphids migrate into the Indo Gangetic plain (IGP) from hilly regions ...of every year. Exact source and migration pattern of this pest is unknown till date. During their long range migration they infested various places over IGP, which fall on their way of migration. The wind, blown from the hilly regions helps aphids to migrate. Meteorological parameters play a crucial role in this migration of aphids. In this study, we have done the 24 hours air-mass backward trajectory at 100 m above ground level (agl) to detect the source regions of mustard aphids. We have found that mainly Western Himalayan hilly regions act as the source of mustard aphids for IGPs. The dependence upon the micro-meteorological parameters and population dynamics are analyzed and discussed elaborately in this work. In this study, we have proposed the 'Hop and Fly' behavior of mustard aphid and further discussed how this migrating behavior could help us to reduce the yield loss of Brassica.
The paper extends Apergis’s (
Energy Policy, 128
, 94–101, 2019) study on the role of fracking activities in housing prices across Oklahoma countries by explicitly considering the role of certain ...indicators determining the health profile of the population. The analysis employs a panel model approach using data from 76 Oklahoma counties, spanning the period 1996–2015. The findings clearly indicate that the overall impact of fracking on housing prices is negative, given that the health indicators are explicitly considered, i.e. fracking has lowered housing prices.
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