Growth of highly conducting MoS2-xNx thin films with enhanced 1T' phase by pulsed laser deposition and exploration of their nanogenerator application.

High-quality growth of MoS2-xNx films is realized on single-crystal c-Al2O3 substrates by the pulsed laser deposition (PLD) in ammonia rendering highly stable and tunable 1T'/2H biphasic constitution. Raman spectroscopy reveals systematic enhancement of 1T' phase component due to the incorporation of covalently bonded N-doping in MoS2 lattice, inducing compressive strain. Interestingly, the film deposited at 300 mTorr NH3 shows ∼80% 1T' phase. The transport measurements performed on MoS2-xNx films deposited at 300 mTorr NH3 display very low room temperature resistivity of 0.03 mΩ-cm which is 100 times enhanced over the undoped MoS2 grown under comparable conditions. A triboelectric nanogenerator (TENG) device containing biphasic MoS2-xNx film as an electron acceptor exhibits a clear enhancement in the output voltage as compared to the pristine MoS2. Device architecture, p-type N doping in MoS2 lattice, favorably increased work-function, multiphasic component of MoS2, and increased surface roughness synergistically contribute to superior TENG performance.

Of Semiotics, the Marginalised and Laws During the Lockdown in India.

On 24th March 2020, the first nationwide complete lockdown was announced by the Prime Minister of India for 21 days which was later extended to 31st May 2020. Consequently, thousands of migrant workers placed in big cities had no other option but to go back to their native villages. Their journeys back to villages- thousands of kilometres on bicycles or foot due to the non-availability of public transport amidst the travel ban- were driven by the compulsions of food and shelter. In one of many heart-wrenching incidents, sixteen laborers were run over by a freight train (all passenger trains in the wake of lockdown had been halted) while they were resting on the railway tracks. The images of the Roti (Indian bread) on the railway track strewn across were beamed on the national news channels, as a telling commentary of the unimaginable hardships of these workers. Ironically, in the eyes of law, they were trespassers under the Indian Railways Act, 1989. The Indian Railway did not pay any compensation to the victims. Their act also violated the Indian Disaster Management Act, 2005 and Indian Penal Code, 1860- the law for the breach of lockdown guidelines and the law for disobedience of order by public servants respectively- for having decided to travel amidst a travel ban. The semiotics of law-making acts 'criminal' bereft of 'moral culpability' are seldom questioned on their supposed amoral foundations. Pandemic exhibited that social fissures not only condition the individual or community actions but also the actions of the State. Minorities especially Muslims were at the receiving end of State's selective enforcement of lockdown laws in India. The various instances in the wake of the COVID-19 pandemic expose the hollow claims of equality before the law and the equal protection of laws as a constitutional promise to every citizen. This article aims to unravel the ostensible and the actual moral exhibition of such Indian laws through the lens of several incidents during the nationwide lockdown in India. This paper would argue that this constructed positivist amorality needs to be deconstructed to unearth the power imbalance that it seeks to hide.

Dynamics of Photo-Generated Carriers across the Interface between CsPbBr3 Nanocrystals and Au-Ag Nanostructured Film, and Its Control via Ultrathin MgO Interface Layer.

The dynamics and control of charge transfer between optoelectronically interesting and size-tunable halide perovskite quantum dots and other juxtaposed functional electronic materials are important issues for the emergent device interest involving such a family of materials in heterostructure configurations. Herein, we have grown bimetallic Au-Ag thin films on glass by pulsed laser deposition at room temperature, which bear nanoparticulate character, and the corresponding optical absorption spectra reveal the expected surface plasmon resonance signature(s). Subsequently, spin-coated CsPbBr3 nanoparticle films onto the bimetallic Au-Ag films exhibit surface-enhanced Raman scattering as well as strong photoluminescence quenching, the latter reflecting highly efficient transfer of photo-generated carriers across the CsPbBr3/Au-Ag interface. Surprisingly, when an ultrathin MgO (insulating) layer of optimum thickness is introduced between the CsPbBr3 and Au-Ag films, the charge transfer is further facilitated with the average lifetime of carriers becoming even shorter. By changing the thickness of the thin MgO layer, the carrier lifetime can in fact be tuned; with the charge transfer getting fully blocked for thick enough MgO layers, as expected. Our study thus throws light on the charge-carrier dynamics in halide perovskites, which is of importance to emergent optoelectronic applications.

Comparative evaluation of MAX, MXene, NanoMAX, and NanoMAX-derived-MXene for microwave absorption and Li ion battery anode applications.

MAX and MXene phases possess unique physical properties, encompassing the realms of both ceramics and metals. Their nanolaminated layered configuration, high anisotropic electrical conductivity, and ability to scatter electromagnetic radiation are beneficial in multiple applications. Herein, detailed applications of MAX and MXene are studied in the fields of microwave absorption and Li ion batteries (LIB). In particular, coatings based on MAX, MXene, ball-milled NanoMAX, and NanoMAX-derived-MXene (MXene-N) and their composites are examined in terms of their comparative efficacy for the aforesaid applications. NanoMAX and MXene-N based composites with graphite exhibit superior performance with specific reflection loss values (representing absorbance when measured with metal-backing) of -21.4 and -19 dB cm3 g-1, respectively, as compared to their bulk counterparts, that too with a low density (0.63 g cm-3) and very small thickness (0.03 mm). These performance improvements in absorbance in only 30 µm coatings can be attributed to reflective losses compounded with multiple internal reflections within the nanocomposite intensified by dielectric losses, arising from high interface density. The pristine samples were also studied for their performance as Li ion battery anodes. Herein, MXene-N exhibits the best performance with a specific capacity of 330 mA h g-1 at 100 mA g-1 and excellent cycling stability tested up to 1000 cycles.

Designing a new family of oxonium-cation based structurally diverse organic-inorganic hybrid iodoantimonate crystals.

Several new structurally diverse carbonyl functional group-based iodoantimonate organic-inorganic hybrid crystals are synthesized using an in situ formed oxonium cationic precursor. These crystals exhibit interesting optoelectronic properties consistent with DFT calculations. Charge transfer and photoluminescence quenching between these crystals and Au nanoparticulate films are examined for potential application interest.