On the grain boundary charge transport in p-type polycrystalline nanoribbon transistors.

Grain boundaries (GB) profoundly influence charge transport, and their localized potential barrier with a high density of defect states plays a crucial role in polycrystalline materials. There are a couple of models to estimate the density of states (DoS) of nanostructured materials in field-effect transistors (FETs) that probe interface traps between the semiconductor and dielectric but not at the grain boundaries. Here, we report on utilizing Levinson's and Seto's models of grain boundary transport and correlate them with the temperature-dependent hopping transport in copper iodide (CuI) polycrystalline nanoribbon (PNR) FETs.

Intermittency of CsPbBr Perovskite Quantum Dots Analyzed by an Unbiased Statistical Analysis.

We analyze intermittency in intensity and fluorescence lifetime of CsPbBr perovskite quantum dots by applying unbiased Bayesian inference analysis methods. We apply change-point analysis (CPA) and a Bayesian state clustering algorithm to determine the timing of switching events and the number of states between which switching occurs in a statistically unbiased manner, which we have benchmarked particularly to apply to highly multistate emitters. We conclude that perovskite quantum dots display a plethora of gray states in which brightness, broadly speaking, correlates inversely with decay rate, confirming the multiple recombination centers model.

Fano Lineshapes and Rabi Splittings: Can They Be Artificially Generated or Obscured by the Numerical Aperture?

Fano resonances and Rabi splittings are routinely reported in the scientific literature. Asymmetric resonance lineshapes are usually associated with Fano resonances, and two split peaks in the spectrum are often attributed to a Rabi splitting. True Fano resonances and Rabi splittings are unequivocal signatures of coherent coupling between subsystems.

Close-Packed Ultrasmooth Self-assembled Monolayer of CsPbBr Perovskite Nanocubes.

The use of colloidal self-assembly to form the complex multiscale patterns in many optoelectronic devices has been a long-standing dream of the nanoscience community. While great progress has been made using charged colloids in polar solvents, controlled assembly from nonpolar solvents is much more challenging. The major challenge is colloidal clustering caused by strong van der Waals (vdW) attraction between long-chain surface capping ligands passivating the surface of nanocrystals.

Monodisperse AuCuSn trimetallic nanocube catalysts.

Monodisperse trimetallic AuCuSn nanocubes are reported where Sn and Cu are inserted into the crystal lattice following co-precipitation protocols along with Au. These trimetallics are explored further towards catalytic hydrazine electrooxidation and their enhanced catalytic activity compared with their bimetallic counterpart AuCu is reported.

Diffusion-Induced Shape Evolution in Multinary Semiconductor Nanostructures.

The classical mechanism of crystal growth for architecting different nanomaterials in solution, although widely studied, is mainly restricted to binary semiconductor systems. However, this method is not applicable to multinary nanomaterials, which have multivalent cations possessing different reactivity under identical reaction conditions. Hence, the shape architectures of these nanostructures, which require a more sophisticated approach, remain relatively unexplored compared to those of binary semiconductors.

Dopant-controlled selenization in Pd nanocrystals: the triggered Kirkendall effect.

Doping foreign impurities in host nanomaterials can induce new materials properties. In addition, doping can also influence the crystallization process and change the shape and/or phase of the host material. While dopant-induced changes in the properties of materials have been well studied, the concept of doping and its chemistry in the design of different nanostructures has rarely been investigated.

Tuning the growth pattern in 2D confinement regime of Sm2O3 and the emerging room temperature unusual superparamagnetism.

Programming the reaction chemistry for superseding the formation of Sm2O3 in a competitive process of formation and dissolution, the crystal growth patterns are varied and two different nanostructures of Sm2O3 in 2D confinement regime are designed. Among these, the regular and self-assembled square platelets nanostructures exhibit paramagnetic behavior analogous to the bulk Sm2O3. But, the other one, 2D flower like shaped nanostructure, formed by irregular crystal growth, shows superparamagnetism at room temperature which is unusual for bulk paramagnet.

Chemical sealing of nanotubes: a case study on Sb2S3.

Implementing the solution chemistry, herein, we report the sealing of both ends of Sb2 S3 semiconductor nanotubes following the diffusion-controlled deposition of the sealing material, AgSbS2 . As a consequence, unique dumbbell-shaped hollow nanocapsules having a binary-ternary epitaxial heterojunction were formed in solution. Whereas these capsule-shaped nanostructures were obtained by the introduction of Ag(0) nanocrystals just after the formation of Sb2 S3 nanotubes, the addition of Ag(0) at the beginning of the process, prior to the formation of nanotubes, changed the growth pattern, and solid nanorods of Sb2 S3 were formed.

Synthesis and photo-darkening/photo-brightening of blue emitting doped semiconductor nanocrystals.

By programming the synthetic reaction chemistry, stable blue emitting Cu(i) or Ag(i) doped Al(iii) co-doped ZnS (Al,Cu:ZnS or Al,Ag:ZnS) semiconductor nanocrystals are designed. Further, the photostability of the obtained intense blue-violet emission is studied, and the effects of doping/co-doping are correlated. Finally, it is revealed that the strong binding surface ligand 1-dodecanethiol and Al(iii) co-doping play pivotal roles in achieving such stable blue emitting doped nanocrystals.

Efficient Superionic Conductor Catalyst for Solid in Solution-Solid-Solid Growth of Heteronanowires.

How efficient could a superionic conductor catalyst be? Beyond the traditionally used molecular precursors when the solution dispersed solid nanomaterials of variable size, shape and phase are introduced under certain reaction condition; the catalyst is found to digest all these structures in minutes irrespective of their phase and morphology, resulting unique heteronanowires. This has been inspected here by employing different ZnSe nanostructures as precursor for Ag2Se nanocrystal catalyst in its superionic conductor phase to obtain the Ag2Se-ZnSe heteronanowires. This dissolution and formation process of these nanostructures is correlated with the change in the reaction temperature profile, the phase of the catalyst, the shape/phase and surface ligands of the source nanostructures, and the possible mechanism of the unique heteronanowires growth has been investigated.

The Redox Chemistry at the Interface for Retrieving and Brightening the Emission of Doped Semiconductor Nanocrystals.

Photo-oxidation of semiconductor quantum dots is the prime concern during their processability, as it often induces nonradiative states and quenches the band edge excitonic emission. Nevertheless, similar effects have been observed for light emitting doped semiconductor nanocrystals, and the dopant emissions are also quenched due to the surface oxidation. This is more pronounced for selenide-based host semiconductors.