A new metal−organic framework (MOF), [Zn 4 (μ 4 -O)(μ 6 -L) 2 (H 2 O) 2 ] n • nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N′,N″-bis(4carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn 4 (μ 4 -O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ 6 -L 3− ). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n 2 ) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.

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Specific studies were performed in order to increase the thickness of laser generated directed space charge quasineutral plasma blocks with anomalously high ion current densities above 1011 A/cm2. This may lead to an alternative scheme of laser driven fusion with the irradiation of petawatt-picosecond laser pulses. Initial electron densities were used with Rayleigh profiles, because these are unique for inhomogeneous plasmas for undistorted acceleration at very low reflectivity until thermal absorption processes disturb these ideal conditions. Numerical hydrodynamic results based on a genuine two-fluid code are presented to optimize the block generation for possible fast ignition and details show the delay of thermal exchange between the ion and electron plasma fluid.

This study represents the investigation of earth-abundant and non-toxic CZTSSe absorber materials in kesterite solar cell by using the Finite Element Method (FEM) with (1) electrical, and (2) optical approaches. The simulated results have been validated with the experimental results to define guidelines for boosting the cell performance. For improving the cell efficiency, potential barrier variations in the front contact, and the effect of different lattice defects in the CZTSSe absorber layer have been examined. Controlling the defects and the secondary phases of absorber layer have significant influence on the cell performance improvement. Previous studies have demonstrated that, synthesis of CZTSSe:Na nanocrystals and controlling the S/(S + Se), Cu/(Zn + Sn), and Zn/Sn ratios (stoichiometry) have significant effects on the reduction of trap-assisted recombination (Shockley–Read–Hall recombination model). In this work, a screening-based approach has been employed to study the cell efficiency over a wide range of defect densities. Two categorized defect types including benign defects ($${N}_{t}<{10}^{16}$$ N t < 10 16 cm−3 , Nt defines trap density) and harmful defects $${(N}_{t}>{10}^{16}$$ ( N t > 10 16 cm−3) in the absorber bandgap in the CZTSSe solar cell, by analyzing their position changes with respect to the electron Fermi level (Efn) and the Valence Band Maximum positions have been identified. It is realized that, the harmful defects are the dominant reason for the low efficiency of the kesterite solar cells, therefore, reducing the number of harmful defects and also total defect densities lead to the power conversion efficiency record of 19.06%. This increment makes the CZTSSe solar cells as a promising candidate for industrial and commercial applications.

Measurement of extremely new phenomena during the interaction of laser pulses with terawatt and higher power and picoseconds with plasmas arrived at drastically different anomalies in contrast to the usual observations if the laser pulses were very clean with a contrast ratio higher than 10 8 . This was guaranteed by the suppression of prepulses during less than dozens of ps before the arrival of the main pulse resulting in the suppression of relativistic selffocusing. This anomaly was confirmed in many experimental details, and explained and numerically reproduced as a nonlinear force acceleration of skin layers generating quasi-neutral plasma blocks with ion current densities above 10 11 A/cm 2 . This may support the requirement to produce a fast ignition deuterium tritium fusion at densities not much higher than the solid state by a single shot PW-ps laser pulse. With the aim to achieve separately studied ignition conditions, we are studying numerically how the necessary nonlinear force accelerated plasma blocks may reach the highest possible thickness by using optimized dielectric properties of the irradiated plasma. The use of double Rayleigh initial density profiles results in many wavelength thick low reflectivity directed plasma blocks of modest temperatures. Results of computations with the genuine two-fluid model are presented.

Perovskite solar cells (PSCs) have shown remarkable progress with the rapid increase in power conversion efficiency to reach 25.7% over the last few years. However, it is difficult to precisely determine the energy conversion efficiency for PSC, because of anomalous current density-voltage (J–V) hysteresis. Normal J–V hysteresis has been reported in many papers, where the backward scan performance is higher than the forward scan one. In this work, using Drift–Diffusion Modeling, normal hysteretic behavior associated with ion migration with different scanning rates, pre-bias voltages, and charge-carrier mobility is studied. In addition, the inverted J–V hysteresis by modification of the simulation model, where anions and cations flux towards the transport layers and are accumulated simultaneously on both sides, is achieved. It is also found that the flux parameter values (gae and gch) play a critical role in the reduction of inverted hysteresis and the efficiency enhancement. It is suggested from the current studies that perovskite interfaces encapsulation, which prevents ions migration, could be of great importance for achieving hysteresis-free PSCs and reliable device characteristics.

Here we report on the production of highly directed ion blocks by plasma interaction of ultraviolet wavelength light produced from a KrF laser. This may support the requirement to produce a fast ignition deuterium-tritium fusion at densities not much higher than the solid state by a single shot petawatt-picoseconds ultraviolet laser pulse. Using double Rayleigh initial density profiles, we are studying numerically how the nonlinear force necessary to accelerate plasma blocks may reach the highest possible thickness. Propagation of plasma blocks and the volumetric hot electrons can be shown in detail. Results of computations for wavelengths of two lasers are compared, which show that the block current density for a KrF laser is approximately four times bigger than for the Nd-glass lasers. This is in good agreement with the number predicted by theory.

The interaction of laser pulses of picosecond duration and terawatt to petawatt power accelerated for the very fast undistorted plasma blocks for deuterium DD or deuterium tritium fast ignition is investigated. Based on the direct and instant conversion of laser energy into mechanical motion by nonlinear (ponderomotive) forces, any thermal pressure generation is delayed by the collision process. Following the studying of the classical collision frequency, it is found that the quantum modified collision at higher energies results in a correction by about 15% reduction of the delay.