The development of tin (Sn)‐based perovskite solar cells (PSCs) is hindered by their lower power conversion efficiency and poorer stability compared to the lead‐based ones, which arise from the easy oxidation of Sn2+ to Sn4+. Herein, phenylhydrazine hydrochloride (PHCl) is introduced into FASnI3 (FA = NH2CH  NH2+) perovskite films to reduce the existing Sn4+ and prevent the further degradation of FASnI3, since PHCl has a reductive hydrazino group and a hydrophobic phenyl group. Consequently, the device achieves a record power conversion efficiency of 11.4% for lead‐free PSCs. Besides, the unencapsulated device displays almost no efficiency reduction in a glove box over 110 days and shows efficiency recovery after being exposed to air, due to a proposed self‐repairing trap state passivation process.

In this paper, we prove that a stochastic logistic population under regime switching controlled by a Markov chain is either stochastically permanent or extinctive, and we obtain the sufficient and necessary conditions for stochastic permanence and extinction under some assumptions. In the case of stochastic permanence we estimate the limit of the average in time of the sample path of the solution by two constants related to the stationary probability distribution of the Markov chain and the parameters of the subsystems of the population model. Finally, we illustrate our conclusions through two examples

In this paper, we consider a non-autonomous stochastic Lotka-Volterra competitive system dxi(t) = xi(t)[(bi(t)¡ nPj=1aij (t)xj (t))dt+¾i(t)dBi(t)], where Bi(t) (i = 1; 2; ¢ ¢ ¢ ; n) are independent standard Brownian motions. Some dynamical properties are discussed and the su±cient conditions for the existence of global positive solutions, stochastic permanence, extinction as well as global attractivity are obtained. In addition, the limit of the average in time of the sample paths of solutions is estimated

This paper discusses a randomized non-autonomous logistic equationstandard Brownian motion. In [D.Q. Jiang, N.Z. Shi, A note on non-autonomous logistic equation with random perturbation, J. Math. Anal. Appl. 303 (2005) 164-172], the authors show that E[1/N (t)] has a unique positive T -periodic solution E[1/N p (t)] provided a(t), b(t) and α(t) are continuous T -periodic functions, a(t) > 0, b(t) > 0 and T 0 [a(s) − α 2 (s)] ds > 0. We show that this equation is stochastically permanent and the solution N p (t) is globally attractive provided a(t), b(t) and α(t) are continuous T -periodic functions, a(t) > 0, b(t) > 0 and min t∈[0,T ] a(t) > max t∈[0,T ] α 2 (t). By the way, the similar results of a generalized non-autonomous logistic equation with random perturbation are yielded.

Compared to rechargeable batteries, electrochemical double-layer capacitors (EDLCs) are normally considered to be higher power but lower electrical energy density charge storage devices. To increase the energy density, one can enlarge the interfacial area between electrodes and electrolyte through the introduction of nanopores and employ electrolytes that are stable over wider voltage ranges, such as ionic liquids. However, due to the relatively high viscosity of ionic liquids and large ion sizes, these measures can result in diminished power performance. Here, we describe the synthesis of carbon electrodes that overcome these limitations and simultaneously provide high specific energies and high specific powers in EDLCs using the ionic liquid EMI-TFSI as an electrolyte. A colloidal crystal templating method was optimized to synthesize three-dimensionally ordered mesoporous (3DOm) carbons with well-defined geometry, three-dimensionally interconnected pore structure and tunable pore size in the range from 8 to 40 nm. To achieve precise control over the pore sizes in the carbon products, parameters were established for direct syntheses or seed growth of monodisperse silica nanospheres with specific sizes, using L-lysine-assisted hydrolysis of silicon alkoxide precursors. Porous carbons were then templated from these materials using phenol−formaldehyde (PF) or resorcinol− formaldehyde (RF) precursors. The pore structures of the nanoporous carbon products were characterized in detail, and the materials were tested as electrodes for EDLCs. Optimal pore sizes were identified that provided a large interface between the electrode and the electrolyte while maintaining good ion transport through the relatively viscous electrolyte. 3DOm PF-carbons with pore diameters in the 21−29 nm range exhibited similar high specific capacitance values (146−178 F g −1 at 0.5 A g −1 , with respect to the mass of carbon in a single electrode) as typical large-scale activated-carbon-based EDLCs but showed significantly better high-rate performance (80−123 F g −1 at 25 A g −1 ), a result of the more accessible pore space in which ion diffusion was less restricted.

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Organic light-emitting diodes (OLEDs) based on red and green phosphorescent iridium complexes are successfully commercialized in displays and solid-state lighting. However, blue ones still remain a challenge on account of their relatively dissatisfactory Commission International de L'Eclairage (CIE) coordinates and low efficiency. After analyzing the reported blue iridium complexes in the literature, a new deep-blue-emitting iridium complex with improved photoluminescence quantum yield is designed and synthesized. By rational screening host materials showing high triplet energy level in neat film as well as the OLED architecture to balance electron and hole recombination, highly efficient deep-blue-emission OLEDs with a CIE at (0.15, 0.11) and maximum external quantum efficiency (EQE) up to 22.5% are demonstrated. Based on the transition dipole moment vector measurement with a variable-angle spectroscopic ellipsometry method, the ultrahigh EQE is assigned to a preferred horizontal dipole orientation of the iridium complex in doped film, which is beneficial for light extraction from the OLEDs.

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