High-performance warm white LED based on thermally stable all inorganic perovskite quantum dots

All inorganic CsPbBr3 quantum dots (QDs) are regarded as excellent candidates for next-generation emitters due to their high photoluminescence quantum yield (PLQY) and defect tolerance. However, the poor stability and degraded luminescent performance may impede their further commercialization because of the separation of conventional ligands from the QDs surfaces. Recently, Zang replaced the regular oleic acid with 2-hexyl-decanoic acid (DA), which possesses higher binding energy on the QDs surfaces, to act as ligands of QDs, exhibiting PLQY of 96% and excellent stabilities against ethanol and water. WLEDs with DA-modified CsPbBr3 QDs achieved improved thermal stability, a color rendering index of 93, a power efficiency of 64.8 lm/W and a properly correlated color temperature value of 3018 K, implying their prominent applications in solid-state lighting and displays

Single atom catalyst having a two dimensional support material.

A method for forming a single atom catalyst on a two-dimensional support material involves providing the two-dimensional support material. The two-dimensional support material is combined with at least two heteroatoms and a metal to form a solution. Liquid is removed from the solution to form a material that includes the two-dimensional support material, the at least two heteroatoms, and the metal. The material including the two-dimensional support material, the at least two heteroatoms, and the metal is heated to form the single atom catalyst that includes single atoms of the metal. The at least two heteroatoms bind the single atoms of the metal to, and stabilize the single atoms of the metal on, the two-dimensional support material

Solar cell with MXene electrode.

A solar cell (100) includes a p-type silicon layer (105) having a first side and a second side and an n-type silicon layer (110) having a first side and a second side. The first side of the n-type silicon layer is arranged on the second side of the p-type silicon layer. The solar cell also includes a first metal electrode (115) arranged on the first side of the p-type silicon layer and a second metal electrode (120) arranged on the second side of the n-type silicon layer. The second metal electrode includes an MXene

Nanogenerator comprising piezoelectric semiconducting nanostructures and Schottky conductive contacts

A semiconducting device includes a substrate, a piezoelectric wire, a structure, a first electrode and a second electrode. The piezoelectric wire has a first end and an opposite second end and is disposed on the substrate. The structure causes the piezoelectric wire to bend in a predetermined manner between the first end and the second end so that the piezoelectric wire enters a first semiconducting state. The first electrode is coupled to the first end and the second electrode is coupled to the second end so that when the piezoelectric wire is in the first semiconducting state, an electrical characteristic will be exhibited between the first electrode and the second electrode

SPEDEN: Reconstructing single particles from their diffraction patterns

Speden is a computer program that reconstructs the electron density of single particles from their x-ray diffraction patterns, using a single-particle adaptation of the Holographic Method in crystallography. (Szoke, A., Szoke, H., and Somoza, J.R., 1997. Acta Cryst. A53, 291-313.) The method, like its parent, is unique that it does not rely on ``back'' transformation from the diffraction pattern into real space and on interpolation within measured data. It is designed to deal successfully with sparse, irregular, incomplete and noisy data. It is also designed to use prior information for ensuring sensible results and for reliable convergence. This article describes the theoretical basis for the reconstruction algorithm, its implementation and quantitative results of tests on synthetic and experimentally obtained data. The program could be used for determining the structure of radiation tolerant samples and, eventually, of large biological molecular structures without the need for crystallization.Comment: 12 pages, 10 figure

Enhanced photoelectrochemical hydrogen production efficiency of MoS2-Si heterojunction.

Photoelectrochemical water splitting is one of the viable approaches to produce clean hydrogen energy from water. Herein, we report MoS 2 /Si-heterojunction (HJ) photocathode for PEC H 2 production. The MoS 2 /Si-HJ photocathode exhibits exceptional PEC H 2 production performance with a maximum photocurrent density of 36.33 mA/cm 2 , open circuit potential of 0.5 V vs. RHE and achieves improved long-term stability up to 10 h of reaction time. The photocurrent density achieved by MoS 2 /Si-HJ photocathode is significantly higher than most of the MoS 2 coupled Si-based photocathodes reported elsewhere, indicating excellent PEC H 2 production performance

Improved characteristics of near-band-edge and deep-level emissions from ZnO nanorod arrays by atomic-layer-deposited Al2O3 and ZnO shell layers

We report on the characteristics of near-band-edge (NBE) emission and deep-level band from ZnO/Al2O3 and ZnO/ZnO core-shell nanorod arrays (NRAs). Vertically aligned ZnO NRAs were synthesized by an aqueous chemical method, and the Al2O3 and ZnO shell layers were prepared by the highly conformal atomic layer deposition technique. Photoluminescence measurements revealed that the deep-level band was suppressed and the NBE emission was significantly enhanced after the deposition of Al2O3 and ZnO shells, which are attributed to the decrease in oxygen interstitials at the surface and the reduction in surface band bending of ZnO core, respectively. The shift of deep-level emissions from the ZnO/ZnO core-shell NRAs was observed for the first time. Owing to the presence of the ZnO shell layer, the yellow band associated with the oxygen interstitials inside the ZnO core would be prevailed over by the green luminescence, which originates from the recombination of the electrons in the conduction band with the holes trapped by the oxygen vacancies in the ZnO shell