Overcoming the Charge Confinement-Transport Trade-Off in Perovskite Light-Emitting Diodes

October 9, 2026| Source: Chemical Reviews

Abstract Nanocrystalline metal halide perovskites are promising light emitters for light-emitting diodes (PeLEDs) because they suppress the intrinsic problem of exciton dissociation through charge confinement within nanocrystalline domains. Although these nanostructures have enabled high-emission efficiencies, such confinement strategies typically result in significantly reduced charge transport. This limitation is attributed to numerous grain boundaries, which induce severe charge carrier scattering and trapping, alongside insulating organic ligands typically introduced for defect passivation and size reduction. Poor charge transport increases the required operating voltage and accelerates device degradation pathways under an electrical bias, leading to limited operational lifetimes. This Review examines material design strategies intended to mitigate the competition between charge confinement and transport across various nanocrystalline perovskites. Specifically, we investigate fundamental crystal nucleation and growth mechanisms and evaluate methods to optimize grain size, aiming to minimize the grain boundary to increase charge transport while maintaining charge confinement. Passivation strategies for defect states are also evaluated, emphasizing the engineering of organic ligands to enhance their electrical conductivity while maximizing the passivation efficacy. In addition, the integration of core/shell architectures is discussed as a promising strategy. By controlling the shell composition, these structures promote efficient charge transport while maintaining high radiative recombination rates. Together, these material design strategies aim to overcome the confinement and transport trade-offs in PeLEDs.

Read the original source →

Extensive glacier loss in the coterminous United States.

Glaciers populate the mountain ranges of the western conterminous United States and despite their importance to alpine hydrology, their area and volume change have never been comprehensively evaluated. Our study shows that since the mid-twentieth century about one-quarter of the glaciers have disappeared and the overall area and volume are reduced by one-third. The pattern of glacier shrinkage suggests most glaciers in the conterminous United States are largely maintained by local topographic in

Physical/TechOctober 20, 2026

Ancient DNA challenges to admixture narratives: Insights from Notre-Dame Cemetery (1683-1796) in Colonial Montreal, Canada.

Historical narratives of early colonization in Quebec frequently portray French-Indigenous relations as cooperative and characterized by admixture; which are often mobilized in modern debates on false-indigeneity. These narratives have been studied through genealogical, genetic, and bioarchaeological analyses, yet individuals of African descent remain mostly absent from them, while Indigenous peoples are framed largely in relation to colonists. Notre-Dame Cemetery (1683-1796) in Tiohtià:ke-

Physical/TechOctober 20, 2026

Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis.

Capturing enzymes under native turnover conditions remains a grand challenge in structural biology. Here, we develop a reaction-based cryo-electron microscopy (cryo-EM) strategy that directly samples Drosophila melanogaster cytidine triphosphate synthase (CTPS) from actively catalyzing mixtures containing only natural substrates and allosteric effectors. By integrating reaction-based sampling with three-dimensional variability analysis, we resolve a continuous conformational spectrum of CTPS dur

Physical/TechOctober 20, 2026

GTP orchestrates CTP synthase via an allosteric effector-cycling mechanism.

Cytidine triphosphate (CTP), a fundamental building block of RNA, plays vital roles in diverse biological processes. CTP synthase (CTPS) is the only known enzyme for de novo synthesis of CTP. Efficient CTPS catalysis requires guanosine triphosphate (GTP) in a dose-dependent, nonconsumptive manner; however, the precise mechanism by which GTP drives CTP formation remains unclear. Here, we integrate a series of cryo-EM structures of Drosophila melanogaster CTPS captured from actively catalyzing sam

Physical/TechOctober 20, 2026

Understanding consciousness (biological and artificial) as a society of self-schemas.

This article argues that human cognition is more than the performance of functions such as memory, decision-making, and attention. The brain also builds schematic models of those cognitive functions and uses those models to monitor, predict, and partially control them. When you introspect, your understanding of who you are and what is happening inside of you is derived from those schematic, sometimes inaccurate, but generally useful models, rather than from the actual cognitive functions that ar