Self-trapped emissions in 2D lead-free halide perovskites driven by divalent spacer cations.

The mono- and divalent spacer cation investigation in sodium/indium-based 2D double perovskites revealed significant impacts on optoelectronic properties due to distortions in the inorganic layers. The strong electron-phonon coupling in a novel lead-free Dion-Jacobson phase highlights a promising class for broad-emission devices based on self-trapped excitons (STE), offering enhanced structural stability.

Comparing the Cubic and Tetragonal Phases of MAPbI at Room Temperature.

Stability and maintenance of the crystal structure are the main drawbacks of the application of organic-inorganic perovskites in photovoltaic devices. The Δ = 62 K robust shift of the structural phase transition observed here allows us to conduct a comprehensive study at room temperature of the tetragonal cubic phase on MAPbI. The absence of the shift in the cubic transition for all-inorganic CsPbI samples confirms the importance of both orientation and dynamics of the organic cations.

Synergetic effect of Sn addition and oxygen-deficient atmosphere to fabricate active hematite photoelectrodes for light-induced water splitting.

This work describes the design of a microwave-assisted method using hydrothermal conditions to fabricate pure and Sn-doped hematite photoelectrodes with varied synthesis time and additional thermal treatment under air and N atmosphere. The hematite photoelectrode formed under N atmosphere, with Sn deposited on its surface-which is represented by material synthesized at 4 h -exhibits the highest performance. Hence, Sn addition followed by high temperature annealing conducted in an oxygen-deficient atmosphere seems to create oxygen vacancies, and to prevent the segregation of dopant to form the SnO phase at the hematite crystal surface, reducing its energy and suppressing the grain growth.

Calcium oxalate crystals in eucalypt ectomycorrhizae: morphochemical characterization.

Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells.