Benzodithiophene-Based Spacers for Layered and Quasi-Layered Lead Halide Perovskite Solar Cells.

Incorporating extended pi-conjugated organic cations in layered lead halide perovskites is a recent trend promising to merge the fields of organic semiconductors and lead halide perovskites. Herein, we integrate benzodithiophene (BDT) into Ruddlesden-Popper (RP) layered and quasi-layered lead iodide thin films (with methylammonium, MA) of the form (BDT) MA Pb I . The importance of tuning the ligand chemical structure is shown as an alkyl chain length of at least six carbon atoms is required to form a photoactive RP (n=1) phase.

Combined reversible switching of ECD and quenching of CPL with chiral fluorescent macrocycles.

Straightforward synthesis and resolution of a series of chiral fluorescent macrocycles are presented, together with their electronic circular dichroism (ECD), strong excimer fluorescence (EF, 300 to 650 nm) and allied highly circularly polarized luminescence (CPL, up to 1.7 × 10). The ECD, EF and CPL responses are strongly affected by the presence of metal ions (Na, Ba) thanks to deep conformational changes.