Topic: optical microscopy

Carrier transport, recombination, ion migration and phase segregation govern optoelectronic devices across nanometre-to-micrometre distances and picosecond-to-hour timescales. Conventional measurements obscure this heterogeneity. Sudipta Seth presents optical microscopy and spectroscopy that convert local material function into spatially and temporally resolved contrast under working conditions. Applied to halide perovskites, these methods expose local fields, transport bottlenecks and defect chemistry affecting solar-cell performance. The resulting mechanisms guide improved probes, interfaces

Colloidal dispersions of rod-like particles are widely accepted as convenient model systems to study the phase behavior of liquid-crystal forming systems, commonly found in LCDs. This is due to the fact that colloidal rods exhibit analogous phase behavior to that of elongated molecules, while they can be directly observed by optical microscopy. Recently, there has been a surge of interest in the liquid crystalline behaviour of so-called bent-core, or banana-shaped, molecules. This is due to their ability to form exotic biaxial nematic phases such as the twist-bend and splay-bend nematic phase,