Unraveling Halogen Role in Two-Step Solution Growth of Organic-Inorganic Hybrid Mixed-Halide Perovskites: Guidelines of Fabricating Single-Phase Perovskites with Predictable Stoichiometry.

The challenge faced in optoelectronic applications of halide perovskites is their degradation. Minimizing material imperfections is critical to averting cascade degradation processes. Identifying causes of such imperfections is, however, hindered by mystified growth processes and is particularly urgent for mixed-halide perovskites because of inhomogeneity in growth and phase segregation under stresses.

Nanometer-scaled landscape of polymer: fullerene blends mapped with visible-SNOM.

Bulk heterojunction is one key concept leading to breakthrough in organic photovoltaics. The active layer is expectantly formed of distinct morphologies that carry out their respective roles in photovoltaic performance. The morphology-performance relationship however remains stymied, because unequivocal morphology at the nanoscale is not available.

A concerted three-body formation X+Y+C2H4 in the photodissociation of CH2XCH2Y (X,Y=Br,Cl) at 193 nm.

The photodissociation of CH2XCH2Y (X,Y=Br,Cl) through absorption of 193 nm photons was investigated using product translational spectroscopy. No stable CH2BrCH2 or CH2ClCH2 was detected. The recorded time-of-flight spectra indicate that these internally excited radicals dissociated into Y+C2H4 in a concerted reaction with the first C-X bond rupture.