The incorporation of small amounts of phenolic antioxidants, such as 2,6-di-tert-butyl-4-cresol and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], into photovoltaic organo-lead halide perovskite layers significantly suppressed the degradation of the perovskite compounds via light irradiation in the presence of ambient oxygen. While the facile incorporation of the antioxidants did not decrease both the quality of the formed perovskite crystal grains and the photovoltaic conversion performance of the cells, it enhanced the antioxidizing property and water repellency of the perovskite layer owing to the elimination of superoxide anion radical and hydrophobic molecular structure and improved the durability of the cells.

Pendent-type polymers are attractive materials which allow the flexibility to introduce various redox active moieties that facilitate rapid ion/electron transport and enable charge storage. Here, we demonstrate naphthalene diimide polymers with polynorbornene backbone having N-phenyl, PNAn 5 and N-(4-nitrophenyl), PNNO 6. Small changes in the molecular design have led to a significant difference in bulk material and device properties. PNNO 6 maintained 80% of its capacity at 1C after 10 cycles in a Li-ion coin cell. PNAn 5 displayed exceptionally high charge capacity and rate capability with excellent cyclability, maintaining almost its theoretical capacity at various C-rates throughout 500 cycles.

The Packing of submicrometer-sized polystyrene particle within micro-boxes; micrometer-sized squarely recessed pits, was achieved using silicon microfabricated substrates and a simple dipping and pulling-up process. A special phenomenon, cubic packing structures of the particles, was observed when using a micro-box substrate with a few times larger side-length than the particle diameters. Several particle packing structures within different sized micro-boxes were demonstrated, and the relationship between the particle packing structures and micro-box sizes were discussed.