Perovskite solar cells containing a mixture of A-site cations show increased activation energies for iodide diffusion.

Impedance spectroscopy shows the bromide concentration required to supress the low frequency response from mobile ions.

No abstract

Hybrid organic-inorganic perovskites have been established as good candidate materials for emerging photovoltaics, with device efficiencies of over 22 % being reported. There are currently only two organic cations, methylammonium and formamidinium, which produce 3D perovskites with band gaps suitable for photovoltaic devices. Numerous computational studies have identified azetidinium as a potential third cation for synthesizing organic-inorganic perovskites, but to date no experimental reports of azetidinium containing perovskites have been published. Here we prepare azetidinium lead iodide for the first time and show that it is a stable, bright orange material that can be successfully used as the absorber layer in solar cells.We also show that it is possible to make mixed cation devices by adding the azetidinium cation to methylammonium lead iodide. Mixed azetidinium-methylammonium cells show improved performance and reduced hysteresis compared to methylammonium lead iodide cells.

The interaction of ionic liquids and conducting polymers were studied, and organic electronic devices fabricated using this new insight.

Lead halide perovskites are mixed electronic-ionic conductors. Ionic mobility is related to device stability; the more favourable ion migration is, the sooner material degradation occurs. The highest efficiency perovskite materials,...

We report the production of nanostructured WO3 photoanodes for solar water splitting produced via anodisation using for the first time citric acid, a safer and more environmentally friendly alternative to fluoride-based electrolytes.

A study using three different pairs of electrochromic polymers (ECPs) synthesized onto plaques by means of a modified vapor phase polymerization (VPP) technique is presented. Restriction of the respective polymerization times, allowed both faster and slower polymerizing monomers to be controlled, and produced blended plaques with visually diffuse interfaces. The ECPs within the blended plaques retain their individual electrochromic behavior and when encapsulated into an electrochromic device, show outstanding optical switching performance with little degradation evident over 10,000 cycles, coupled with a switching time of the order of 1 second. Blends also allow multiple diffuse color changes within an electrochromic device, due to the difference in oxidation potentials of the individual ECPs, making them candidates for adaptive camouflage use.