Mg-doped TiO₂ nanorods were synthesized from colloidal titanate by a microwave hydrothermal reaction. Use of such TiO₂ having an elevated conduction band edge as an electron extracting material for ammonium lead halide perovskite solar cells resulted in a marked improvement of V_oc.

A microwave hydrothermal synthesis of size-tunable SnO₂ nanocrystals is achieved by employing a SnCl₄ solution in a mixed ethanol–water solvent. A large increase in ethanol content to over 90%, as well as an increase in SnCl₄ concentration, is the key to successfully obtain highly crystallized and well dispersed SnO₂ particles as large as 26 nm, which can be determined by XRD and HR-TEM observations. Such well ripened SnO₂ crystals exhibit a good performance as photoelectrodes in dye-sensitized solar cells, resulting in an IPCE of around 70% when N719 dye is employed. The size dependent differences in photoelectrochemical properties are studied by SLIM-PCV measurements. The results indicate that fast electron transport occurs with the large SnO₂ crystals, owing to their low electron trap density and shallow distribution.

Solution-processing of thin film encapsulation (TFE) has been a long anticipated technology to bridge the big idea of flexible organic electronics to become real world value, since only small-sized flexible devices are currently achieved with expensive multilayered TFE by complex vacuum processing. Highly demanding conditions are to carry out the process under inert gas, at a low temperature and without aggressive chemicals to avoid damages to the organic materials. Here we show for the first time a solution-processed TFE to totally equal the level of conventional glass-cap encapsulation to achieve a “ready-to-be-used” stability of organic light emitting diode (OLED). A seamless organic/inorganic multilayer in a structure as poly-dimethylsiloxane (PDMS)/SiO_x/SiN_y/SiO_xN_y with built-in compositional gradient, as we named “PONT”, was achieved by combination of two Si-based polymer coatings, UV-curable PDMS, perhydropolysilazane (PHPS) and their photochemical conversion under irradiation of vacuum ultraviolet (VUV) light (λ = 172 nm) in an N₂-filled glovebox at room temperature. PDMS precursors diluted with decamethylcyclopentasiloxane was directly coated to OLED to form a protective layer. The presence of soft, elastic PDMS and its surface conversion to SiO_x to improve wetting resulted in strong adhesion at the interfaces and relaxed strain to avoid cracks in ultra-thin and high density SiO_xN_y to serve as a perfect barrier. Remarkably low water vapor transmission rate < 10^-4 g/m²/day was confirmed for a single PONT as thin as 280 nm. Standardized OLED devices with PONT TFEs have proven 3,864 and 528 h stability under atmospheric (25°C, 50% relative humidity (RH)) and accelerated (60°C, 90%RH) degradation tests, respectively, without formation of non-emissive dark spots in OLEDs. The fast processing of PONT TFE can be applied to roll-to-roll fabrication of various organic devices at low cost and in large areas, since direct solution coating as well as VUV irradiation do not cause any noticeable damages to sensitive organic materials.

The most active and efficient catalysts for the electrochemical hydrogen evolution reaction (HER) rely on platinum, a fact that increases the cost of producing hydrogen and thereby limits the widespread adoption of this fuel. Here, a metal‐free organic electrocatalyst that mimics the platinum surface by implementing a high work function and incorporating hydrogen‐affine hydrogen bonds is introduced. These motifs, inspired from enzymology, are deployed here as selective reaction centres. It is shown that the keto‐amine hydrogen‐bond motif enhances the rate‐determining step in proton reduction to molecular hydrogen. The keto‐amine‐functionalized polymers reported herein evolve hydrogen at an overpotential of 190 mV. They share certain key properties with platinum: a similar work function and excellent electrochemical stability and chemical robustness. These properties allow the demonstration of one week of continuous HER operation without notable degradation nor delamination from the carrier electrode. Scaled continuous‐flow electrolysis is reported and 1 L net molecular hydrogen is produced within less than 9 h using 2.3 mg of polymer electrocatalyst.