Perovskite Photovoltaics: For many types of low-cost solar cells, including those using dye-sensitized titania, performance is limited by low open-circuit voltages.
Lee
et al. (p. 643 , published online 4 October; see the Perspective by Norris and Aydil ) have developed a solid-state cell in which structured films of titania or alumina nanoparticles are solution coated with a lead-halide perovskite layer that acts as the absorber and n-type photoactive layer. These particles are coated with a spirobifluorene organic-hole conductor in a solar cell with transparent oxide and metal contacts. For the alumina particles, power conversion efficiencies of up to 10.9% were obtained.
A high-capacity lithium-storage material in metal-oxide form has been synthesized that can replace the carbon-based lithium intercalation materials currently in extensive use as the negative electrode (anode) of lithium-ion rechargeable batteries. This tin-based amorphous composite oxide (TCO) contains Sn(II)-O as the active center for lithium insertion and other glass-forming elements, which make up an oxide network. The TCO anode yields a specific capacity for reversible lithium adsorption more than 50 percent higher than those of the carbon families that persists after charge-discharge cycling when coupled with a lithium cobalt oxide cathode. Lithium-7 nuclear magnetic resonance measurements evidenced the high ionic state of lithium retained in the charged state, in which TCO accepted 8 moles of lithium ions per unit mole.