Ultrafast switching of optical properties in a doped semiconductor by intense femtosecond laser pulses
Peer-Reviewed Publication
Updates every hour. Last Updated: 20-Oct-2026 00:17 ET (20-Oct-2026 04:17 GMT/UTC)
Researchers at Imperial and Exeter investigated why ultrafast optical switching in indium tin oxide reaches saturation – and identified a distinct high-intensity regime not captured by the conventional two-temperature model
To settle inherent irreversible phase transition and motivate re-dissolution of deposited “dead” MnO2 without acid and redox mediator addition, we introduced atomic-dispersed Co atoms with high-spin state into layered MnO2, denoted as Co–MnO2, via an in situ topological phase transformation strategy, thereby unlocking reversible multi-electron transfer chemistry for superb Zn–Mn batteries. Specifically, atomic-distributed Co atoms within Co–MnO2 effectively modulate [MnO6] octahedral symmetry and reduce Co–O bond covalency along with enhanced lattice oxygen activity. Based on this, high-spin Co (t2g4eg2) greatly mitigates the Jahn–Teller distortion as well as promotes electrolytic MnO2 deposited onto the cathode surface completely converted from adsorbed Mn2+ for inhibited “Mn dendrites”, achieving reversible MnO2/Mn3+ and electrolytic MnO2/Mn2+ reactions with highly thermodynamical favorability. Benefiting from the “two-step, three-electron” mechanism triggered by high-spin Co, Zn//Co–MnO2 battery delivers an outstanding capacity of 658 mAh g–1 and ultra-long lifespan over 15,000 cycles. This work reveals the critical role of transition-metal spin state modulation for energy-dense and durable Zn-MnO2 batteries with reversible multi-electron storage mechanisms.
Nitrogen fertilizers are essential for crop production, but much of the nitrogen applied to agricultural soils is lost before plants can use it. These losses not only waste valuable nutrients but also contribute to environmental pollution and greenhouse gas emissions. Scientists have now discovered that adding manganese to biochar can help soil retain more nitrogen by strengthening a natural microbial process.
Agricultural residues, wood waste, and other discarded plant materials could become valuable resources for cleaner energy and environmental technologies. Yet producing consistently high-performing carbon materials from these renewable resources remains a major challenge. Scientists now highlight a critical reason: the properties of the original biomass can determine how well the final carbon material performs.
Nikki Thiele, a staff scientist in the Chemical Sciences Division of the Department of Energy’s Oak Ridge National Laboratory, has received a 2026 NIH Director’s New Innovator Award. The five-year National Institutes of Health grant supports innovative research with the potential for broad impact on biomedical and behavioral science. Thiele will develop innovative chelator designs to improve targeted radiopharmaceuticals.