A diode requires the combination of p‐ and n‐type semiconductors or at least the defined formation of such areas within a given compound. This is a prerequisite for any IT application, energy conversion technology, and electronic semiconductor devices. Since the discovery of the pnp‐switchable compound Ag10Te4Br3 in 2009, it is in principle possible to fabricate a diode from a single material without adjusting the semiconduction type by a defined doping level. Often a structural phase transition accompanied by a dynamic change of charge carriers or a charge density wave within certain substructures are responsible for this effect. Unfortunately, the high pnp‐switching temperature between 364 and 580 K hinders the application of this phenomenon in convenient devices. This effect is far removed from a suitable operation temperature at ambient conditions. Ag18Cu3Te11Cl3 is a room temperature pnp‐switching material and the first single‐material position‐independent diode. It shows the highest ever reported Seebeck coefficient drop that takes place within a few Kelvin. Combined with its low thermal conductivity, it offers great application potential within an accessible and applicable temperature window. Ag18Cu3Te11Cl3 and pnp‐switching materials have the potential for applications and processes where diodes, transistors, or any defined charge separation with junction formation are utilized.

Pnp-switchable semiconductor materials are capable of switching their electronic properties from p-to n-type conduction. Observed in the handful of discovered compounds, this behavior is usually accompanied by a temperature-dependent phase transition. During this transition, the dynamical rearrangement of a certain substructure enables the change of the predominant charge carrier type. Considering the immense demand for compact and flexible electronic components, one possible approach is the construction of unconventional one-compound diodes using these pnp-switchable materials. In this study, pnp-switchable AgCuS is applied to realize a functional onecompound diode. AgCuS is accessible in large quantities as bulk material in a simple and short timeframe. Featuring an addressable pnp-switch at 364 K, this material is suitable for diode generation and usage in varied applications. The diode properties of AgCuS devices are reported and illustrate its reversibility and flexibility for diode operation. The material is fully characterized with regards to its electrical and thermal properties, as well as its diode performance. Properties of AgCuS are discussed in relation to the pnp-switchable material Ag 18 Cu 3 Te 11 Cl 3 , which is successfully used to fabricate the first one-compound diode operating close to room temperature.

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Magnesium Ion based Solid State Batteries (MIBs) are subject of intensive studies due to abundance of magnesium, its advantages in volumetric capacity, and the reduced dendrite growth. Here we report on a true solid polymer electrolyte system without liquid additives or plasticizers that reaches conductivities above 10 À 5 S cm À 1 at room temperature and above 10 À 4 S cm À 1 at 50 °C. An electrospun polymer electrolyte membrane fabricated from a polymer electrolyte featuring a composition of PEO : Mg(TFSI) 2 36 : 1 [where PEO stands for poly(ethyleneoxide) and Mg(TFSI) 2 for magnesium bis(trifluoromethanesulfonyl) imide] was identified as the best performing system. Magnesium transport was substantiated by different methods, and the electrochemical properties including solid electrolyte interface (SEI) formation were investigated. Electrospinning as a preparation method has been identified as a powerful tool to enhance the electrochemical properties beyond conventional polymer membrane fabrication techniques.

Coinage metal chalcogenides offer ideal prerequisites for high thermoelectric performance and sensor applications, with their usually low lattice thermal and high electrical conductivity, as well as small band gaps. In the solid solution Cu1.5Se y Te1–y we synthesized phase pure materials with y = 0.2–0.7 and characterized them concerning selected physical properties. X-ray crystal structure determination was performed for two representatives of the solid solution, Cu1.5Se0.3Te0.7 and Cu1.5Se0.5Te0.5. The entire series crystallizes cubically, in space group Pm3̅n. No structural changes are observed between room temperature and the synthesis temperature of 723 K. The conductivity measurements and Seebeck coefficients of Cu1.5Se0.3Te0.7 and Cu1.5Se0.5Te0.5 indicate that the two representatives are narrow band gap semiconductors (E g 0.06–0.08 eV). Both compounds show positive Seebeck coefficients and reasonably low thermal conductivities at moderate temperatures. Cu1.5Se0.5Te0.5 is characterized by a bulk modulus of 40.9 GPa.