Phase-engineered high-entropy metastable FCC Cu Ag (In Sn )SeS nanomaterials with high thermoelectric performance.

Crystal-phase engineering to create metastable polymorphs is an effective and powerful way to modulate the physicochemical properties and functions of semiconductor materials, but it has been rarely explored in thermoelectrics due to concerns over thermal stability. Herein, we develop a combined colloidal synthesis and sintering route to prepare nanostructured solids through ligand retention. Nano-scale control over the unconventional cubic-phase is realized in a high-entropy Cu Ag (In Sn )SeS ( = 0-0.

A comparative study of high-pressure behaviors of the two polymorphs of HoGeO.

Two polymorphs of polycrystalline HoGeO, one with tetragonal structure and the other with cubic structure, were synthesized by using different methods. The structural stabilities of these two polymorphs under high pressure were investigated by angle-dispersive X-ray diffraction (ADXRD). Pressure-induced amorphization was found in the tetragonal HoGeO, which is suggested to be associated with the breaking-up of long chains of the edge-shared polyhedron group HoO.

Tuning the Photoresponse of Nano-Heterojunction: Pressure-Induced Inverse Photoconductance in Functionalized WO Nanocuboids.

Inverse photoconductivity (IPC) is a unique photoresponse behavior that exists in few photoconductors in which electrical conductivity decreases with irradiation, and has great potential applications in the development of photonic devices and nonvolatile memories with low power consumption. However, it is still challenging to design and achieve IPC in most materials of interest. In this study, pressure-driven photoconductivity is investigated in n-type WO nanocuboids functionalized with p-type CuO nanoparticles under visible illumination and an interesting pressure-induced IPC accompanying a structural phase transition is found.

Large Band Gap Narrowing and Prolonged Carrier Lifetime of (CHNH)PbI under High Pressure.

Due to their superior optical and electronic properties and good stability, 2D organic-inorganic halide perovskites (OIHPs) exhibit strong potential for optoelectronic applications. However, the large band gap, short carrier lifetime, and high resistance hinder their practical performance. In this work, the band gap is successfully tuned, the carrier lifetime is prolonged, and the resistance of (CHNH)PbI (BAPbI) is reduced directly using high pressure.

A first-principles study on Si as an anode material for rechargeable batteries.

Due to its intriguing geometry, possessing an open-channel structure, Si demonstrates potential for storing and/or transporting Li/Na ions in rechargeable batteries. In this work, first-principles calculations were employed to investigate the phase stability and Li/Na storage and transport properties of the Si anode to evaluate its electrochemical performance for batteries. The intercalation of Li and Na into the Si structure could deliver a capacity of 159 mA h g (LiSi and NaSi), and the average intercalation potentials were 0.

Thermoelectric properties of polycrystalline palladium sulfide.

Measurement of the electrical, thermal, and structural properties of palladium sulfide (PdS) has been conducted in order to investigate its thermoelectric performance. A tetragonal structure with the space group 4/ for PdS was determined from X-ray diffraction measurement. The obtained power factor of 27 μW cm K at 800 K is the largest value obtained for the transition metal sulfides studied so far.