The present application relates to copper-doped double perovskites, for example, copper-doped double perovskites of the formula (I) and to uses thereof, for example as low-bandgap materials such as a semiconducting material in a device. The present application also relates to methods of tuning the bandgap of a Cs.sub.2SbAgZ.sub.6 double perovskite (for example, wherein Z is Cl) comprising doping the double perovskite with copper.
Cs.sub.2Sb.sub.1-aAg.sub.1-bCu.sub.2xZ.sub.6  (I)

An inorganic sulfide solid electrolyte having high air stability, and a preparation method and use thereof In the invention, some or all of P elements in a sulfide electrolyte are replaced with Sb elements, thereby providing an electrolyte having high air stability and ion mobility and applicable to an all-solid lithium secondary battery. The resulting inorganic sulfide electrolyte comprises the following materials: Li.sub.10M(P.sub.1-aSb.sub.a).sub.2S.sub.12, Li.sub.6(P.sub.1-aSb.sub.a)S.sub.5X and Li.sub.3(P.sub.1-aSb.sub.a)S.sub.4, where M is one or more of Ge, Si or Sn, X is one or more of F, Cl, Br or I, and 0.01≤a≤1.

A solid electrolyte material comprises Li, T, X and A wherein T is at least one of Sb, P, As, Si, Ge, Al, and B; X is one or more halogens or N; A is one or more of S or Se. The solid electrolyte material has peaks at 2θ=14.5°±0.50°, 16.8°±0.50°, 23.9°±0.50°, 28.1°±0.50°, and 32.5°±0.50 in X-ray diffraction measurement with Cu-Kα(1,2)=1.54064 Å and may include glass ceramic and/or mixed crystalline phases.

The present application relates to copper-doped double perovskites, for example, copper-doped double perovskites of the formula (I) and to uses thereof, for example as low-bandgap materials such as a semiconducting material in a device. The present application also relates to methods of tuning the bandgap of a Cs.sub.2SbAgZ.sub.6 double perovskite (for example, wherein Z is Cl) comprising doping the double perovskite with copper.

Cs.sub.2Sb.sub.1-aAg.sub.1-bCu.sub.2xZ.sub.6(I)

A solid electrolyte material comprises Li, T, X and A wherein T is at least one of Sb, P, As, Si, Ge, Al, and B; X is one or more halogens or N; A is one or more of S or Se. The solid electrolyte material has peaks at 2?=14.5??0.50?, 16.8??0.50?, 23.9??0.50?, 28.1??0.50?, and 32.5??0.50 in X-ray diffraction measurement with Cu-K?(1,2)=1.54064 ? and may include glass ceramic and/or mixed crystalline phases.