This invention is a commercially manufactured article of manufacture (such as a shoulder patch) comprising an infrared (IR) phosphorescent material that emits in the IR wavelength range (e.g., from approximately seven-hundred nanometers (˜700 nm) to approximately one millimeter (˜1 mm)) after being excited by incident wavelengths of between ˜100 nm and ˜750 nm (or visible light). In other words, once the material has been exposed to visible light, the material will continue to emit in the IR wavelength range for a period of time, even when the material is no longer exposed to the visible light.

The present disclosure features a luminescent solar concentrator, including a layer including a quantum-cutting material; and a layer including a broadly light-absorbing material (that is also photoluminescent) optically coupled to and beneath the layer including the quantum-cutting material, relative to a light source.

This invention is a commercially manufactured article of manufacture (such as a shoulder patch) comprising an infrared (IR) phosphorescent material that emits in the IR wavelength range (e.g., from approximately seven-hundred nanometers (700 nm) to approximately one millimeter (1 mm)) after being excited by incident wavelengths of between 100 nm and 750 nm (or visible light). In other words, once the material has been exposed to visible light, the material will continue to emit in the IR wavelength range for a period of time, even when the material is no longer exposed to the visible light.

A method of forming a metal gallate spinel structure that includes mixing a divalent metal-containing salt and a gallium-containing salt in solution with fermentative or thermophilic bacteria. In the process, the bacteria nucleate metal gallate spinel nano-objects from the divalent metal-containing salt and the gallium-containing salt without requiring reduction of a metal in the solution. The metal gallate spinel structures, as well as light-emitting structures in which they are incorporated, are also described.