US Patent 11950510 Superconductor junction for a solid state cooler

A superconductor junction includes a normal metal layer having a first side and a second side, an insulating layer overlying the second side of the normal metal layer, and a first superconductor layer formed of a first superconductor material that overlies a side of the insulating layer opposite the side that overlies the normal metal layer. The superconductor junction further includes a second superconductor layer formed of a second superconductor material with a first side overlying a side of the first superconductor material opposite the side that overlies the insulating layer. The second superconductor material has a higher diffusion coefficient than the first superconductor material and/or the second superconductor material has a lower recombination coefficient than the first superconductor metal layer. A normal metal layer quasiparticle trap is coupled to a second side of the second superconductor layer.