Porous III-nitrides and methods of using and making thereof

A multilayer structure comprising

• a porous III-nitride layer comprising a plurality of pores therein, wherein the porous III-nitride layer is doped with an n-type dopant and the concentration of the n-type dopant changes across the layer in a doping gradient function over a defined thickness within the layer;
• at least one layer of a bulk non-porous III-nitride,
• wherein the porous III-nitride layer forms an interface with the at least one layer of a bulk non-porous III-nitride;
• wherein the bulk non-porous III-nitride layer is doped with n-type dopant;
• wherein a doping gradient extends across the interface between the porous III-nitride layer and the bulk non-porous III-nitride layer;
• wherein the doping gradient has a concentration of the n-type dopant which changes over a thickness of between about 5 to 100 nm, 5 to 75 nm, 5 to 50 nm, or 5 to 25 nm at the interface with the n-type dopant concentration changing from 5×1018 cm−3 to 1×1020 cm−3 in an optionally linear manner;
• wherein the doping gradient extending across the interface reduces current blocking between the porous III-nitride layer and the bulk non-porous III-nitride layer;
• wherein morphology of the pores of the plurality is a function of the doping gradient;
• and
• wherein the thickness of the doping gradient defines a depletion region within the interface between the porous III-nitride layer and the bulk non-porous III-nitride layer.