P-type beryllium doped gallium nitride semiconductors and methods of production
Exemplary devices such as ultraviolet light emitting diodes (UV LEDs) are disclosed which include conductive Be-doped p-type material with greatly improved efficiency over UV LEDs employing other dopants such as Mg. Exemplary processes for producing Be-doped p-type regions in semiconductor devices are also described.
1 . A light source operable at room temperature, comprising
a first p-type region of Be-doped GaN or AlGaN;
an n-type region that forms a first p-n junction with the first p-type region; and
a second p-type region that forms a second p-n junction with the n-type region, wherein the second p-type region does not include a Be-doped p-type material, wherein the second p-n junction is configured to emit a first UV emission,
wherein the Be-doped GaN or AlGaN of the first p-n junction is configured so that the first UV emission is at least partly absorbed by the Be-doped GaN or AlGaN, wherein UV absorption in the Be-doped GaN or AlGaN causes a transfer of bound holes from a deep state of the Be to a shallow state of the Be, increasing p-type conductivity of the first p-type region,
wherein the first p-n junction is configured to produce a second UV emission after being initiated by the first UV emission.
2 . The light source of claim 1 , wherein the n-type region is Si-doped or Ge-doped GaN or AlGaN.
3 . The light source of claim 1 , wherein the second p-type region is Mg-doped GaN or AlGaN.
4 . The light source of claim 1 , wherein all three of the first p-type region, the n-type region, and the second p-type region physically contact one another.
5 . The light source of claim 1 , wherein the first p-type region and the second p-type region together form a single layer formed on top of the n-type region.