Thin light-emitting devices and fabrication methods

A semiconducting device comprising:

• a first ZnO-based semiconductor layer of a first conductivity type;
• a second ZnO-based semiconductor layer of a second conductivity type different from the first conductivity type;
• and
• a third semiconductor ZnO-based layer,
• the third semiconductor ZnO-based disposed between the first and second ZnO-based semiconductor layers,
• the dislocation density of the third semiconductor layer is less than about 106 cm−2, and
• each of the first, second and third semiconductor layers is free from a growth substrate.

A light-emitting device comprising:

• a first semiconductor layer of a first conductivity type;
• a second semiconductor layer of a second conductivity type different from the first conductivity type;
• and
• a third semiconductor layer,
• the third semiconductor layer disposed between the first and second semiconductor layers,
• the dislocation density of the third semiconductor layer is less than about 106 cm−2,
• each of the first, second and third semiconductor layers is free from a growth substrate, and
• wherein a peak emission wavelength of the light-emitting device is less than about 500 nm.

A method of fabricating a semiconducting device, comprising:

• depositing, on a ZnO-based substrate, a first layer of material, the first layer of material comprising a ZnO-based material;
• depositing a second layer of material,
• the second layer of material comprising a ZnO-based material with a bandgap different than the bandgap of the first layer of material;
• depositing a third layer of material,
• the third layer of material comprising a ZnO-based material with a bandgap different than the bandgap of the second layer of material;
• the deposition conditions of the first, second and third layers reducing the dislocation density of the second layer below about 106 cm−2;
• and
• removing at least a portion of the ZnO-based substrate.

A semiconducting device comprising:

• a first layer of a first conductivity type;
• a second layer of a second conductivity type different from the first conductivity type;
• and
• a third layer disposed between the first and second layers,
• at least one of the first, second and third layers comprising a ZnO-based semiconductor layer,
• the dislocation density of the third layer is less than about 106 cm−2, and
• each of the first, second and third layers grown on a substrate thinned to a thickness between about 0 and 50 μm.

A semiconducting device comprising:

• a first layer of a first conductivity type;
• a second layer of a second conductivity type different from the first conductivity type;
• a third layer disposed between the first and second layers;
• and
• a thinned substrate,
• at least one of the first, second and third layers comprising a ZnO-based semiconductor layer,
• the dislocation density of the third layer is less than about 106 cm−2, and
• at least one of the first, second and third layers grown on the thinned substrate.