Ultraviolet light-emitting device with lateral tunnel junctions for hole injection

摘要

An ultraviolet light-emitting device with a lateral tunnel junction for hole injection includes a PN tunnel junction structure formed on a p-type layer at one side of an active region. The PN tunnel junction structure includes a p-type structure containing a plurality of alternately laminated p-AlGaN barrier layers and p-AlGaN well layers, and an n-type structure containing a plurality of alternately laminated n-AlGaN barrier layers and n-AlInGaN well layers, with the p-type structure facing the p-type layer. Both the p-type structure and the n-type structure have a plurality of projections extending from their surface. The n-type structure is formed on the p-type structure with the projections of the n-type structure fully filling void portions of the p-type structure.

主权项

1. An ultraviolet light-emitting device with a lateral tunnel junction for hole injection comprising:
an n-type layer; a p-type layer; an active region sandwiched between the n-type layer and the p-type layer; and a PN tunnel junction structure formed on the p-type layer, the PN tunnel junction structure comprising: a p-type structure including a plurality of alternately laminated p-AlGaN barrier layers and p-AlGaN well layers, and an n-type structure including a plurality of alternately laminated n-AlGaN barrier layers and n-AlInGaN well layers, with the p-type structure facing the p-type layer; wherein the p-AlGaN barrier layers have a larger Al-composition than that of the p-AlGaN well layers to ensure a valence band offset therebetween not less than 300 meV, the n-AlGaN barrier layers have a larger Al-composition than that of the n-AlInGaN well layers to ensure a conduction band offset therebetween not less than 200 meV; wherein the p-AlGaN barrier layers and the n-AlGaN barrier layers are respectively doped with acceptors and donors of a dopant concentration in the range of 5×1019 cm−3 to 5×1020 cm−3; wherein the p-type structure has a plurality of projections extending from its surface, each of the projections contains numerous alternately laminated p-AlGaN barrier layers and p-AlGaN well layers with edges of the p-AlGaN barrier layers and the p-AlGaN well layers being exposed by sidewalls of the projections; wherein the n-type structure has a plurality of projections extending from its surface, each of the projections contains numerous alternately laminated n-AlGaN barrier layers and n-AlInGaN well layers with edges of the n-AlGaN barrier layers and the n-AlInGaN well layers being exposed by sidewalls of the projections; wherein the n-type structure is formed on the p-type structure with the projections of the n-type structure fully filling void portions of the p-type structure, wherein the void portions of the p-type structure are defined by and surround the projections of the p-type structure.