Method of manufacturing an ultraviolet light emitting AlGaN composition and ultraviolet light emitting device containing same

A method of manufacturing an ultraviolet light emitting device having a group III-Nitride active layer containing an AlGaN alloy having nanometer-scale localized, self-assembled compositionally inhomogeneous regions characterized by having larger or smaller AlN mole fraction than the entire composition on average therein, said method comprising:

• depositing an active layer containing an AlGaN alloy on a substrate or a film layer formed adjacent a substrate using plasma-assisted molecular beam epitaxy,
• wherein the deposition of the active layer containing an AlGaN alloy is conducted under the following conditions:
• (a) deposition is performed under a facetted growth regime;
• (b) the substrate temperature is maintained within a temperature range of from about 770 to 950° C.
• (c) a nitrogen gas flow rate of from about 0.2 to 1.2 standard cubic centimeters per minute is maintained;
• (d) the active layer containing an AlGaN alloy is grown at a rate of about 80 to 1000 nm/hour;
• (e) the Al atom flux as measured by beam equivalent pressure is maintained at from about 1×10−8 to 2×10−7 Torr;
• and
• (f) the Ga atom flux as measured by beam equivalent pressure is maintained at from about 2×10−7 to 2×10−6 Torr,
• producing an ultraviolet light emitting device having an active layer containing an AlGaN alloy having nanometer-scale localized, self-assembled compositionally inhomogeneous regions characterized by having larger or smaller AlN mole fraction than the entire composition on average therein.