Spontaneous and stimulated emission devices based on relaxed III-nitride materials
Spontaneous and stimulated emission devices such as edge emitting laser diodes and vertical cavity surface emitting lasers operating in the visible spectrum and in the infrared spectrum between 380 mm and 1600 nm, and to the application of the light-emitting devices are disclosed. The devices are based on relaxed InGaN to provide strain-balanced epitaxial layer stacks.
1 . A vertical-cavity surface-emitting laser (VCSEL) device, wherein the VCSEL device comprises:
a III-nitride layer;
a first distributed Bragg reflector (DBR) stack overlying the III-nitride layer;
a relaxed In-containing III-nitride layer comprising a relaxed In-containing III-nitride surface, wherein the relaxed In-containing III-nitride layer underlies or overlies the first DBR stack;
an active region overlying the relaxed In-containing III-nitride layer; and
a second DBR stack overlying the active region;
wherein,
the active region comprises at least one In-containing III-nitride quantum well;
the active region is lattice matched to the relaxed In-containing III-nitride layer;
the relaxed In-containing III-nitride layer has an InN mole fraction greater than 0; and
the relaxed In-containing III-nitride layer has a single-phase gallium-polar (0001) orientation and a substantially relaxed in-plane a-lattice parameter.
2 . The VCSEL device of claim 1 , wherein the III-nitride layer comprises In x Al y Ga 1-x-y N wherein 0≤x≤1, 0≤y≤1, and x+y≤1.
3 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride layer comprises In x Al y Ga 1-x-y N, wherein 0<x≤0.4 and 0≤y≤1.
4 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride layer has a thickness greater than 100 nm.
5 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride layer has an in-plane a-lattice parameter greater than 3.20 Å.
6 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride layer comprises an In-containing III-nitride material and has a substantially relaxed in-plane a-lattice parameter that is within ±0.5% that of a fully relaxed in-plane a-lattice parameter of the In-containing III-nitride material.
7 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride surface is characterized by a root-mean-square surface roughness less than 1 nm over a 1×1 μm 2 area.
8 . The VCSEL device of claim 1 , wherein the relaxed In-containing III-nitride surface is characterized by a pit density less than 1×10 9 cm −2 , as determined by atomic force microscopy or electron microscopy.
9 . The VCSEL device of claim 1 , wherein
the VCSEL device comprises a first cladding layer underlying the active region and a second cladding layer overlying the active region;
the first cladding layer comprises a first dopant; and
the second cladding layer comprises a second dopant of opposite conductivity type to the first dopant.
10 . The VCSEL device of claim 9 , comprising a first electrode and a second electrode, wherein,
the first electrode is electrically connected to the first cladding layer; and
the second electrode is electrically connected to the second cladding layer.
11 . The VCSEL device of claim 1 , wherein the VCSEL device is configured to emit electromagnetic radiation with a dominant wavelength between 525 nm and 550 nm.
12 . The VCSEL device of claim 1 , wherein the VCSEL device is configured to emit electromagnetic radiation with a dominant wavelength between 600 nm and 640 nm.
13 . A wafer comprising the VCSEL device of claim 1 .
14 . A system comprising the VCSEL device of claim 1 .