Solid state lighting (SSL) devices with improved contacts and associated methods of manufacturing are disclosed herein. In one embodiment, an SSL device includes an SSL structure having a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials. The SSL device also includes a first contact on the first semiconductor material and a second contact on the second semiconductor material, where the first and second contacts define the current flow path through the SSL structure. The first or second contact is configured to provide a current density profile in the SSL structure based on a target current density profile.

Solid state lighting (SSL) devices with improved contacts and associated methods of manufacturing are disclosed herein. In one embodiment, an SSL device includes an SSL structure having a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials. The SSL device also includes a first contact on the first semiconductor material and a second contact on the second semiconductor material, where the first and second contacts define the current flow path through the SSL structure. The first or second contact is configured to provide a current density profile in the SSL structure based on a target current density profile.

An epitaxial structure including a first epitaxial layer, a second epitaxial layer, and an interface treatment layer is provided. The first epitaxial layer is an ohmic contact layer. The second epitaxial layer is disposed on the first epitaxial layer and is a phosphide compound layer, where a material of the second epitaxial layer is different from a material of the first epitaxial layer. The interface treatment layer contacts the first epitaxial layer and the second epitaxial layer and is located between the first epitaxial layer and the second epitaxial layer. An image contrast ratio of a transmission electron microscope (TEM) of the interface treatment layer to the first epitaxial layer and an image contrast ratio of the TEM of the interface treatment layer to the second epitaxial layer are both greater than 1.005. A method for forming an epitaxial structure is also provided.

An epitaxial structure including a first epitaxial layer, a second epitaxial layer, and an interface treatment layer is provided. The first epitaxial layer is an ohmic contact layer. The second epitaxial layer is disposed on the first epitaxial layer and is a phosphide compound layer, where a material of the second epitaxial layer is different from a material of the first epitaxial layer. The interface treatment layer contacts the first epitaxial layer and the second epitaxial layer and is located between the first epitaxial layer and the second epitaxial layer. An image contrast ratio of a transmission electron microscope (TEM) of the interface treatment layer to the first epitaxial layer and an image contrast ratio of the TEM of the interface treatment layer to the second epitaxial layer are both greater than 1.005. A method for forming an epitaxial structure is also provided.

An epitaxial structure includes a first epitaxial layer, a second epitaxial layer, and an interface treatment layer. The second epitaxial layer is disposed on the first epitaxial layer. The interface treatment layer is located between the first epitaxial layer and the second epitaxial layer and is in contact with the first epitaxial layer and the second epitaxial layer. The first epitaxial layer, the second epitaxial layer, and the interface treatment layer include the same material. An image contrast ratio of a transmission electron microscope (TEM) of the interface treatment layer to the first epitaxial layer and an image contrast ratio of a TEM of the interface treatment layer to the second epitaxial layer are both greater than 1.005. A method for forming an epitaxial structure is also provided.

An optical semiconductor device includes: a mesa that is provided on a surface in a <011> direction of a semiconductor substrate having a (100) plane orientation and being of a first conductivity type, and includes a first cladding layer of the first conductivity type, an active layer, and a second cladding layer of a second conductivity type; a semi-insulating buried layer that buries both sides of the mesa, is provided on the semiconductor substrate, and includes a first region and a second region farther from the mesa than the first region; an insulation film provided on the first and second regions of the buried layer; and an electrode provided on the mesa and the insulation film on the first region; wherein a surface of the first region is at a height equal to or lower than a surface of the mesa, and lowers at farther distances from the mesa.

An optical semiconductor device includes: a mesa that is provided on a surface in a <011> direction of a semiconductor substrate having a (100) plane orientation and being of a first conductivity type, and includes a first cladding layer of the first conductivity type, an active layer, and a second cladding layer of a second conductivity type; a semi-insulating buried layer that buries both sides of the mesa, is provided on the semiconductor substrate, and includes a first region and a second region farther from the mesa than the first region; an insulation film provided on the first and second regions of the buried layer; and an electrode provided on the mesa and the insulation film on the first region; wherein a surface of the first region is at a height equal to or lower than a surface of the mesa, and lowers at farther distances from the mesa.

A device may include a metal contact between a first isolation region and a second isolation region on a first surface of an epitaxial layer. The device may include a first sidewall and a second sidewall on a second surface of the epitaxial layer distal to the first isolation region and the second isolation region. The device may include a wavelength converting layer on the epitaxial layer between the first sidewall and the second sidewall.

A device may include a metal contact between a first isolation region and a second isolation region on a first surface of an epitaxial layer. The device may include a first sidewall and a second sidewall on a second surface of the epitaxial layer distal to the first isolation region and the second isolation region. The device may include a wavelength converting layer on the epitaxial layer between the first sidewall and the second sidewall.

An organic EL element includes a pixel electrode, a light emitting function layer that is formed on the pixel electrode, an electron injection layer formed on the light emitting function layer, and a counter electrode that is formed on the electron injection layer and that has semi-transmissive reflectivity, in which the counter electrode contains a reductive material that reduces material of the electron injection layer and Ag with atomic ratio of 75% or more, and an adsorption layer is formed on the counter electrode.