Nichia Corporation

Ryota Funakoshi

Makoto Abe

Yoshitaka Kawata

A light-emitting element includes a first n-side semiconductor layer, a first active layer, a first p-side semiconductor layer, a second n-side semiconductor layer, a second active layer, and a second p-side semiconductor layer, each made of a nitride semiconductor. The second n-side semiconductor layer includes first to third layers. The first layer includes indium and gallium and has a first n-type impurity concentration. The second layer includes indium and gallium and has a second n-type impurity concentration less than the first n-type impurity concentration. A value of a composition ratio of indium in the second layer is less than a value of a composition ratio of indium in the first layer. A thickness of the second layer is greater than a thickness of the first layer. The third layer includes gallium and has a third n-type impurity concentration less than the second n-type impurity concentration.

Light-emitting element

A nitride semiconductor light-emitting element includes a first n-side semiconductor layer, a first active layer located on the first n-side semiconductor layer, a first p-side semiconductor layer located on the first active layer, a second n-side semiconductor layer located on the first p-side semiconductor layer, a second active layer located on the second n-side semiconductor layer, and a second p-side semiconductor layer located on the second active layer. The second n-side semiconductor layer has a tunnel junction with the first p-side semiconductor layer. The first active layer includes a first well layer and a first barrier layer alternately arranged in a stacking direction. The second active layer includes a second well layer and a second barrier layer alternately arranged in the stacking direction. The second well layer is thinner than the first well layer. The second barrier layer is thicker than the first barrier layer.

Nitride semiconductor light-emitting element

A method for manufacturing a light-emitting element includes forming a first light-emitting part, forming a tunnel junction part on the first light-emitting part, and forming a second light-emitting part on the tunnel junction part. The step of forming the first light-emitting part includes forming a first layer with a first p-type impurity concentration at a first temperature, and forming a second layer with a second p-type impurity concentration on the first layer. The second p-type impurity concentration is greater than the first p-type impurity concentration. The step of forming the second light-emitting part includes forming a third layer with a third p-type impurity concentration at a second temperature and forming a fourth layer with a fourth p-type impurity concentration on the third layer. The fourth p-type impurity concentration is greater than the third p-type impurity concentration. The second temperature is less than the first temperature.

Method for manufacturing light-emitting element

A nitride semiconductor element includes: a first light emission part that includes a first n-side semiconductor layer, a first active layer, and a first p-side semiconductor layer; a first layer that contains an n-type impurity of a first concentration, located on the first light emission part, and in contact with the first p-side semiconductor layer; a second layer that contains an n-type impurity of a second concentration, located on the first layer; and a second light emission part that includes a second n-side semiconductor layer located on the second layer, a second active layer, and a second p-side semiconductor layer. The second n-side semiconductor layer contains an n-type impurity of a third concentration. The first and second concentrations are higher than the third concentration. The first concentration is higher than the second concentration. A thickness of the second layer is larger than a thickness of the first layer.

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Tokushima, Japan

Ryota Funakoshi