Nitride semiconductor light-emitting element

Abstract

Provided is a nitride semiconductor deep ultraviolet light-emitting element having exceptional light-emitting efficiency. A nitride semiconductor light-emitting element having a light-emission wavelength of 200-300 nm, wherein said element has an n-type layer comprising a single layer or a plurality of layers with differing bandgaps, a p-type layer comprising a single layer or a plurality of layers with differing bandgaps, and an active layer arranged between the n-type layer and the p-type layer. The p-type layer has a p-type first layer having a bandgap that is larger than the bandgap of the n-type first layer having the smallest bandgap within the n-type layer. An electron block layer is provided between the active layer and the p-type first layer, the electron block layer having a bandgap that is larger than the bandgaps of any of the layers forming the active layer and the p-type layer.

Description

technical field [0001] The present invention relates to a novel deep ultraviolet light-emitting element using a nitride semiconductor with a light-emitting wavelength in the range of 200-300nm. Background technique [0002] Currently, a gas light source such as deuterium or mercury is used as a deep ultraviolet light source having an emission wavelength of 300 nm or less. These gas light sources have disadvantages such as short lifetime and large size. In addition, mercury is a substance restricted by the treaty. Therefore, realization of a deep-ultraviolet light-emitting element using a semiconductor that eliminates these inconveniences and is easy to handle has been desired. [0003] However, light-emitting elements using semiconductors have problems of weaker light output and lower luminous efficiency than gas light sources such as deuterium gas lamps and mercury gas lamps. [0004] As the cause of insufficient light output of the semiconductor light-emitting element, ...

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Problems solved by technology

[0003] However, light-emitting elements using semiconductors have problems of weaker light output and lower luminous efficiency than gas light sources such as deuterium gas lamps and mercury gas lamps.

[0004] As the cause of insufficient light output of the semiconductor light-emitting element, it can be cited that in the nitride semiconductor light-emitting element, the effective mass of electrons is small compared with holes, and the carrier concentration is high, so that electrons pass through the active layer ( region), overflowing to the p-type layer, resulting in a reduction in luminous efficiency

The overflow of electrons to the p-type layer leads to a further decrease in luminous efficiency and an increase in heat generation under high injection current conditions.

As a result, the light output reaches a limit, and it is difficult to obtain a light output corresponding to the amount of injected carriers.

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