Patent ID: 7638809
Filing Date: 2009-12-29
Classification: H01L

Abstract:
1. A light emitting device comprising: a transparent substrate having a first surface and a second surface; a semiconductor layer provided on the first surface of the transparent substrate; a first light emission layer which is provided on the semiconductor layer and emits first ultraviolet light including a wavelength corresponding to an energy larger than a forbidden bandwidth of a semiconductor of the semiconductor layer; a second light emission layer which is provided between the first light emission layer and the semiconductor layer, absorbs the first ultraviolet light emitted from the first light emission layer, and emits second ultraviolet light including a wavelength corresponding to an energy smaller than the forbidden bandwidth of the semiconductor of the semiconductor layer; a first contact layer having a forbidden bandwidth wider than that of the first light emission layer and provided above the first light emission layer; a second contact layer provided below the second light emission layer; a first electrode provided on the first contact layer; and a second electrode provided on the second contact layer, the first electrode and the second electrode being able to apply electric power to the first light emission layer and the second light emission layer.