LIGHT-EMITTING DEVICE

摘要

Disclosed is a light-emitting device wherein light in the visible to ultraviolet region can be taken out from the substrate side by using a Ga<SUB>2</SUB>O<SUB>3</SUB> substrate and the substrate-side outcoupling efficiency is excellent. In this light-emitting device, increase in current density is suppressed. Specifically disclosed is a light-emitting device which is characterized by comprising a Ga<SUB>2</SUB>O<SUB>3</SUB> substrate, and an epitaxial layer formed on the Ga<SUB>2</SUB>O<SUB>3</SUB> substrate and having recessed and projected portions. Due to the recessed and projected portions, light emitted from the active layer is reflected in various directions to the Ga<SUB>2</SUB>O<SUB>3</SUB> substrate, thereby suppressing total reflection by the Ga<SUB>2</SUB>O<SUB>3</SUB> substrate interface and improving the outcoupling efficiency.