INFRARED LIGHT EMITTING DEVICE

摘要

Provided is an infrared light emitting device in which dark current and diffusion current caused by thermally excited holes are suppressed. Thermally excited carriers (holes) generated in a first n-type compound semiconductor layer (102) tend to diffuse in the direction of a n layer (105). But, the dark current by holes is reduced by providing an n-type wide band gap layer (103) with a larger band gap than the first layer (102) and the À layer (105) that suppresses the hole diffusion between the first layer (102) and the À layer (105). The wide band gap layer (103) has a band gap shifted relatively to valence band direction by n-type doping and thereby more effectively functions as a diffusion barrier for the thermally excited holes. Namely, the band gap and n-type doping of the wide band gap layer (103) are adjusted to suppress diffusion of the thermally excited carriers.