Epitaxial wafer for infrared light-emitting device and light-emitting device using the same

Abstract

The present invention provides an epitaxial wafer which is obtained by sequentially forming, on an n-type GaAs substrate, a first n-type GaAlAs layer; a second n-type GaAlAs layer; an n-type GaAlAs cladding layer; a p-type GaAlAs active layer which has an emission wavelength of 850-900 nm; and a p-type GaAlAs cladding layer, through liquid phase epitaxy, and, subsequently, removing the n-type GaAs substrate. In the epitaxial wafer, the p-type GaAlAs cladding layer has a thickness of 5-30 μm; the p-type GaAlAs cladding layer has an oxygen concentration of 3×1016 atoms/cm3 or less; the p-type GaAlAs cladding layer has a carrier concentration of 1×1017 cm−3 to 1×1018 cm−3; the p-type GaAlAs active layer has a thickness of 0.05-0.4 μm; the peak carbon concentration of the portion in the second n-type GaAlAs layer within 2 μm of the interface between the second n-type GaAlAs layer and the first n-type GaAlAs layer is less than 1×1017 atoms/cm3; the p-type GaAlAs active layer contains germanium as a predominant dopant; the n-type GaAlAs cladding layer has a Ge concentration of 3×1016 atoms/cm3 or less; and the second n-type GaAlAs layer has a Ge concentration of 3×1016 atoms/cm3 or less. The invention provides an epitaxial wafer of double-hetero structure for producing high-intensity GaAlAs infrared LEDs.

Dependencies are inferred from the claim text.