An infrared-emitting diode has widely been used in infrared-ray communications, infrared remote controllers, light sources for various sensors, night lighting devices, and the like.
Known is the following light-emitting diode having a wavelength in the vicinity of the above described peak wavelength. That is the light-emitting diode manufactured such that a compound semiconductor layer including an AlGaAs active layer is epitaxially grown on a GaAs substrate (see, for example, Patent Literatures 1 to 3). Lately, the highest output infrared-emitting diode is a so-called substrate removal type light-emitting diode in which a GaAs substrate used as a growth substrate is removed and a compound semiconductor layer is structured only of a growth layer that is transparent with respect to the emission wavelength (see, for example, Patent Literature 4).
On the other hand, in a case of an infrared-ray communication used in transmission between devices, for example, an infrared lay having the emission wavelength in a range from 850 nm to 900 nm is used and, in a case of a communication via an infrared remote control, for example, an infrared ray having an emission wavelength in a range from 880 nm to 940 nm, the range being considered as a highly-sensitive waveband to be received by a light receiving portion, is used. The infrared-emitting diode having an emission peak wavelength in a range from 880 nm to 890 nm and using an AlGaAs active layer containing Ge as an effective impurity is known as the infrared-emitting diode capable of being used in both of the infrared-ray communication for terminal equipment, e.g., cellular mobile phone having functions of both of an infrared-ray communication and a communication via infrared remote control, and the communication via an infrared remote control (see, Patent Literature 4).
An infrared-emitting diode using an InGaAs active layer is known as the infrared-emitting diode that can have the emission peak wavelength of 900 nm or more (see, Patent Literatures 5 to 7).