SiC FLUORESCENT MATERIAL AND LIGHT EMITTING DIODE

摘要

[PROBLEMS] To provide an SiC fluorescent material and a light emitting diode which can achieve high energy conversion efficiency. [MEANS FOR SOLVING PROBLEMS] Fluorescence quantum efficiency strongly depends on acceptor impurity concentration, and to obtain a 70% or higher fluorescence quantum efficiency, an acceptor impurity concentration of 5×10¹⁷cm^-3 or more is required. When the acceptor impurity concentration exceeds a donor impurity concentration, the fluorescence quantum efficiency drastically reduces. Therefore, the acceptor impurity concentration is set lower than the donor impurity concentration. Furthermore, in a SiC single crystal, when the donor impurity concentration exceeds 10¹⁹cm^-3, the crystal quality drastically deteriorates. Therefore, the donor impurity concentration is set at 10¹⁹cm^-3 or less.