Light emitting diode with fluorescent material
A light-emitting device can be configured to have little variation in light emission characteristics even at increased temperatures. A light-emitting device can include a light-emitting section for emitting light with a predetermined wavelength, and a fluorescent material for absorbing a part of light emitted from the light-emitting section and emitting light with a longer wavelength. The light-emitting device can mix the light with the predetermined wavelength from the light-emitting section and the light with the longer wavelength from the fluorescent material, and thereby emit a mixed light. The fluorescent material can include single crystal grains in which primary grains have a diameter of 1 μm or less. Crystal defects, such as a grain boundary, do not often and sometimes never occur in the single crystal grain having a diameter of 1 μm or less. Thus, it is possible to restrain a phenomenon in which a crystal defect non-radially emits absorbed energy (as heat) which then reduces light emission efficiency.
1. A light-emitting device comprising:
a light-emitting section for emitting light with a predetermined wavelength; and
a fluorescent material located adjacent the light emitting section and configured to absorb a part of light emitted from the light-emitting section and to emit light with a different wavelength, the fluorescent material including single crystal grains in which a grain boundary does not exist in primary grains of the single crystal grains.
2. The light-emitting device according to claim 1 , wherein
the fluorescent material includes secondary grains formed by the primary grains and having a diameter of 5 μm or more.
3. A light-emitting device comprising:
a substrate having a pair of electrodes;
a light-emitting section connected to the pair of electrodes and disposed adjacent the substrate, the light-emitting section configured to emit light with a predetermined wavelength;
a light conversion section formed adjacent the light-emitting section, the light conversion section including a fluorescent material, the fluorescent material configured to absorb at least a part of the light emitted from the light-emitting section and to convert the light into light with a longer wavelength, the fluorescent material including single crystal grains in which a grain boundary does not exist in primary grains of the single grain crystals.
4. The light-emitting device according to claim 3 , further comprising:
a reflecting section located adjacent the substrate so as to substantially surround the light-emitting section, the reflecting section configured to reflect the light emitted from the light-emitting section and the light from the light conversion section.
5. The light-emitting device according to claim 3 , wherein
the fluorescent material includes secondary grains formed by the primary grains and having a diameter of 5 μm or more.
6. The light-emitting device according to claim 3 , wherein the light conversion section surrounds the light emitting section.