Fluorescent substance, method of manufacturing fluorescent substance, and light emitting device using the fluorescent substance

A method for manufacturing a europium-activated alkaline earth metal silicate fluorescent substance comprising:

• storing a mixture of raw materials into a vessel;
• applying a first baking to the mixture of the raw materials under a reducing gas atmosphere of N2/H2 so as to obtain a first baked material;
• pulverizing the first baked material to obtain a pulverized first baked material;
• storing the pulverized first baked material into a vessel;
• placing the vessel storing the pulverized first baked material in a furnace and substituting a nitrogen gas in the furnace under vacuum;
• and
• applying a second baking to the pulverized first baked material under a reducing gas atmosphere of N2/H2 having a hydrogen concentration of 1 to 100% so as to obtain a second baked material.

A light-emitting device comprising:

• a light-emitting element configured to emit a light having a wavelength of 360 nm to 500 nm, and
• a layer comprising a fluorescent substance formed on the light-emitting element, the fluorescent substance comprising an alkaline earth metal silicate having a composition represented by the following general formula (1):
• (Sr1-x-y-zBaxCayEuz)2SiwO2+2w (1)
• where x, y, z and w fall within the ranges of:
• 0≦x≦0.97;
• 0≦y≦0.97;
• 0.03≦z≦0.20;
• 1.00<w<1.10.