Manufacturing method of phosphor precursor

A method for manufacturing a phosphor precursor by using a mixing device comprising:

• (a) at least one first inlet flow passage;
• (b) at least one second inlet flow passage, the first inlet flow passage and the second inlet flow passage connect together so as to form a collision section;
• and
• (c) an outlet flow passage which is connected with the collision section,
• the method comprising the steps of:
• (i) supplying continuously a first raw phosphor material solution into the first inlet flow passage and a second raw phosphor material solution into the second inlet flow passage;
• (ii) introducing the first raw phosphor material solution and the second raw phosphor material solution into the collision section so as to mix with each other and to form a phosphor precursor;
• and
• (iii) releasing continuously the phosphor precursor from an exit of the outlet flow passage with controlling a flow of the phosphor precursor so as to keep a Reynolds number of the phosphor precursor to be not less than 3000 while retaining the phosphor precursor in the outlet flow passage for not less than 0.001 seconds.