Optoelectronic device

The present invention provides an optoelectronic device comprising a light source, an encapsulant with Refractive Index n1, and a phosphor with Refractive Index n2 which is within the range of from about 0.85n1, to about 1.15n1. The present invention also provides a method of adjusting the Refractive Index nx of a phosphor which is higher than a predetermined value n2. The method comprises partially or completely replacing one or more first element(s) in the phosphor with one or more second elements which typically have lower atomic weight than the first element(s). The phosphor is chemically stable and optically comparable with the encapsulant; and the optoelectronic device has gained technical merits such as increased light output efficiency, easy manufacturability, and cost-effectiveness, among others.