A solar energy collecting system includes a substrate and at least one solar chip. The substrate includes a first surface, a second surface and a plurality of lateral surfaces, wherein the first surface faces the second surface, the lateral surfaces are adjacent to the first and second surfaces, and a first micro structure is formed on the first or the second surface. The solar chip is near one of the lateral surfaces. Solar light penetrates the first and the second surface and is refracted or reflected by the first micro structure to leave the substrate via the lateral surface and be absorbed by the solar chip.