Pictures By Alan

I've always kind of wondered which part of an LED actually emits the light. I took several pictures, and decided there is a portion of semiconductor mounted on the metal base; the semiconductor is sending out the light. The metal base has a peculiar shape, but I believe this has no function other than to make the orientation of the LED apparent. LEDs are polar devices, they won't work if installed the wrong direction.

In this picture, the top of the dome is glowing, but that's just a reflection. Lower, there's another reflection hovering above the actual light-emitting portion. The light is coming from a semiconductor wafer, which appears to be dish shaped and fixed to the top of the larger metal portion. Barely visible in this image are two tiny wires descending from the metal posts to the glowing semiconductor.

The metal posts are covered with bumps in a triangle pattern. I've no idea their function but it might simply be to anchor the metal in the plastic.