At Indium Corporation, we use indium metal to make many different forms, such as: wire, ribbon, and solder preforms. We also use it to produce various indium compounds. One of those indium compounds is indium trichloride (InCl3), which is an important material for making LEDs.
Indium trichloride isn't used directly though. It is a "precursor" component used to create TMI (tri-methyl indium). TMI is then deposited by chemical vapor deposition. Deposition techniques are discussed here: http://documents.indium.com/qdynamo/download.php?docid=1957
Here is a simple way to break down the path of indium into LEDs:
In + Cl --> indium (III) chloride --> TMI --> LED
If you'd like to learn more about how indium is used in the world around us, send an inquiry to me at jhisert@indium.com. I'm looking forward to it!
~Jim