The following uses for germanium are gathered from a number of sources as well as from anecdotal comments. I'd be delighted to receive corrections as well as additional referenced uses (please use the feedback mechanism to add uses).
- doped with arsenic, gallium, or other elements for use as a transistor element. Its application as a semiconductor provides the largest use for germanium
- alloying agent
- phosphor in fluorescent lamps
- a catalyst
- germanium and germanium oxide are transparent to the infrared and are used in infrared spectroscopes and other optical equipment, including extremely sensitive infrared detectors. Also for wide-angle camera lenses and microscope objectives.
- possible chemotherapy applications?
- use as a gamma-radiation detector