Germanium (Ge) has a narrower bandgap (approx 0.7eV) compared with silicon, transistor in the earlier stages used Germanium mainly until much more stable silicon hit the market.

Even in modern days,Germanium is still used for diode due to the voltage dropping is low and used for light detecting application due to its bandgap is comparable narrow.
Besides, Germanium is also used for gamma radiation detector,infrared optical application and solar cell etc.

We supply 2inch ~ 4inch Germanium wafer for applications such like infrared,solar cell and detector.