Week Eight - Semiconductor of the Week: Germanium

Discovered at the end of the 19th century, the semiconductor named after Germany was not very economically useful until the 1940s when it was used for transistors and diodes in electronics. However, it soon was replaced by by its more high quality semiconductor cousin, silicon. Although silicon is a higher quality choice for these uses, it is only so in a much purer state than germanium needs to be. To offset this trade-off in purity, though, it is worth noting that silicon's availability is only limited by its production, while germanium has limited availability in nature. So it seems to make sense to use silicon for these applications since it has better quality, even though you need more of it. 

Dollar for dollar comparison ten years ago: 

Silicon, 1 kg, $10.

Germanium, 1 kg, $1800

The question would be then, economically speaking, how MUCH more silicon do you need to equal germanium's efficacy? 

Germanium is still very valuable today for multiple infrared and optical uses such as thermal imaging for the military, night vision and fire fighting applications as well as fiber optics uses in cameras and microscopes.