A very cool writeup. One of the low-temp effects that was missed: The semiconductor dopants (both donors and acceptors) don't necessarily fully ionize at liqu

A very cool writeup. One of the low-temp effects that was missed: The semiconductor dopants (both donors and acceptors) don't necessarily fully ionize at liquid nitrogen temps. So changing the electron/hole concentrations of silicon (for the electronics) or III-V (for the optics) can drastically alter the electronic properties. See, for example: http://ecee.colorado.edu/~bart/book/extrinsi.htm#freezout http://ecee.colorado.edu/~bart/book/extrinsi.htm#freezout