[cbondurant]

Leaves me wondering if this will allow for superconducting cryogenic transistors? If my hobby level understanding of how silicon doping works, this new superconducting germanium would be a p-type? I could imagine something like ion implantation could be able to establish n-type regions within the germanium while allowing bulk regions of the lattice to maintain superconducting properties.

Though admittedly, I'm not actually aware what parts of a semiconductor circuit are the biggest power dissipation sources, so I guess its entirely possible that most of the power is dissipated across the p-n junctions themselves.

[sevensor]

Yes, this would be P type. Boron is usually the P type dopant of choice. I’m not sure what role they have in mind for this, but probably to replace polysilicon and metals as conductors. What you have to watch out for is that this will make diodes wherever it bumps up against n-type material. This is a problem for metals as well, because you can get accidental schottky junctions, and we usually solve it with degenerate doping under the contract. I’m not sure what a junction with this material would do though.

[pfdietz]

> Boron is usually the P type dopant of choice.

I want to note that in what has become the largest (by mass) application of semiconductors, silicon PV cells, boron has been replaced by gallium as the P type dopant of choice. Boron suffers from an annoying form of light-induced efficiency degradation that gallium avoids.