I was under the impression that the problem with carbon nanotubes was actually structuring them on a wafer. If they can’t be reliably positioned and connected you get a lot of effectively random arcing. I’m sure doping is still useful, but I thought it wasn’t the core problem?

I’m biased as a structural biologist, but I’m pretty sure protein design approaches will eventually be used to facilitate proper placement. It’s not really high on my to-do list, so I suspect I’ll never get around to understanding the problem deeply enough to do it myself.