Silicon is a bitch. The equivalent doping density of silicon is something like the area of the United States, with 25 trees in it. Spread out, over the whole thing. That's what you target, and that's what we get because humans are awesome. But now we get something different. We get new materials that exhibit properties that we haven't seen before.
The nanotubes absorb IR. Awesome... transparent screens that make power (only at 1% efficiency, but it will get better). Still, there is a limit to how much power you can get if you're only able to absorb IR. So let's make it better, let's take Graphene (or nanotubes, although I'm not sure if they do it as well) and make the bandgap adjustable. It's like the "smart glass" (putting a voltage across a material 'scares' it into interacting with light differently) [1]. Now imagine we can do that with Graphene, but instead of just diffusing light, we can control when we absorb it. Put this on top of your tablet screen, when you're using the device, it is in IR mode, absorbing all the photons you can't see. When you shut it off, it starts absorbing all the visible photons, charging up your device. Put this material in your cars, keep the heat out of them in the summer while you charge your EV. On top of your house (although a plexiglas roof would be kind of scary).
The moment that we start being able to purchase the 'carbon train' is a great one. Technology is kind of a mixed feeling for me, it's so cool that we can talk to anyone, do anything (in imaginary land), but there isn't much environmental good that comes from it. Now you can use computers to do climate research or whatever, but we go out and grab the rarest materials to throw into our new fancy screens. Then we throw them away (eventually) when a newer, cooler one comes out. We are locking up all our of materials in electronic sarcophaguses that may never be separated again (at least until we get fusion and heat is free). I don't care how 'green' your laptop is, the amount of energy that went into making those teeny chips is absolutely ridiculous and I'm sure the 'energy footprint' of laptops is near the top of things we purchase. Carbon will change that though. It's plentiful. It's fast, it's new, it's sexy. It's different. We may need a little sprinkling of something special to make it really do what we want (hopefully not), but it's better in almost every way. It's going to blow our minds what the computers of tomorrow are capable of. Not because we know what's going to happen, but because the path we're headed down is going to be very, very rocky. It's time for a good electronic disruption.