[dotnet00]

I agree regarding photonic transistors, I have a hard time seeing how those would scale down to even current transistor sizes/densities. Especially given that they'd probably have to rely on much shorter wavelength light, which comes with its own issues.

Carbon Nanotube transistors are fairly promising though, they're structured similarly to regular transistors but can have some neat properties like ballistic transport regimes (meaning zero resistance when enough current is going through), better heat dissipation and ability to handle much higher currents. IIRC they're also very tunable with the bandgap controlled by the shape of the tube.

Main issue with CNT transistors is just that - as with most things involving CNTs - we need production methods that are significantly more consistent with the shape and quality of tube they produce. We'd need to be able to print billions of tubes per chip with almost the exact same shape to compete with traditional semiconductors.