Article mentions gallium arsenide and very briefly issues with using it.
Anyway, research on alternatives to Silicon-based semiconductors comes up in the news every few years or so, and then vanishes again. Research may get some real funding at some point though, as eventually we're gonna run out of ways to get more mileage from Silicon base. Eventually. Probably. Just that there's so much invested into current that trying to catch anything else up for performance seems like a real risk with no guaranteed payout.
Article is a bit light on details. Might be nice to see the kinds of things that were mentioned in articles like this in The Times Before, such as comparisons of electron tunneling voltages, achievable clock speeds, feature sizes, lithography variants in use, feasibility of going 3d and stacking wafers compared to with current processes and so on and so on and so on and so ... ack.