In solar cell research, the biggest recent breakthrough was probably the creation of efficient perovskite solar cells [1]. They're cheap, easy to make, and their efficiency in the lab is rising more rapidly than that of just about any other research cell since NREL began tracking (up from 3.5% in 2009 to 20.1% today) [2,3]. If their chemical stability problems can be resolved, they'll have big commercial applications.
Silicon never ceases to amaze me. While much of the research in solid state physics these days is around novel materials like graphene, silicon continues to dominate solid-state applications including all conventional computer processors and most solar cells and will prove incredibly hard to unseat in these areas. Now it appears to be a leading contender for quantum computing platforms. It's an earth-abundant material with billions of research dollars poured into it to support computing, so seeing progress in silicon quantum computing means real hope for applications.
Excerpt: "To a first approximation, a VC portfolio will only make money if your best company investment ends up being worth more than your whole fund." This is the big hit, and VC's are trying to optimize their chances of getting one of these. That's different from trying to precisely calculate expected return. As long as you've found it, it won't matter if you paid a bit too much.
So their computer does behave quantum mechanically. But I can't find any evidence that they have shown entanglement, which is necessary to realize the full promise of quantum computing, see e.g. http://www.scottaaronson.com/blog/?p=954#comment-40364
[1] http://www.sciencemag.org/content/342/6165/1438.2
[2] http://www.nrel.gov/ncpv/images/efficiency_chart.jpg
[3] http://www.technologyreview.com/news/517811/a-material-that-...