And It's Pretty Efficient Too!
IBM researchers has recently published a paper in the journal Advanced Materials about a very promising breakthrough in solar technology. What makes it a breakthrough compared to existing solar technologies (such as silicon-based solar cells, or CIGS thin film)? The fact that it's made from earth abundant materials that can be found in large quantities relatively inexpensively (not quite dirt cheap, but cheaper than what we have now).
Magnified view of a cross section of the compound Cu2ZnSn(S,Se)4 Image: IBM

The layer that absorbs sunlight to convert it into electricity is made with Copper (Cu), Tin (Sn), Zinc (Zn), Sulfur (S) and/or Selenium (Se). This is pretty abundant compared to the Copper (Cu), Indium (In), Gallium (Ga), and Selenium (Se) that GIGS thin film cells use.

The beauty is that it has a "conversion efficiency of 9.6 percent, which is 40 percent higher than previous attempts to create a solar cell made of similar materials." But this is just a start. More improvements to power conversion should be possible.

IBM says that it "does not plan to manufacture solar technologies, but is open to partnering with solar cell manufacturers to demonstrate the technology." Let's hope that this can be moved out of the lab quickly.

Now how about working on cheaper and efficient ways to store large quantities of energy? That's the missing half of the puzzle that would make solar power more practical on the very large scale.