IBM researchers have produced a solar cell from inexpensive "earth abundant" materials:
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.”