No deposit, no return.

UNSW researchers have devised a way to deposit a thin film of silver (about 10 nanometres thick) onto a solar cell surface and then heat it to 200° Celsius. This breaks the film into tiny 100-nanometre "islands" of silver that boost the cell’s light trapping ability, thereby boosting its efficiency. . .

"Most thin-film solar cells are between eight and 10 percent efficient," says Dr Kylie Catchpole, a co-author of the study, "but the new technique could increase efficiency to between 13 and 15 percent." . . .

[R]esearchers . . . have reported a 16-fold enhancement in light absorption in 1.25-micron thin-film cells for light with a wavelength of 1050 nm. They have also reported a seven-fold enhancement in light absorption in the more expensive wafer type cells light wavelengths of 1200 nm.

Though this is a solar energy story I was struck by the nano nano aspect. It seems that we continue to gain very useful capabilities as a consequence of increased facility at ever smaller scales. Our stuff is big, clunky and inefficient now, but as we get smaller and neater even old tech works better.