Solar Cell Efficiency Round-Up: Thin Film Closing the Gap with Silicon

By James Montgomery, Associate Editor, RenewableEnergyWorld.com
January 25, 2013 

 

New Hampshire, USA -- A flurry of new solar-cell efficiency records — including a quiet surprise — are putting thin-film solar PV technologies tantalizingly close to silicon rivals.

The latest results (except Empa, which is awaiting official confirmation from the overseas lab) are in NREL's updated multistrand chart (below) and in the solar cell efficiency tablespublished by Progress in Photovoltaics. 

CdTe: 18.3 percent. There's a new record holder in thin-film cadmium telluride (CdTe): GE Research is now on top with an 18.3 percent efficient cell, a full percentage point higher than the 17.3 percent mark achieved by First Solar last year. In the world solar cell efficiency ladder where fractions of a percent improvements are typical, a full point improvement is actually pretty remarkable — but maybe not a surprise. GE has been building on the CdTe technologyit acquired from PrimeStar, and believes the technology "hasn't really been explored as much as it could be," said Anil Duggal, GE Research's solar technology platform leader. Three years ago "we were making 10 percent cells," he said; their internal goal is to match the ~20 percent efficiency of today's multicrystalline silicon cells. Duggal wouldn't describe the specifics of GE's CdTe process or what it tweaked to raise the efficiency bar, except to say that it was an equal achievement between work on the materials, device design, and processing. He also noted that GE is already evaluating how the new cell performs on a pilot line, and that the goal is CdTe modules with ~15 percent efficiencies.