21.5% Efficient thin silicon solar cell

Although many calculations since the early 1980s have predicted that high performance in thin crystalline silicon cells is feasible, performance levels demonstrated in the past have been quite modest, Using a self-supporting silicon membrane, experimental energy conversion efficiency above 20% is described for the first time for a silicon cell of less than 50 mu m thickness, with efficiency up to 21.5% independently confirmed for a 47-mu m thick device. The cells demonstrate a better ability to trap light internally within their structure than any previously measured device, They also demonstrate the surface passivation benefits of the recently described parallel multijunction thin-film silicon cell approach.