Harnessing Carrier Multiplication in Silicon Solar Cells Using UV Photons

Silicon solar cells are known to suffer from poor emitter performance that is seen as reduced external quantum efficiency at wavelengths below 500 nm. This is due to common tradeoff between electrical and optical performance. Here we demonstrate that no such tradeoff is needed when optimized boron implantation parameters are combined with non-reflective nanostructures and atomic layer deposited Al ₂ O ₃ surface passivation. As a result, in our solar cells the external quantum efficiency actually increases with decreasing wavelength and reaches even above 100% at short wavelengths. This result indicates that carrier multiplication caused by absorption of high energy photons could be utilized for energy production in solar cells.