Hybrid Si microwire and planar solar cells: passivation and characterization.

We report an efficient hybrid Si microwire (radial junction) and planar solar cell with a maximum efficiency of 11.0% under AM 1.5G illumination. The maximum efficiency of the hybrid cell is improved from 7.2% to 11.0% by passivating the top surface and p-n junction with thin a-SiN:H and intrinsic poly-Si films, respectively, and is higher than that of planar cells of the identical layers due to increased light absorption and improved charge-carrier collections in both wires and planar components.