Radial junction silicon wire array solar cells fabricated by gold-catalyzed vapor-liquid-solid growth

The fabrication of radial junction silicon (Si) solar cells using Si wire arrays grown by Au-catalyzed vapor-liquid-solid growth on patterned Si substrates was demonstrated. An important step in the fabrication process is the repeated thermal oxidation and oxide etching of the Si wire arrays. The oxidation cleaning process removes residual catalyst material from the wire tips and exposes additional Au embedded in the material. Using this cleaning process and junction formation through POCl₃ thermal diffusion, rectifying p-n junctions were obtained that exhibited an efficiency of 2.3% and open circuit voltages up to 0.5 V under Air Mass 1.5G illumination.