Demonstration of B-ion-implanted p-BaSi2/n-Si heterojunction solar cells

The implantation of B atoms into BaSi2 epitaxial films grown by molecular beam epitaxy was performed to form p-type BaSi2 films. It was revealed by Raman spectroscopy that the ion-implantation damage induced in the implanted BaSi2 films was recovered by post-annealing at 600 degrees C or higher temperatures for 64 min. The hole concentration increased up to 3.1 x 10(18) cm(-3) at room temperature, indicating that B-ion-implanted p-BaSi2 films are applicable as a hole transport layer. The B-ion-implanted p-BaSi2/n-Si heterojunction solar cells showed rectifying current-voltage characteristics under AM1.5 G illumination and the internal quantum efficiency reached 72% at the wavelength of 900 nm. The conversation efficiency was 2.2%. These results open new routes for the formation methods of BaSi2 solar cells.