Boron-doped p-BaSi2/n-Si solar cells formed on textured n-Si(0 0 1) with a pyramid structure consisting of {1 1 1} facets

BaSi₂ films were fabricated on textured Si(0 0 1) substrates that consisted of {1 1 1} facets using molecular beam epitaxy. The light-trapping effect of these films and their performance when incorporated into solar cells were measured. X-ray diffraction and reflectivity measurements showed that the BaSi₂ films were grown epitaxially on the textured Si(0 0 1) substrate and confirmed the light-trapping effect. The critical thickness over which BaSi₂ relaxes increased from approximately 50 to 100 nm when comparing the BaSi₂ films on a flat Si(1 1 1) substrate and the textured substrate, respectively. p-BaSi₂/n-Si solar cells were fabricated with varying BaSi₂ layer thickness and with hole concentrations in the range between 2.0 × 10¹⁸ and 4.6 × 10¹⁸ cm^-3. These cells exhibited a maximum energy conversion efficiency of 4.62% with an open-circuit voltage of 0.30 V and a short-circuit current density of 27.6 mA/cm² when the p-BaSi₂ layer was 75 nm-thick. These results indicated that the use of BaSi₂ films on textured Si(0 0 1) substrates in solar cells shows great promise.