Investigation of p-BaSi2/n-Si heterojunction solar cells on Si(001) and comparison to those on Si(111)

Abstract

We grew boron-doped p-$BaSi_{\mathbf{2}}$ films with a hole concentration of $1.1\times 10^{\mathbf{18}} \mathbf{cm} ^{\mathbf{-3}}$ on a Si(001) substrate (resistivity ${\rho =1}-10 W \textbf{cm})$ by molecular beam epitaxy to form p-$BaSi_{\mathbf{2}}/n-Si$ heterojunction solar cells. The p-BaSi$BaSi_{\mathbf{2}}$ layer thicknesses (d) were varied from 20 to 60 nm to investigateits effect on solar cell performance. The conversion efficiency ($\eta$ increased with (d), reached a maximum of 9.8ñ at (d) =40 nm, and degraded for larger (d), indicating that Si(001) surface shows potential for $BaSi_{\mathbf{2}}$ solar cells. The results were compared with those on Si(111). Next, we will fabricate $BaSi_{\mathbf{2}}$ homojunction solar cells on Si(001).