One third of a monolayer of spatially ordered B on (111)-oriented crystalline Si was prepared under ultra-high vacuum and then buried under a thin layer of amorphous Si. This left a 2-dimensional v3 x v3 B layer in substitutional sites which were confined to a single monolayer on the crystalline side of the interface. This layer was electrically active, with a mobility that was greater than the corresponding bulk value.

R.L.Headrick, A.F.J.Levi, H.S.Luftman, J.Kovalchick, L.C.Feldman: Physical Review B, 1991, 43[18], 14711-4