The two approaches are complementary: alone, neither achieves a complete description, but together, they offer good comparisons from which one may draw the firmest conclusions available regarding experimental devices. The second approach, dwelt upon in this work, also offers

descriptions of systems that should become available A-1210477 solubility dmso with improvements to the manufacturing processes mentioned above. As such, this is the focus of our discussion. Whilst single-monolayer studies converge properties by increasingly isolating the layers [11, 14, 16], at closer separations, it is impossible to divorce specific interactions between two layers from those between all of their (infinite) periodic replications. Further, effects arising due to atomic-scale mismatches in each layer’s doping locations cannot be seen when the neighbouring layer is a perfect replica. Building upon the methodology established whilst IWR 1 investigating single δ layers [16], expanded upon when

considering thicker layers comprised of multiple adjacent δ layers [19], and further GSK621 purchase extended to consider δ-doped nanowires [21], here, we model Si: δP bilayers, varying both their vertical separation (Figure 1a) and their relative in-plane alignment (Figure 1b). Figure 1 Model schematics. (a) Type-A bilayer system: tetragonal cell (lines), donors (P 1, P 2), periodic images (translucent circles), and effective donor Org 27569 layers (translucent sheets). Varying separation within bilayers (arrows). (b) Second-layer dopant (in-plane) positions: P 1 projection (black circle), coplanar Si atoms (circles), type-A, -B, and -C positions, other monolayers’ atoms’ projections (dashed circles), and periodic boundary (square). Methods δ layers of P are created on Si (001) terraces before being epitaxially coated with further Si [24–27]. It is easy to envision this coating process being monitored and halted at

a desired buffer thickness, before a new δ layer of P is created (and/or patterned). Single δ layer findings [16] suggest that layers interact when less than 80 monolayers (approximately 10.9 nm) of silicon separate them, and that at 80 ML, their properties converge with respect to silicon cladding depth. In that model, periodic replications of the layers were identical by construction, with no possibility of any deviation. Here, we explicitly allow for such differences by including a second layer in the model. c(2×2) cells including two δ-layers at N ML separation and 80 ML of Si cladding were built (N ∈ 4,8,16,40,60,80). Doping into a new layer can be accomplished at several locations [19]. For Nmod(4) = 0 systems, this can occur in three ways (Figure 1b): directly above the original dopant (type A), at either position nearest A in the plane (type B), or at maximal in-plane separation (type C).