[@Kearney18], only NIs [@Fan11; @Ahmad16; @Liu12; @Foster17; @Peng14; @Zhou11], etc. In several cases, the conclusions vary substantially, from reports of large $PF$ benefits to only moderate or none; a consequence of the difficulty in accurately simulating and optimizing the complexity of geometries coupled with the complexities of the nanoscale transport physics in the presence of various types of nanostructured features. Indeed, the complexity of the electronic transport, combining semiclassical effects, quantum effects (i.e. quantization, tunneling, interferences, resonances), ballistic and diffusive regimes, as well as the geometry details with multiple features and feature types, makes accurate modelling a difficult task. Thus, it is imperative to shed more light and establish a high level of understanding of the $PF$ behavior in the presence of more than one nanoscale feature type, both qualitatively and quantitatively, if $ZT$ is to be maximized.

In this work we use the non-equilibrium Green’s Function (NEGF) method to calculate the electron transport properties of two-dimensional (2D) nanostructures when superlattice-type boundaries and NIs are present simultaneously (see Fig. 1). NEGF provides a unified, geometry flexible, fully quantum mechanical simulation approach well-suited for this problem. We present a systematic investigation of how such complex geometries affect the $PF$ in the 