SL wells and NI wells. The black lines (solid and dashed) represent the potential barriers. The yellow-green colormap shows the energy resolved current $I_{ch}(E,x)$, with yellow corresponding to regions of large flow in the case of OP scattering. The blue lines represent the position of the Fermi level $E_F$. In (a) the red-solid line shows $\langle E ( x ) \rangle$ in the presence of AP only (i.e., elastic scattering), in which case charge carriers have constant energy above the barriers/wells. The magenta-dashed-dotted line shows $\langle E ( x ) \rangle$ in the presence of OP only (i.e., inelastic scattering), in which case carriers relax their energy in the regions between the barriers and absorb phonons to gain energy and overpass the barriers. The black-dashed line shows $\langle E ( x ) \rangle$ in the presence of AOP. In (b) the red-solid and magenta-dashed-dotted lines are the same as in (a) for the SL structure. The green-dashed and black-dotted lines show $\langle E ( x ) \rangle$ in the presence of AP and OP, respectively, for the SL+NIs structure. In (c) the red-solid line shows $\langle E ( x ) \rangle$ in the presence of AP, the magenta-dashed-dotted for OP, 