Dear Physics forum users The below figure is from http://pubs.acs.org/doi/full/10.1021/jp0009305 In Fig. 3, energy band diagrams are shown for a semiconducting material inbetween two metal electrodes. The figure caption is: "Figure 3 Energy band diagrams for (a) p-type SiNW (b) n-type SiNW devices. The diagrams show schematically the effect of Vg on the electrostatic potential for both types of nanowires." Why do the bands bend in the way they do when applying a gate voltage V_g? Where can I find an explanation of this? Thanks for hints or pointing me out to references on this.