Band diagram
![The inner workings of a light emitting diode, showing circuit (top) and band diagram when under bias (bottom)](/Images/godic/202501/11/PnJunction-LED-E.svg5707.png")
![Band diagram for Schottky barrier at equilibrium.](/Images/godic/202501/11/Schottky_barrier_zero_bias.svg5707.png")
![Band diagram for semiconductor heterojunction at equilibrium.](/Images/godic/202501/11/Straddling_gap_heterojunction_band_diagram.svg5707.png")
In solid-state physics of semiconductors, a band diagram is a diagram plotting various key electron energy levels (Fermi level and nearby energy band edges) as a function of some spatial dimension, which is often denoted x. These diagrams help to explain the operation of many kinds of semiconductor devices and to visualize band bending.