Understanding Energy Loss in a MOS Capacitor or MIS

[1msm]

Hello,

In a MOS capacitor or MIS after applying a voltage on the metal, the valence band and the conduction band bend downwards
(in the usual band diagram) when a positive voltage is applied. (p-type semiconductor).
When the voltage is large enough, electrons forms an inverse layer(green) with an energy level E1, as shown in below picture.

Now my question is,
How the electrons lost their energy by falling from higher conduction energy level (Ec) to lower inversion level E1.. ?

Thanks..

 

[BigJDubs]

When a positive voltage is applied, the electric field associated with that voltage creates an electric force that pushes the electrons from the conduction band (Ec) to the inversion layer (E1). This transfer of energy from the conduction band to the inversion layer is due to the work done by the electric field on the electrons. The electrons lose some of their energy in this process and thus fall from the higher conduction band energy level to the lower inversion layer energy level.