Fermi level shift, statistical

The use of experimental physics and the implementation of new theoretical concepts and methods from solid-state physics or statistical mechanics to electrochemistry contributed to the development of surface electrochemistry. This was particularly important for a better understanding of the electric double layer or, more generally speaking, of the solvent structure near a charged metal (by shifting the Fermi level upward or downward). Important results came from computer simulations of the electric double layer that yielded new information about the spatial distribution of ions and water molecules toward the electrode surface [30]. 

For a semiconductor laser, a key requirement is the possibility of obtaining a population inversion between the conduction and valence bands. In this case, one must have materials with an excess density of electrons in the conduction band and holes in the valence band. One can achieve this excess in semiconductor materials by doping the material with donor or acceptor atoms, for n- and / -type materials, respectively. By doping the semiconductor, the effect is to modify the probability statistics by shifting the Fermi function to a new Fermi level. Figure 5 shows the carrier concentration for n- and />-type doped semiconductors. 

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