Gallium energy levels

There are five 3d orbitals available, all more or less of the same energy. Putting a pair of electrons in each of these five orbitals means that a total of ten electrons can be accommodated before we need to go to a higher energy level. Not only scandium but the nine following elements can be built up by adding electrons into 3d orbitals. Not until we get to gallium (element number 31) do we go up to another set of orbitals. 

FIGURE 4.13 Orbital energy level diagram for gallium arsenide. 

It was stated casually (page 275) that the energy levels of gallium are above those of germanium and, later, that those of arsenic lie below those of germanium. Can you provide any arguments, data, etc., to substantiate this ... 

The ionisation energies of the electronically active impurities have been determined primarily by photoluminescence techniques and Hall measurements. Ionisation energy levels of such impurities as nitrogen and some of the group III elements (aluminium, gallium, boron) in 3C-, 4H-, 6H- and 15R-SiC polytypes are compiled in TABLE 2. Nitrogen gives relatively shallow donor levels. In contrast, other p-type dopants have deep-level acceptor states. 

Valence electrons and period The energy level of an element s valence electrons indicates the period on the periodic table in which it is found. For example, lithium s valence electron is in the second energy levels and lithium is found in period 2. Now look at gallium, with its electron configuration of [Ar]4s 3d °4pb Gallium s valence electrons are in the fourth energy level, and gallium is found in the fourth period. 

Calculate the acceptor energy level position in gallium arsenide, GaAs, doped with zinc, using the Bohr model . The effective mass... 

Determine the energy of the n = 1 energy level in a fragment of n-type gallium nitride 20 nm X 393 nm x 1700 nm. The effective mass of electrons in this material is 0.19me. 

---