The ionization energy for the pentavalent excess electrons in case of germanium is:

Ionization energy

Ionization energy is defined as the amount of energy required by an isolated gaseous atom to lose an electron in its ground state.

The ionization energy for the pentavalent excess electrons in the case of germanium is 0.0105 eV.

Types of semiconductor

1.) N-type semiconductor

• These types of semiconductors have an extra 1 electron, hence they donate one electron to doping material such as antimony in order to complete their octet, hence known as donor-type semiconductors.
• The majority of charge carriers are electrons and the minority of charge carriers are holes.
• Semiconductors such as germanium or silicon doped with pentavalent atoms such as antimony, phosphorous, or bismuth are called n-type semiconductors.

​2.) P-type semiconductor

• These types of semiconductors have a deficiency of 1 electron, hence they accept one electron from doping material such as boron in order to complete their octet, hence known as acceptor-type semiconductors.
• The majority of charge carriers are holes and the minority of charge carriers are electrons.
• Semiconductors such as germanium or silicon doped with trivalent atoms such as boron, indium, or gallium are called p-type semiconductors.