- #1
PainterGuy
- 940
- 69
hi everyone,
when antimony is added to germanium, antimony's atoms make covalent bonds with germanium. antimony has five valence electrons and germanium has four. there would be total 4 covalent bonds each consisting of 2 electrons. this would mean that there would be one extra from each antimony's atom hence only four electrons are used to make covalent bonds with germanium atoms. that's what n-type semiconductor is.
now suppose indium, with three valence electrons, is added to germanium atoms. before indium was added to germanium, atoms of germanium were covalently bonded to each other. each atom of germanium making 4 covalent bonds with other germanium atoms. now when indium is added, three out four covalent bonds of each germanium atom will break to form new covalent bonds with indium atoms because indium has only three valence electrons to form three covalent bonds. you see there is still one covalent bond remaining for each germanium atoms, which means all the electrons are used up. no electron is free and neither there is any deficiency of electrons. in other words no holes are there. where am i going wrong? any idea. any help would be welcome.
cheers
when antimony is added to germanium, antimony's atoms make covalent bonds with germanium. antimony has five valence electrons and germanium has four. there would be total 4 covalent bonds each consisting of 2 electrons. this would mean that there would be one extra from each antimony's atom hence only four electrons are used to make covalent bonds with germanium atoms. that's what n-type semiconductor is.
now suppose indium, with three valence electrons, is added to germanium atoms. before indium was added to germanium, atoms of germanium were covalently bonded to each other. each atom of germanium making 4 covalent bonds with other germanium atoms. now when indium is added, three out four covalent bonds of each germanium atom will break to form new covalent bonds with indium atoms because indium has only three valence electrons to form three covalent bonds. you see there is still one covalent bond remaining for each germanium atoms, which means all the electrons are used up. no electron is free and neither there is any deficiency of electrons. in other words no holes are there. where am i going wrong? any idea. any help would be welcome.
cheers