Donor atom

Donor atom

An impurity atom in a semiconductor which can contribute or donate one or more conduction electrons to the crystal by becoming ionized and positively charged. For example, an atom of column 5 of the periodic table substituting for a regular atom of a germanium or silicon crystal is a donor because it has one or more valence electrons which can be detached and added to the conduction band of the crystal. Donor atoms thus tend to increase the number of conduction electrons in the semiconductor. The ionization energy of a donor atom is the energy required to dissociate the electron from the atom and put it in the conduction band of the crystal. See Acceptor atom, Semiconductor

References in periodicals archive ?
5] fragments react quickly with any available donor atom to yield a M[(CO).
In summary (BROM-ANIS), (BROM-DMB) and (BROM-MB) behave as bidentate ligands via N-imine donor atom and amine nitrogen atom (attached with cyclohexyl ring of ligand) in complexes (1a)-(1c), (2a)-(2c) and (3a)-(3c) but (BROM-HB) and (BROM-o-VANI) behave as tridentate ligands via phenolic-O, imine-N and amine-N donor atoms in complexes (4a)-(4c) and (5a)-(5c).
When atoms of these two kinds interact, a re-arrangement of the electron distribution occurs; an electron from the donor atom migrates to the acceptor atom thereby making the acceptor atom negatively charged and the donor atom positively charged.
At the heart of coordination chemistry lies the coordinate bond, in its simplest sense arising from donation of a pair of electrons from a donor atom to an empty orbital on a central metalloid or metal.
These 16-electron M(CO)5 fragments react quicklywith any available donor atom to form a M[(CO).
1] in the free ligand, shifts to lower wavenumber in 1-18, showing that the ligands coordinate to metal via the imine donor atom.
3] ligands behave as a monodentate ligand via N imine donor atom in 1-9, but behaves as bidentate ligand via anionic O atom & imine N atoms in 10-18.
Forty sections treat ligand whose donor atoms come from a single group in the priodic table, ligands with mixed donors, and multidentate macrocyclic ligands.
Mixed donor atoms ligands arte subdivided into Schiff bases; amino acids, peptides, and proteins; complexones; and bidentate ligands.