Donor identification in bulk gallium arsenide.

We report the first identification by any spectroscopic method of shallow donors in bulk gallium arsenide. Identification is achieved using photoluminescence from resonantly excited two electron satellites of donor bound exciton lines at 4.2K in a magnetic field of 9.5 Tesla. 

Sulphur and a previously unreported lower binding energy donor dominate in liquid encapsulated Czochralski grown crystal, while S and Si are dominant in Bridgman grown material. Central cell structure is resolved in the (D degree, X) lines in high magnetic field.