The properties of n-type epilayers which had been grown onto (100) GaAs substrates by means of molecular beam epitaxy were reviewed with regard to photoluminescence, secondary ion mass spectroscopic and deep-level transient spectroscopic data. Great emphasis was placed on the effect of various dopants, and the role played by deviations from stoichiometry, upon doped epitaxial layers. Considerable attention was paid to the characterization and identification of deep-lying defect states; both the native ones and those introduced by dopants.

G.Karczewski, T.Wojtowicz: Acta Physica Polonica A, 1996, 90[4], 635-44