Incorporation of optically active erbium into GaAs using the novel precursor tris(3,5-di-tert-butylpyrazolato)bis(4-tert-butylpyridine)erbium

We have investigated the use of an alternative erbium precursor, tris(3,5-d i-tert- butyl-pyrazolato)bis(4- tert-butylpyridine)erbium, to dope erbium i nto GaAs. The incorporated erbium forms an optically active center identifi ed as Er-2O. The GaAs: Er formed using this precursor exhibits sharper and more intense optical emission, attributed to the Er-2O center, than that pr eviously found with cylcopentadienyl-based erbium sources. Codoping GaAs: E r with shallow donors results in a quenching of the erbium-related luminesc ence, while codoping with shallow acceptors results in no significant chang e in the spectrum. Mechanisms for the observed luminescence-quenching behav ior are discussed. Deep level transient spectroscopy performed on silicon o r selenium codoped GaAs: Er showed the presence of several electron traps i n the upper half of the band gap. The origins of these electron traps are c onsidered. (C) 1999 American Institute of Physics. [S0021-8979(99)10903-4].