NEW DONOR DOPING SOURCES FOR MOLECULAR-BEAM EPITAXY OF ALGASB AND ALGAAS

Results obtained for the first time using Ga2S3 and Ga2Se3 compounds a s sources of donor elements for the molecular beam epitaxy of AlxGa1-x Sb (0 less than or equal to x less than or equal to 1) and AlxGa1-xAs (0 less than or equal to x less than or equal to 0.4) are reported. In GaAs, free electron concentrations obtained when incorporating the do nors from these sources can be readily controlled up to a maximum of 5 x 10(18) cm(-3). For AlxGa1-xSb it was possible to compensate the hig h concentration of native acceptors and obtain n type conductivity ove r the full composition range of the alloy. In AlxGa1-xSb donor related defects (DX centres) were observed. (C) 1996 The Institute of Materia ls.