Structural, electrical and recombination properties of Be-doped low-temperature MBE grown (LTG) GaAs have been investigated by using a number of different experimental techniques. These properties were analysed with respect to the applications of LTG GaAs in ultrafast optoelectronic devices. It has been found that a moderate Be-doping improves the structural quality of the layers and does not affect their semi-insulating behaviour. Electron and hole capture cross-sections, critical parameters for the design of optoelectronic devices from LTG GaAs, equal to sigma(n) = 1.1 x 10(-13) and sigma(p) = 1.8 x 10(-15) cm(2) were also determined.