This work presents the investigation of MOVPE growth of silicon delta-doped GaAs and AlxGa1-xAs epilayers and different methods used for their characterisation. The influence of the growth temperature, Sil-L flow rate and AlxGa1-xAs composition on delta-doping characteristics is discussed. Properties of the Si delta-doped structures were examined using capacitance-voltage (C-V) measurements, photoreflectance spectroscopy, micro-photoluminescence, micro-Raman and photocurrent spectroscopies.