Non-contacting spatially resolved measurements of Fermi energy and photoconductivity in semi-insulating undoped GaAs and InP:Fe

Variable temperature resistivity mappings have been conducted on samples of undoped gallium arsenide, grown by liquid encapsulated Czochralski (LEG), using a non-contacting electrical technique. These have been used to produce maps of the spatial variation of activation energy of conductivity. Insertion of a fibre optic into the electrode assembly has allowed non-contacting scanning photoconductivity measurements to be made. Preliminary results on semi-insulating InP:Fe are reported.