Extrinsic doping of CuGaSe2 single crystals

Technological applications of semiconductors depend critically on the ability to dope them. Single crystals of CuGaSe2 were doped during crystal growth either by a post-growth diffusion step or by ion-implantation, in order to study the limits of extrinsic doping. The electrical and optical properties of the doped samples are analysed by Hall effect and photoluminescence (PL) measurements. The carrier concentration at room temperature can be adjusted between 2 x 10(19) cm(-3) (p-type) and 10(17) cm(-3) (n-type). Various donor and acceptor levels are identified and ascribed to dopant-induced point defects taking into account the dopant concentration and/or the post-growth treatment of the single crystals.