Using radioactive isotopes of shallow dopants (Ag, As, Rb) as well as of na
tive or isoelectronic elements (Se, Te, Cd, Sr) which were incorporated as
host atoms and then transmuted into relevant dopants (transmutation doping)
we investigated doping phenomena occurring in the wide band gap II-VI comp
ounds CdTe, ZnTe, ZnSe and SrS by the classical methods of semiconductor ph
ysics: Hall effect, C-V and photoluminescence measurements. Thus, we could
assign unambiguously defect features in electrical and photoluminescence me
asurements to extrinsic dopants by means of the half lives of radioactive d
ecay. In As doped ZnSe samples we observed two states: a metastable effecti
ve mass like state and a deep state. The occurrence of the latter state is
always linked with the high resistivity of As doped ZnSe crystals. The tran
smutation doping experiments reveal that the so-called self-compensation ty
pical for wide band gab II-VI compounds can be overcome when the thermal tr
eatment for dopant incorporation is time separated from its electrical acti
vation, achieved using transmutation at room temperature. Under these condi
tions we found an almost one-to-one doping efficiency relative to the impla
nted dose. Thus, these investigations are a contribution to understanding c
ompensation phenomena occurring due to interactions between dopants and nat
ive defects during conventional doping treatments.