GERMANIUM-DOPED GALLIUM-PHOSPHIDE OBTAINED BY NEUTRON-IRRADIATION

Results of electrical, optical, electron spin resonance and optically detected magnetic resonance studies of thermal neutron irradiated and annealed at 800-degrees-C n-type GaP are presented. Evidence is found to support the view that the main dopant introduced via transmutation of GaP, germanium, occupies cation sites and forms neutral donors. Thi s confirms the possibility of neutron transmutation doping of GaP. Sim ultaneously, it is shown that germanium is absent at cation sites. Pre sence of other forms of Ge-related defects is deduced from luminescenc e and absorption data. Some of them are tentatively identified as V(Ga )-Ge(Ga) acceptors leading to the self-compensation process. This obse rvation means that the neutron transmutation as a doping method in app lication to GaP is not as efficient as for Si.