Persistent ion beam induced conduction in semiconductor nanowires

The electrical conductance of single, semiconductor nanowires is investigated in-situ during ion beam exposure. A stark increase in conductance proportional to ion flux and ion energy is observed. The increase in conductance shows remarkable similarities to the persistent photoconduction effect (PPC), which is well known yet not comprehensively understood. Especially ZnO nanowires show a strong increase in conductance (photo and ion induced) that only decays over days. Experiments are performed to investigate the parallels between ion and photo induced conductivity and to examine the underlying mechanisms. The decay rate is very sensitive to the external environment so that surface effects are considered to cause the conduction enhancement.