Observation of multiple conduction paths in boron δ-doped diamond structures

Impedance spectroscopy has been used to investigate the conductivity displayed by diamond doped with boron in an intrinsic-delta doped-intrinsic multilayer system. For a 5nm thick delta layer, it is possible to observe three conduction pathways, which can be individually assigned to transport within the delta layer, and to two differing conduction paths in the i-layers adjoining the delta layer. For transport in the i-layers, thermal trapping and de-trapping processes can be observed, and only at the highest temperature investigated here (673K) can carrier transport due to a single conduction process be seen. Impedance spectroscopy is therefore an ideal nondestructive tool for investigating the electrical characteristics of complex diamond structures.