Hall-effect and sign properties in hydrogenated amorphous and disordered crystalline silicon

Hall experiments on a series of microcrystalline, microcrystalline-amorphous, amorphous and crystalline silicon samples with varying defect densities are presented and discussed. Normal Hall effect signatures on boron and phosphorus doped hydrogenated amorphous silicon are detected. We interpret these results to be due to a small volume fraction of nanocrystalline Si, which falls below the detection limits of Raman experiments. Hydrogenated amorphous silicon, prepared under conditions far away from microcrystalline growth, shows the known double sign anomaly. Sign reversals in c-Si, where the disorder is increased by Si implantation up to very high levels, could not be detected.