Transport properties of nanocrystalline silicon and silicon–germanium

We report on the minority carrier lifetime, diffusion length and mobility in nanocrystalline Si and (Si,Ge) p+nn+ devices. The devices were fabricated on stainless steel using VHF plasma deposition techniques. Minority carrier lifetime was measured using junction reverse recovery techniques. The minority carrier lifetime was found to be well correlated with the inverse of defect density and increased with increasing measurement temperature. Simultaneous measurement of diffusion length and lifetime yielded values for hole mobility.