Study on optical properties of reactive-sputtering a-Si:H/a-Ge:H superlattices

The structural characteristics of a-Si:H/a-Ge:H superlattices prepared by reactive-sputtering method are studied. Transmission electron microscopy (TEM) and small angle X-ray diffraction measurements demonstrate that the superlattice layers are parallel and uniform with atomically sharp interfaces and good periodicity. In Raman, IR, and optical absorption spectrum measurements, no indication of excess structure disorder associated with the superlattice and no evidence of excess H at the a-Si:H/a-Ge:H interface are found.