27-10-2012, 11:55 AM
Experimental Studies of Light-Induced Changes in Long-Ranged Disorder in Amorphous Silicon
ABSTRACT
The principal objective of the proposed research is the experimental study and elucidation of the role that long ranged
disorder plays in the light-induced metastable conductance changes in hydrogenated amorphous silicon (a-Si:H). The
development of sources of low-cost renewable electrical energy is a high National priority. A consensus has developed that
hydrogenated amorphous silicon (a-Si:H) is the material of choice for large-area photovoltaic devices. However, the efficiency
of a-Si:H based solar cells decreases by nearly a factor of two following extended illumination, owing to the creation of
light-induced defects resulting from the recombination of photo-excited charge carriers. If this light-induced defect formation
could be reduced or eliminated, the practical conversion-efficiency of a-Si:H based solar cells would effectively double,
yielding cost per kilowatt-hour values comparable to that of conventional fossil fuel generation of electricity.