Engineering topics

Rao, C. V. H.

Publications and source records attributed to Rao, C. V. H..

3 records

NASA NTRS1978

Large area silicon sheet by EFG

The edge-defined, film-fed growth (EFG) technique has been employed to grow silicon ribbons for photovoltaic applications. Considerable progress has been made in recent years in developing the technique to the point that long lengths of silicon ribbon can be routinely grown. In order to attain the full low-cost potential of the EFG technique, several further developments such as the growth of thinner and wider ribbons, increase in ribbon growth rate, and improvements in material quality are needed. The technological problems to be solved and the approaches employed to achieve these goals are discussed.

Rao, C. V. H.↗

NASA NTRS1976

Orientation dependence of defect structure in EFG silicon ribbons

Sustained growth of long lengths of silicon ribbons by the edge-defined film-fed growth (EFG) technique is shown to result in the attainment of an 'equilibrium' defect structure and orientation by the crystals. The structure consists of parallel defect boundaries parallel to the edges of the ribbon with a specific ribbon orientation. The influence of seed orientation on the attainment of this structure has been examined.

Garone, L. C.↗

NASA NTRS1976

Large area silicon sheet by EFG

Progress in a program to produce high speed, thin, wide silicon sheets for fabricating 10% efficient solar cells is reported. An EFG ribbon growth system was used to perform growth rate and ribbon thickness experiments. A new, wide ribbon growth system was developed. A theoretical study of stresses in ribbons was also conducted. The EFG ribbons were observed to exhibit a characteristic defect structure which is orientation dependent in the early stages of growth.

Morrison, A. D.↗