The Boeing Company

Peter E Gruenhaum

Lewis M Fraas

James E Avery

Veeravana S Sundaram

Eric Malocsay

Zinc diffusion procedures applicable for large scale manufacture of GaAs and GaSb cells used in tandem solar cells having a high energy conversion efficiency. The zinc doping and carrier concentration are restricted to be less than about 10.sup.19 /cm.sup.3 to obtain good light generated carrier collection and hence good short circuit currents. The amount of zinc that is available for diffusion during a drive-in heating step is restricted. Confinement of zinc and arsenic vapors during the heating step may be effected by use of a proximity source wafer or by an encapsulant layer. The zinc diffusion of GaSb is obtained by a homogeneous light diffusion that is followed by a patterned heavy diffusion to give low ohmic contact with the grid lines. Texture etching of the GaSb solar cell is also compatible with this diffusion process.

Growing community of inventors

Seattle, WA, United States of America

Peter E Gruenhaum