US 11,658,255 B1
Inverted metamorphic multijunction solar cell
Daniel Derkacs, Albuquerque, NM (US); Christopher Kerestes, Albuquerque, NM (US); and Steven Whipple, Albuquerque, NM (US)
Assigned to SolAero Technologies Inc., Albuquerque, NM (US)
Filed by SolAero Technologies Corp., Albuquerque, NM (US)
Filed on Nov. 10, 2020, as Appl. No. 17/94,110.
Application 17/094,110 is a division of application No. 16/037,378, filed on Jul. 17, 2018, granted, now 11,011,660.
Int. Cl. H01L 31/0687 (2012.01); H01L 31/18 (2006.01); H01L 31/0304 (2006.01); H01L 31/0224 (2006.01); H01L 31/0693 (2012.01)
CPC H01L 31/06875 (2013.01) [H01L 31/022425 (2013.01); H01L 31/03046 (2013.01); H01L 31/03048 (2013.01); H01L 31/0693 (2013.01); H01L 31/1844 (2013.01); H01L 31/1848 (2013.01); H01L 31/1892 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A multijunction solar cell comprising:
a window layer;
an upper or first solar subcell having a first band gap directly adjacent to and epitaxially grown on the window layer;
a second solar subcell adjacent to the upper or first solar subcell and having a second band gap smaller than the first band gap;
a grading interlayer disposed below, and adjacent to, the second solar subcell, wherein the grading interlayer has a third band gap throughout the thickness of the grading interlayer, the third band gap being greater than the second band gap; and
a third solar subcell disposed below the grading interlayer and lattice mismatched with respect to the second solar subcell, and having a fourth band gap smaller than the third band gap;
wherein the grading interlayer achieves a transition in lattice constant from the second solar subcell to the third solar subcell; and
wherein each of the window layer, the upper or first solar subcell, the second solar subcell, the grading interlayer and the third solar subcell comprises one or more epitaxial layers of an integrated semiconductor structure on a first side of a portion of a growth bulk semiconductor substrate, the portion of the growth bulk semiconductor substrate having a doping in the range of 1x1018 to 1x1020 charge carriers/cm 3,
the multijunction solar cell further including grid electrodes on a second side of the portion of the growth bulk semiconductor substrate, wherein the second side is on an opposite side from the first side.