US 12,062,732 B2
Solar cell structures for improved current generation and collection
Richard R. King, Thousand Oaks, CA (US); Christopher M. Fetzer, Valencia, CA (US); Daniel C. Law, Arcadia, CA (US); Xing-Quan Liu, Arcadia, CA (US); William D. Hong, Los Angeles, CA (US); Kenneth M. Edmondson, Burbank, CA (US); Dimitri D. Krut, Encino, CA (US); Joseph C. Boisvert, Thousand Oaks, CA (US); and Nasser H. Karam, La Canada, CA (US)
Assigned to THE BOEING COMPANY, Arlington, VA (US)
Filed by The Boeing Company, Chicago, IL (US)
Filed on Aug. 12, 2019, as Appl. No. 16/538,733.
Application 16/538,733 is a continuation of application No. 15/353,557, filed on Nov. 16, 2016, granted, now 10,439,091.
Application 15/353,557 is a continuation of application No. 13/831,056, filed on Mar. 14, 2013, granted, now 9,530,911, issued on Dec. 27, 2016.
Prior Publication US 2019/0378950 A1, Dec. 12, 2019
Int. Cl. H01L 31/044 (2014.01); H01L 31/0352 (2006.01); H01L 31/0687 (2012.01); H01L 31/0725 (2012.01); H01L 31/0735 (2012.01)
CPC H01L 31/0725 (2013.01) [H01L 31/0352 (2013.01); H01L 31/035209 (2013.01); H01L 31/035218 (2013.01); H01L 31/035227 (2013.01); H01L 31/035272 (2013.01); H01L 31/0687 (2013.01); H01L 31/0735 (2013.01); Y02E 10/544 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A multijunction optoelectronic device comprising:
a first photovoltaic cell;
a tunnel junction; and
a second photovoltaic cell comprising:
a space-charge region;
a quasi-neutral region;
a window layer;
an emitter layer adjacent the window layer;
a first portion of a base layer, the first portion of the base layer being at least partly in the space-charge region and further being one of a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer;
a second portion of the base layer having a higher bandgap than a bandgap of the first portion of the base layer, and
a back-surface-field (BSF) layer;
wherein the first portion of the base layer is disposed between the emitter layer and the second portion of the base layer, the second portion of the base layer being adjacent the BSF layer and adjacent the first portion of the base layer; and
wherein the tunnel junction electrically interconnects the first photovoltaic cell with the second photovoltaic cell in series, the BSF layer being disposed between the tunnel junction and the second portion of the base layer.