US 12,238,943 B2
Photovoltaic devices and method of making
Kristian William Andreini, Burnt Hills, NY (US); Holly Ann Blaydes, Perrysburg, OH (US); Jongwoo Choi, Boise, ID (US); Adam Fraser Halverson, Albany, NY (US); Eugene Thomas Hinners, Gansevoort, NY (US); William Hullinger Huber, Ottawa Hills, OH (US); Yong Liang, Niskayuna, NY (US); and Joseph John Shiang, Niskayuna, NY (US)
Assigned to First Solar, Inc., Tempe, AZ (US)
Filed by First Solar, Inc., Tempe, AZ (US)
Filed on Oct. 9, 2023, as Appl. No. 18/378,128.
Application 18/378,128 is a continuation of application No. 17/963,061, filed on Oct. 10, 2022, granted, now 11,784,278.
Application 17/963,061 is a continuation of application No. 17/466,708, filed on Sep. 3, 2021, granted, now 11,588,069, issued on Feb. 21, 2023.
Application 17/466,708 is a continuation of application No. 16/934,726, filed on Jul. 21, 2020, granted, now 11,164,989, issued on Nov. 2, 2021.
Application 16/934,726 is a continuation of application No. 16/200,423, filed on Nov. 26, 2018, granted, now 10,784,397, issued on Sep. 22, 2020.
Application 16/200,423 is a continuation of application No. 16/032,531, filed on Jul. 11, 2018, granted, now 10,141,473, issued on Nov. 27, 2018.
Application 16/032,531 is a continuation of application No. 13/912,782, filed on Jun. 7, 2013, granted, now 10,062,800, issued on Aug. 28, 2018.
Prior Publication US 2024/0055546 A1, Feb. 15, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 31/0224 (2006.01); H01L 31/0296 (2006.01); H01L 31/065 (2012.01); H01L 31/073 (2012.01); H10F 10/13 (2025.01); H10F 10/162 (2025.01); H10F 71/00 (2025.01); H10F 77/123 (2025.01); H10F 77/20 (2025.01)
CPC H10F 71/125 (2025.01) [H10F 10/13 (2025.01); H10F 10/162 (2025.01); H10F 71/1253 (2025.01); H10F 77/1237 (2025.01); H10F 77/211 (2025.01); Y02E 10/543 (2013.01); Y02P 70/50 (2015.11)] 20 Claims
OG exemplary drawing
 
1. A photovoltaic device, comprising:
a layer stack;
a back contact layer; and
an absorber layer disposed between the layer stack and the back contact layer, the absorber layer comprising a front interface and a back interface; wherein:
the absorber layer is an alloy comprising cadmium, tellurium, and selenium;
the absorber layer includes a varying concentration of selenium such that there is a higher concentration of selenium near the front interface relative to the back interface;
an atomic concentration of selenium varies non-linearly across a thickness of the absorber layer;
the absorber layer comprises a first region and a second region, the first region disposed proximate to the layer stack relative to the second region;
the first region has a thickness between 100 nanometers to 3000 nanometers;
the second region has a thickness between 100 nanometers to 3000 nanometers;
an average atomic concentration of selenium in the first region is greater than an average atomic concentration of selenium in the second region; and
a ratio of an average atomic concentration of selenium in the first region to an average atomic concentration of selenium in the second region is greater than 2.