US 12,336,321 B2
Photovoltaic devices with textured TCO layers, and methods of making TCO stacks
Paulina Bourgeois, Perrysburg, OH (US); Robert Clark-Phelps, Perrysburg, OH (US); Qi Fang, Perrysburg, OH (US); Jing Guo, Sunnyvale, CA (US); Gopal Mor, Perrysburg, OH (US); and Rui Shao, Sylvania, OH (US)
Assigned to First Solar, Inc., Tempe, AZ (US)
Appl. No. 17/279,254
Filed by First Solar, Inc., Tempe, AZ (US)
PCT Filed Sep. 23, 2019, PCT No. PCT/US2019/052370
§ 371(c)(1), (2) Date Mar. 24, 2021,
PCT Pub. No. WO2020/068630, PCT Pub. Date Apr. 2, 2020.
Claims priority of provisional application 62/735,328, filed on Sep. 24, 2018.
Prior Publication US 2022/0013674 A1, Jan. 13, 2022
Int. Cl. H10F 77/20 (2025.01); C03C 17/34 (2006.01); C23C 14/34 (2006.01); H10F 71/00 (2025.01); H10F 77/42 (2025.01); C23C 14/08 (2006.01)
CPC H10F 77/247 (2025.01) [C03C 17/3417 (2013.01); C23C 14/34 (2013.01); H10F 71/138 (2025.01); H10F 77/484 (2025.01); C03C 2217/232 (2013.01); C03C 2217/948 (2013.01); C03C 2218/154 (2013.01); C23C 14/086 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for manufacturing a thin film transparent conductive oxide layer stack for a photovoltaic device, comprising:
sputtering onto a substrate at least two transparent metal oxide layers in an inert sputtering environment, wherein the substrate comprises glass having a refractive index of about 1.5, and wherein one of the at least two transparent metal oxide layers comprises indium tin oxide (ITO), zinc magnesium oxide (ZMO), tin oxide (TO), or cadmium tin oxide (CTO);
controlling the inert sputtering environment with oxygen at a flow rate of from about 0.1 sccm to about 30 sccm to produce a sputtered transparent conductive oxide layer stack;
annealing the transparent conductive oxide layer stack; and
depositing an absorber layer on the transparent conductive oxide layer stack, the absorber layer comprising a p-type semiconductor material;
wherein the at least two transparent metal oxide layers define at least three interface regions between the substrate and the absorber layer, at least one of the interface regions having an average roughness greater than 5 nm, and refractive indices of the at least two transparent metal oxide layers are between 1.5 and 3, and the refractive index changes by no more than 0.5 at any of the interface regions; and
wherein the substrate temperature during sputtering is from about 300° C. to about 400° C.