Dual-layer solar cell developed at UCLA sets record for efficiently generating power | Malaysia

The title of the post is a copy and paste from the title and third paragraph of the linked academic press release here :

Dual-layer solar cell developed at UCLA sets record for efficiently generating power

The team’s new cell converts 22.4 percent of the incoming energy from the sun, a record in power conversion efficiency for a perovskite–CIGS tandem solar cell.

Journal Reference:

Qifeng Han, Yao-Tsung Hsieh, Lei Meng, Jyh-Lih Wu, Pengyu Sun, En-Ping Yao, Sheng-Yung Chang, Sang-Hoon Bae, Takuya Kato, Veronica Bermudez, Yang Yang.

High-performance perovskite/Cu(In,Ga)Se2 monolithic tandem solar cells.

Science, 2018; 361 (6405): 904

DOI: 10.1126/science.aat5055

Link: http://science.sciencemag.org/content/361/6405/904

Perovskite/CIGS tandem cells

Tandem solar cells can boost efficiency by using more of the available solar spectrum. Han et al. fabricated a two-terminal tandem cell with an inorganicorganic hybrid perovskite top layer and a Cu(In,Ga)Se2 (CIGS) bottom layer. Control of the roughness of the CIGS surface and the use of a heavily doped organic hole transport layer were crucial to achieve a 22.4% power conversion efficiency. The unencapsulated tandem cells maintained almost 90% of their efficiency after 500 hours of operation under ambient conditions.

Abstract

The combination of hybrid perovskite and Cu(In,Ga)Se2 (CIGS) has the potential for realizing high-efficiency thin-film tandem solar cells because of the complementary tunable bandgaps and excellent photovoltaic properties of these materials. In tandem solar device architectures, the interconnecting layer plays a critical role in determining the overall cell performance, requiring both an effective electrical connection and high optical transparency. We used nanoscale interface engineering of the CIGS surface and a heavily doped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) hole transport layer between the subcells that preserves open-circuit voltage and enhances both the fill factor and short-circuit current. A monolithic perovskite/CIGS tandem solar cell achieved a 22.43% efficiency, and unencapsulated devices under ambient conditions maintained 88% of their initial efficiency after 500 hours of aging under continuous 1-sun illumination.