title: 17.6%-Efficient radial junction solar cells using silicon nano/micro hybrid structures.
abstract: We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm(2) exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm(-2) because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the proposed hybrid structure to become a foundational technology for the development of highly efficient radial junction solar cells.
authors.affiliation: Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea. kseo@unist.ac.kr.
authors.forename: Kangmin
authors.initials: K
authors.lastname: Lee
authors.forename: Inchan
authors.initials: I
authors.lastname: Hwang
authors.forename: Namwoo
authors.initials: N
authors.lastname: Kim
authors.forename: Deokjae
authors.initials: D
authors.lastname: Choi
authors.forename: Han-Don
authors.initials: HD
authors.lastname: Um
authors.forename: Seungchul
authors.initials: S
authors.lastname: Kim
authors.forename: Kwanyong
authors.initials: K
authors.lastname: Seo