title: Realizing high-efficiency omnidirectional n-type Si solar cells via the hierarchical architecture concept with radial junctions.
abstract: Hierarchical structures combining micropyramids and nanowires with appropriate control of surface carrier recombination represent a class of architectures for radial p-n junction solar cells that synergizes the advantageous features including excellent broad-band, omnidirectional light-harvesting and efficient separation/collection of photoexcited carriers. The heterojunction solar cells fabricated with hierarchical structures exhibit the efficiency of 15.14% using cost-effective as-cut Czochralski n-type Si substrates, which is the highest reported efficiency among all n-type Si nanostructured solar cells. We also demonstrate the omnidirectional solar cell that exhibits the daily generated power enhancement of 44.2% by using hierarchical structures, as compared to conventional micropyramid control cells. The concurrent improvement in optical and electrical properties for realizing high-efficiency omnidirectional solar cells using as-cut Czochralski n-type Si substrates demonstrated here makes a hierarchical architecture concept promising for large-area and cost-effective mass production.
authors.affiliation: Institute of Photonics and Optoelectronics & Department of Electrical Engineering, National Taiwan University , Taipei 10617, Taiwan.
authors.forename: Hsin-Ping
authors.initials: HP
authors.lastname: Wang
authors.forename: Tzu-Yin
authors.initials: TY
authors.lastname: Lin
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Hsu
authors.forename: Meng-Lin
authors.initials: ML
authors.lastname: Tsai
authors.forename: Chih-Hsiung
authors.initials: CH
authors.lastname: Huang
authors.forename: Wan-Rou
authors.initials: WR
authors.lastname: Wei
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Huang
authors.forename: Yi-Jiunn
authors.initials: YJ
authors.lastname: Chien
authors.forename: Po-Chuan
authors.initials: PC
authors.lastname: Yang
authors.forename: Chee-Wee
authors.initials: CW
authors.lastname: Liu
authors.forename: Li-Jen
authors.initials: LJ
authors.lastname: Chou
authors.forename: Jr-Hau
authors.initials: JH
authors.lastname: He