title: Effects of formation of mini-bands in two-dimensional array of silicon nanodisks with SiC interlayer for quantum dot solar cells.
abstract: A sub-10 nm, high-density, periodic silicon nanodisk (Si-ND) array with a SiC interlayer has been fabricated using a new top-down process that involves a 2D array of a bio-template etching mask and damage-free neutral beam etching. Optical and electrical measurements were carried out to clarify the formation of mini-bands due to wavefunction coupling. We found that the SiC interlayer could enhance the optical absorption coefficient in the layer of Si-NDs due to the stronger coupling of wavefunctions. Theoretical simulation also indicated that wavefunction coupling was effectively enhanced in Si-NDs with a SiC interlayer, which precisely matched the experimental results. Furthermore, the I-V properties of a 2D array of Si-NDs with a SiC interlayer were studied through conductive AFM measurements, which indicated conductivity in the structure was enhanced by strong lateral electronic coupling between neighboring Si-NDs. We confirmed carrier generation and less current degradation in the structure due to high photon absorption and conductivity by inserting the Si-NDs into p-i-n solar cells.
authors.affiliation: Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 9808577, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Igarashi
authors.forename: Mohd Fairuz
authors.initials: MF
authors.lastname: Budiman
authors.forename: Wugen
authors.initials: W
authors.lastname: Pan
authors.forename: Weiguo
authors.initials: W
authors.lastname: Hu
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tamura
authors.forename: Mohd Erman
authors.initials: ME
authors.lastname: Syazwan
authors.forename: Noritaka
authors.initials: N
authors.lastname: Usami
authors.forename: Seiji
authors.initials: S
authors.lastname: Samukawa