title: Ultraviolet responses of a heterojunction Si quantum dot solar cell.
abstract: We investigated the ultraviolet (UV) responses of a heterojunction Si quantum dot (QD) solar cell consisting of p-type Si-QDs fabricated on a n-type crystalline Si (p-Si-QD/n-c-Si HJSC). The UV responses were compared with a conventional n-type crystalline Si solar cell (n-c-Si SC). The external and internal quantum efficiency results of the p-Si-QD/n-c-Si HJSC exhibited a clear enhancement in the UV responses (300-400 nm), which was not observed in the n-c-Si SC. Based on the results of the cell reflectance and bias-dependent responses, we expect that almost all UV responses occur in the p-Si-QD layer, and the generated carriers can be transported via the Si-QD layer due to the formation of a sufficient electric filed. As a result, a high power conversion efficiency of 14.5% was achieved from the p-Si-QD/n-c-Si HJSC. By reducing the thickness of the n-Si substrate from 650 μm to 300 μm, more enhanced power conversion efficiency of 14.8% was obtained which is the highest value among the reported Si-QD based solar cells to date.
authors.affiliation: Division of Industrial Metrology, Korea Research Institute of Science and Standards, Daejeon, Korea.
authors.forename: Seong Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Gyea Young
authors.initials: GY
authors.lastname: Kwak
authors.forename: Songwoung
authors.initials: S
authors.lastname: Hong
authors.forename: Chanhong
authors.initials: C
authors.lastname: Kim
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
authors.forename: Ansoon
authors.initials: A
authors.lastname: Kim
authors.forename: Kyung Joong
authors.initials: KJ
authors.lastname: Kim