title: Core-Shell CdS-Cu₂S Nanorod Array Solar Cells.
abstract: As an earth-abundant p-type semiconductor, copper sulfide (Cu2S) is an attractive material for application in photovoltaic devices. However, it suffers from a minority carrier diffusion length that is less than the length required for complete light absorption. Core-shell nanowires and nanorods have the potential to alleviate this difficulty because they decouple the length scales of light absorption and charge collection. To achieve this geometry using Cu2S, cation exchange was applied to an array of CdS nanorods to produce well-defined CdS-Cu2S core-shell nanorods. Previous work has demonstrated single-nanowire photovoltaic devices from this material system, but in this work, the cation exchange chemistry has been applied to nanorod arrays to produce ensemble-level devices with microscale sizes. The core-shell nanorod array devices show power conversion efficiencies of up to 3.8%. In addition, these devices are stable when measured in air after nearly one month of storage in a desiccator. These results are a first step in the development of large-area nanostructured Cu2S-based photovoltaics that can be processed from solution.
authors.affiliation: †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Andrew Barnabas
authors.initials: AB
authors.lastname: Wong
authors.affiliation: †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Sarah
authors.initials: S
authors.lastname: Brittman
authors.affiliation: †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yu
authors.affiliation: †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.
authors.forename: Neil P
authors.initials: NP
authors.lastname: Dasgupta
authors.affiliation: †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.|‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.|§Kavli Energy Nanosciences Institute, Berkeley, California 94720, United States.|∥Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang
keywords: Nanorod array; copper sulfide; core−shell; photovoltaic; solution processed