title: Wafer-scale self-organized InP nanopillars with controlled orientation for photovoltaic devices.
abstract: A unique wafer-scale self-organization process for generation of InP nanopillars is demonstrated, which is based on maskless ion-beam etching (IBE) of InP developed to obtain the nanopillars, where the height, shape, and orientation of the nanopillars can be varied by controlling the processing parameters. The fabricated InP nanopillars exhibit broadband suppression of the reflectance, 'black InP,' a property useful for solar cells. The realization of a conformal p-n junction for carrier collection, in the fabricated solar cells, is achieved by a metalorganic vapor phase epitaxy (MOVPE) overgrowth step on the fabricated pillars. The conformal overgrowth retains the broadband anti-reflection property of the InP nanopillars, indicating the feasibility of this technology for solar cells. Surface passivation of the formed InP nanopillars using sulfur-oleylamine solution resulted in improved solar-cell characteristics. An open-circuit voltage of 0.71 V and an increase of 0.13 V compared to the unpassivated device were achieved.
authors.affiliation: School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, S-164 40 Kista, Sweden.
authors.forename: Reza
authors.initials: R
authors.lastname: Sanatinia
authors.forename: Audrey
authors.initials: A
authors.lastname: Berrier
authors.forename: Veer
authors.initials: V
authors.lastname: Dhaka
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Perros
authors.forename: Teppo
authors.initials: T
authors.lastname: Huhtio
authors.forename: Harri
authors.initials: H
authors.lastname: Lipsanen
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Anand