title: High-throughput fabrication of photoconductors with high detectivity, photosensitivity, and bandwidth.
abstract: Nanocrystalline cadmium selenide (nc-CdSe) was electrodeposited within a sub-50 nm gold nanogap, prepared by feedback-controlled electromigration, to form a photoconductive metal-semiconductor-metal nanojunction. Both gap formation and electrodeposition were rapid and automated. The electrodeposited nc-CdSe was stoichiometric, single cubic phase with a mean grain diameter of ∼7 nm. Optical absorption, photoluminescence, and the spectral photoconductivity response of the nc-CdSe were all dominated by band-edge transitions. The photoconductivity of these nc-CdSe-filled gold nanogaps was characterized by a detectivity of 6.9 × 10(10) Jones and a photosensitivity of 500. These devices also demonstrated a maximum photoconductive gain of ∼45 and response and recovery times below 2 μs, corresponding to a 3 dB bandwidth of at least 175 kHz.
authors.affiliation: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: Wendong
authors.initials: W
authors.lastname: Xing
authors.forename: Sheng-Chin
authors.initials: SC
authors.lastname: Kung
authors.forename: Wytze E
authors.initials: WE
authors.lastname: van der Veer
authors.forename: Wenbo
authors.initials: W
authors.lastname: Yan
authors.forename: Talin
authors.initials: T
authors.lastname: Ayvazian
authors.forename: Jung Yun
authors.initials: JY
authors.lastname: Kim
authors.forename: Reginald M
authors.initials: RM
authors.lastname: Penner
mesh_terms: D004553:Electric Conductivity; D008027:Light; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects*; D010783:Photometry / Q000379:methods*; D011829:Radiation Dosage; D012666:Semiconductors