title: Factors affecting the stability and performance of ionic liquid-based planar transient photodetectors.
abstract: A novel planar architecture has been developed for the study of photodetectors utilizing the transient photocurrent response induced by a metal/insulator/semiconductor/metal (MISM) structured device, where the insulator is an ionic liquid (IL-MISM). Using vanadyl 2,3-naphthalocyanine, which absorbs in the communications-relevant near-infrared wavelength region (λ(max,film) ≈ 850 nm), in conjunction with C60 as a bulk heterojunction, the high capacitance of the formed electric double layers at the ionic liquid interfaces yields high charge separation efficiency within the semiconductor layer, and the minimal potential drop in the bulk ionic liquid allows the electrodes to be offset by distances of over 7 mm. Furthermore, the decrease in operational speed with increased electrode separation is beneficial for a clear modeling of the waveform of the photocurrent signal, free from the influence of measurement circuitry. Despite the use of a molecular semiconductor as the active layer in conjunction with a liquid insulating layer, devices with a stability of several days could be achieved, and the operational stability of such devices was shown to be dependent solely on the solubility of the active layer in the ionic liquid, even under atmospheric conditions. Furthermore, the greatly simplified device construction process, which does not rely on transparent electrode materials or direct electrode deposition, provides a highly reproducible platform for the study of the electronic processes within IL-MISM detectors that is largely free from architectural constraints.
authors.affiliation: ∥Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa, 464-8601 Nagoya, Japan.
authors.forename: Simon
authors.initials: S
authors.lastname: Dalgleish
authors.forename: Louisa
authors.initials: L
authors.lastname: Reissig
authors.affiliation: ⊥Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China.
authors.forename: Laigui
authors.initials: L
authors.lastname: Hu
authors.forename: Michio M
authors.initials: MM
authors.lastname: Matsushita
authors.affiliation: #Division of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kitaku, 700-8530 Okayama, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sudo
authors.forename: Kunio
authors.initials: K
authors.lastname: Awaga
mesh_terms: D004566:Electrodes; D052578:Ionic Liquids / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids