Rapid, Wet Chemical Fabrication of Radial Junction Electroluminescent Wires

Abstract

A wet chemical process involving two electrodeposition steps followed by a solution casting step, the "EESC" process, is described for the fabrication of electroluminescent, radial junction wires. EESC is demonstrated by assembling three well-studied nanocrystalline (or amorphous) materials: Au, CdSe, and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The tri-layered device architecture produced by EESC minimizes the influence of an electrically resistive CdSe emitter layer by using a highly conductive gold nanowire that serves as both a current collector and a negative electrode. Hole injection, at a high barrier CdSe-PEDOT:PSS interface (ϕ ≈ 1.1 V), is facilitated by a contact area that is 1.9-4.7-fold larger than the complimentary gold-CdSe electron-injecting contact (ϕ ≈ 0.6 V), contributing to low-voltage thresholds (1.4-1.7 V) for electroluminescence (EL) emission. Au@CdSe@PEDOT:PSS wire EL emitters are 25 μm in length, amongst the longest so far demonstrated to our knowledge, but the EESC process is scalable to nanowires of any length, limited only by the length of the central gold nanowire that serves as a template for the fabrication process. Radial carrier transport within these multishell wires conforms to the back-to-back diode model.

Photoresponse of CdSe-PVA nanocomposite films at low magnetic fields

“…Polymer based semiconducting nanocomposites have attracted enormous interest not only due to their distinctive optical and electronic properties but also due to cost-effectiveness and ease to fabricate devices [1][2][3][4]. In this regard, CdSe nanoparticles (NPs) have shown multiple striking features for relevant applications in various fields including flexible photonic memory [5], photodetectors [6], pressure sensors [7], light emitting diodes [8], solar cells [9], thin film transistors [10], electroluminescent wires [11], photoelectrodes [12], and biomarkers [13]. CdSe is a II-VI group semiconductor with a direct bandgap (Eg) of 1.74 eV (bulk) at 300 K, and shows better quantum yield and photoresponse in comparison to its other group members [3,14].…”