title: Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.
abstract: Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells.
authors.affiliation: Laboratory of Organic and Nanostructured Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Paydavosi
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Aidala
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Brown
authors.forename: Pouya
authors.initials: P
authors.lastname: Hashemi
authors.forename: Geoffrey J
authors.initials: GJ
authors.lastname: Supran
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Osedach
authors.forename: Judy L
authors.initials: JL
authors.lastname: Hoyt
authors.forename: Vladimir
authors.initials: V
authors.lastname: Bulović
mesh_terms: D016248:Computer Storage Devices; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D009942:Organometallic Compounds / Q000737:chemistry*; D010316:Particle Size; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D008567:Membranes, Artificial; D009942:Organometallic Compounds; C547306:tris-(8-hydroxyquinoline)aluminum