A new light-responsive resistive random-access memory device containing hydrogen-bonded complexes
Document Type
Article
Publication Date
1-1-2021
Abstract
In the search to obtain new and more efficient components of memory devices, we report the photochromic, dielectric and electrochemical response of a light-responsive organic compound, and its memory performance under electrical fields. The so-called N(1)-[12-(4-(4′-isobutyloxyphenyldiazo)phenoxy)dodecyloxy)]thymine, tAZOi, molecule contains one azobenzene group, which provides with photochromic character, and one terminal thymine group, capable to form hydrogen bonds and assemble supramolecular dimers, (tAZOi)2. We have calculated the optical absorption coefficient, extinction coefficient and refractive index of tAZOi, which obeys the single oscillator Wemple–DiDomenico model. An ITO/tAZOi/Al device has been prepared and presents two switchable conductance states with preservation of memory performance. The mechanism linked to the resistive random-access memory (RRAM) has been evaluated by molecular modelling and is controlled by p-type conduction, possibly involving hydrogen-bonding. Upon UV irradiation at ∼ 365 nm, tAZOi displays an increase in the complex permittivity driven by trans-to-cis (E-to-Z) isomerisation of the azobenzene groups. Molecular simulations suggest that conductivity and device performance can be enhanced (and controlled) by light exposure through the formation of activated Z isomers that could transfer charge to other neighbouring molecules, resulting in photo-electric responsive devices. © 2020 Elsevier B.V.
Keywords
Azobenzene, Photochromic molecules, Hydrogen-bonding, Dielectric spectroscopy, Conductivity, Memory device
Divisions
PHYSICS,InstituteofBiologicalSciences,CHEMISTRY
Funders
Ministry of Higher Education of Malaysia through the Fundamental Research Grant Scheme [ FP079-2018A ],Ministerio de Economía y Competitividad (MINECO) for PhD grant BES-2015-071235, under the project MAT2014-55205-P,University Malaya for the grant RF004B-2018,Royal Academy of Engineering, U.K., for the grant NRCP1516/4/61 (Newton Research Collaboration Programme),University of Aberdeen, for the award of the grant SF10192,Carnegie Trust for the Universities of Scotland, for the Research Incentive Grant RIG008586,Royal Society and Specac Ltd. , for the Research Grant RGSR1201397,Royal Society of Chemistry for the award of a mobility grant ( M19-0000 )
Publication Title
Journal of Photochemistry and Photobiology A: Chemistry
Volume
404
Publisher
Elsevier