Photochromic Transduction Layers in Organic Memory Elements

Abstract

Photochromic molecules provide an intriguing and relatively untapped alternative to traditional materials utilized in organic memory devices. Here, we review recent progress in the implementation of photochromic molecules in electrically-addressed organic memory devices. Recent results for a lightemitting photochromic organic diode are highlighted in the context of multifunctional devices with the ability to simultaneously operate as multilevel memory, signage and display elements. Furthermore, a set of design rules for successful implementation of photochromic compounds in organic memory devices are suggested.

Optically switchable transistors by simple incorporation of photochromic systems into small-molecule semiconducting matrices

“…5a,b; blue plots) originating from photogenerated carriers. Noteworthy, it appears that no ring closure due to current flow is occurring in bi-component films, in contrast to previous observations on neat films of photochromic moieties in vertical geometries 4,24 . This is supported by comparing single-and bicomponent film devices (see Supplementary Fig.…”

“…O rganic optoelectronic materials 1 attract particular attention for the development of low-cost multifunctional devices, such as phototransistors 2 and optical memories 3,4 . In these devices, the light is used as a remote control to modulate electrical properties.…”

OFET‐Based Memory Devices Operating via Optically and Electrically Modulated Charge Separation between the Semiconductor and 1,2‐bis(Hetaryl)ethene Dielectric Layers

“…[1][2][3][4] A phototriggered isomerization of the most common photochromes between two quasistable isomeric forms changes signifi cantly their fundamental electronic and electrical properties such as frontier energy levels, electrical conductivity, dipole moment, dielectric constant, etc. [ 5,6 ] This effect enables realizing new exiting functionalities in organic fi eld-effect transistors (OFETs), diodes, and light-emitting devices.…”

“…[ 13 ] Unfortunately, the photoswitching effects achieved in the diode-type memory elements were not very strong which stimulated exploration of other concepts, including the application of graphene-based materials. [1][2][3][4]14 ] Organic fi eld-effect transistors modifi ed with photochromic molecules were extensively investigated in order to construct memory elements with enhanced optical switching characteristics. The reported OFET structures comprised some photochromic material as a dopant in a semiconductor layer, [15][16][17][18][19][20] as a buffer layer between semiconductor and source/ drain electrodes, [ 21,22 ] and as an interfacial layer between wileyonlinelibrary.com Various functionalized bis(heteroaryl)ethenes represent a promising group of photochromic materials for designing organic memory elements (see examples in entries 10-17, Table S1, Supporting Information).…”

Electronic Properties of Optically Switchable Photochromic Diarylethene Molecules at the Interface with Organic Semiconductors

“…[2,3] Due to the photochromism, these molecules can switch reversibly between two isomers by light irradiation with different wavelengths. [4][5][6][7] Switching between the two isomers fundamentally changes the electronic properties of the molecules, e.g., the optical gap, molecular dipole moment, molecular electron affinity, and ionization energy.…”