Optical and electrical multilevel storage in organic memory passive matrix arrays

The integration of organic memory diodes, based on photochromic transduction layers, into a simple cross-bar passive matrix array is presented. We show that the high rectification ratios of these diodes successfully suppresses crosstalk effects in these devices, thus avoiding the necessity to integrate additional diodes or transistors. We compare the passive matrix devices' performance to that of non-crossbar reference devices and discuss their performance limitations related to edge effects, which are a consequence of the fabrication process. Finally, we show that the analogue response of the current density to incremental switching of the transduction layer can be used for multi-level programming of the memory elements with no inherent limit to the number of intermediate states. We demonstrate the successful read-out of 8 current levels in a prototype device via both optical and electrical writing procedures. (C) 2014 Elsevier B.V. All rights reserved.