Electrical switching behaviour of a metalloporphyrin in Langmuir-Blodgett film

Abstract

Abstract Here we report the resistive switching behaviour of an water soluble anionic metalloporphyrin 5,10,15,20-Tetrakis(4-sulfonatophenyl)-21H,23H-porphine manganese(III) chloride (MnTPPS) assembled onto spin coated as well as in Langmuir-Blodgett (LB) film. To prepare LB film, water soluble MnTPPS molecules were incorporated into monolayers of two cationic matrix molecules Octadecyltrimethylammonium bromide (OTAB) and N-Cetyl-N,N,N, trimethyl ammonium bromide (CTAB) through electrostatic interaction. Successful incorporation of MnTPPS molecules into the matrix (OTAB/CTAB) monolayers has been confirmed by measuring π – A isotherm, π – t curve and BAM investigations at air-water interface. From I – V characteristic it was found that by adjusting the measurement protocols (compliance current, sweeping direction) all the devices fabricated by using spin coated as well as LB films exhibit outstanding bipolar switching and threshold switching behaviour at room temperature. Presence of electron acceptor groups (SO3H) and π – electron clouds on the MnTPPS molecules mainly play the crucial role for such observed switching behaviour onto ultrathin films. This type of bipolar memory switching and threshold switching in a single device is technologically very important to use as an active component for the non-volatile information storage and future optoelectronics devices.