LNNano - Brazilian Nanotechnology National Laboratory

Rectification ratio and direction controlled by temperature in copper phthalocyanine ensemble molecular diodes

 

Carolina Sergi Lopes, Leandro Merces, Rafael Furlan de Oliveira, Davi Henrique Starnini de Camargo, Carlos César Bof Bufon

Abstract
Organic diodes and molecular rectifiers are fundamental electronic devices that share one common feature: current rectification ability. As both present distinct spatial dimensions and working principles, the rectification of organic diodes is usually achieved by interface engineering, while the molecular rectifiers’ features are commonly controlled by changes in molecular structures. In this work, we report on the first observation of temperature-driven inversion of the rectification direction (IRD) in ensemble molecular diodes (EMDs). The EMDs are composed of 20 nm thick molecular ensembles of copper phthalocyanine in close contact with one of its fluorinated derivatives. Here, the organic/organic interface was found responsible for altering the junction’s charge conduction mechanisms. The temperature has played a crucial role for each transport transition, which we have investigated via electrical measurements and band diagram analysis, thus providing the fundamentals on the IRD occurrence. Our findings represent an important step towards simple and rational control of rectification in carbon-based electronic nanodevices.

Keywords: Organic diodes, molecular rectifiers, electronic junctions, charge transport, nanomembranes

Research article: Rectification ratio and direction controlled by temperature in copper phthalocyanine ensemble molecular diodes, Nanoscale, 2020.
Direct link: https://doi.org/10.1039/C9NR10601D