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

Author(s)

Lopes, Carolina Sergi ^[1] ; Merces, Leandro ^[1] ; de Oliveira, Rafael Furlan ^[1] ; Starnini de Camargo, Davi Henrique ^{[1, 2]} ; Bof Bufon, Carlos Cesar ^{[1, 2, 3]}

Affiliation

^[1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Postgrad Program Mat Sci & Technol POSMAT, BR-17033360 Bauru, SP - Brazil

^[3] Univ Estadual Campinas, Dept Phys Chem, Inst Chem IQ, BR-13084862 Campinas, SP - Brazil

• Document type: Journal article
• Source: NANOSCALE; v. 12, n. 18, p. 10001-10009, MAY 14 2020.
• Web of Science Citations: 0

Abstract

Organic diodes and molecular rectifiers are fundamental electronic devices that share one common feature: current rectification ability. Since both present distinct spatial dimensions and working principles, the rectification of organic diodes is usually achieved by interface engineering, while changes in molecular structures commonly control the molecular rectifiers' features. Here, we report on the first observation of temperature-driven inversion of the rectification direction (IRD) in ensemble molecular diodes (EMDs) prepared in a vertical stack configuration. The EMDs are composed of 20 nm thick molecular ensembles of copper phthalocyanine in close contact with one of its fluorinated derivatives. The material interface was found to be responsible for modifying the junction's conduction mechanisms from nearly activationless transport to Poole-Frenkel emission and phonon-assisted tunneling. In this context, the current rectification was found to be dependent on the interplay of such distinct charge transport mechanisms. The temperature has played a crucial role in each charge 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. (AU)

• FAPESP's process: 16/25346-5 - Capacitive devices for hybrid nanostructures characterization: study of electrical properties of surface metal-organic frameworks -SURMOFs- and metallophthalocyanines
• Grantee: Tatiana Parra Vello
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/25979-2 - Fabrication and characterization of devices and systems based on hybrid nanomembranes
• Grantee: Carlos César Bof Bufon
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 14/50906-9 - INCT 2014: in Functional Complex Materials
• Grantee: Fernando Galembeck
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/18136-0 - Hybrid nanodevices: magnetoelectronic transport and development of sensors based on molecules/nanomembranes
• Grantee: Leandro das Mercês Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral