Temperature-Independent Polarization of Ultrathin Phthalocyanine-Based Hybrid Organic/Inorganic Heterojunctions

Autor(es)

Silva, Ricardo M. L. ^{[1, 2]} ; Merces, Leandro ^[1] ; Bof Bufon, Carlos C. ^{[1, 2]}

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: ACS APPLIED MATERIALS & INTERFACES; v. 12, n. 26, p. 29556-29565, JUL 1 2020.
• Citações Web of Science: 0

Resumo

The combination of organic and inorganic materials at the nanoscale to form functional hybrid structures is a powerful strategy to develop novel electronic devices. The knowledge on semiconductor thin-film polarization brings direct benefits to the hybrid organic/inorganic electronics, becoming primordial for the development of devices such as electromechanical logic gates, solar cells, miniaturized valves, organic diodes, and molecular super-capacitors, among others. Here, we report on the dielectric polarization of ultrathin organic semiconducting films-ca. 5 nm thick metal phthalocyanine ensembles (viz., CuPc, CoPc, F16CuPc)-employed to build up hybrid metal/oxide/molecule heterojunctions. Such hybrid heterostructures are fully integrated into self-rolled nanomembrane-based capacitors and further investigated by impedance spectroscopy measurements as a function of temperature (from 6 to 300 K). The dielectric polarization of the metal phthalocyanines is found to be thermally activated above a specific threshold temperature, which depends on the molecular structure. Below this threshold, the current leakage across the system is suppressed, thus evidencing intrinsic-like polarization mechanisms. The temperature-independent permittivities of the ultrathin molecular films are found to be strongly dependent on the organic/inorganic hybrid interfaces, while the calculated relaxation times are more likely related to each single-molecule polarization. Beyond the advances in determining the temperature dependence of the permittivity for ultrathin phthalocyanine films integrated within solid-state electronics, our results also support the deterministic design of novel functional devices based on nanoscale hybrid organic/inorganic heterojunctions. (AU)

• Processo FAPESP: 18/18136-0 - Nanodispositivos híbridos: transporte magnetoeletrônico e desenvolvimento de sensores baseados em moléculas/nanomembranas
• Beneficiário: Leandro das Mercês Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/25979-2 - Fabricação e caracterização de dispositivos e sistemas baseados em nanomembranas híbridas
• Beneficiário: Carlos César Bof Bufon
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 14/50906-9 - INCT 2014: em Materiais Complexos Funcionais (INOMAT)
• Beneficiário: Fernando Galembeck
• Modalidade de apoio: Auxílio à Pesquisa - Temático