Boileau Nicholas T, Cranston Rosemary, Mirka Brendan, Melville Owen A, Lessard Benoît H
University of Ottawa, Department of Chemical and Biological Engineering 161 Louis Pasteur Ottawa Ontario Canada K1N 6N5
RSC Adv. 2019 Jul 10;9(37):21478-21485. doi: 10.1039/c9ra03648b. eCollection 2019 Jul 5.
Metal phthalocyanines (MPcs) are a widely studied class of materials that are frequently used in organic thin-film transistors (OTFTs), organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs). The stability of these devices and the materials used in their fabrication is important to realize their widespread adoption. Seven P-type MPcs: zinc (ZnPc), magnesium (MgPc), aluminum (AlClPc), iron (FePc), cobalt (CoPc), and titanium (TiOPc) were investigated as the semiconductors in OTFTs under varying temperatures (25 °C to 150 °C) and environmental conditions (air and vacuum, < 0.1 Pa). Devices using the divalent MPcs (except MgPc) showed significant shifts in threshold voltage and field-effect mobility with rising temperature in both air and vacuum. AlClPc and TiOPc, on the other hand, had more stable electrical properties, making them useful for applications requiring consistent performance. Distinct variations in film morphology as determined by atomic force microscopy may explain the different thermal response between the two groups of MPcs, while thermal gravimetric analysis in air and nitrogen (N) provides additional insight into their susceptibility to oxidation at elevated temperature. To demonstrate proof-of-concept thermal sensing under realistic operating conditions, current changes were monitored in response to temperature stimuli using two more sensitive divalent MPcs. This comparative study of the effect of central atom inclusion in MPcs, the resulting material stability and thin-film characteristics will facilitate design of future sensors and other OTFT applications.
金属酞菁（MPcs）是一类被广泛研究的材料，常用于有机薄膜晶体管（OTFTs）、有机光伏电池（OPVs）和有机发光二极管（OLEDs）。这些器件及其制造中所使用材料的稳定性对于实现其广泛应用至关重要。研究了七种P型金属酞菁：锌酞菁（ZnPc）、镁酞菁（MgPc）、铝酞菁氯（AlClPc）、铁酞菁（FePc）、钴酞菁（CoPc）和钛氧基酞菁（TiOPc），将其作为OTFTs中的半导体，在不同温度（25℃至150℃）和环境条件（空气和真空，<0.1 Pa）下进行测试。使用二价金属酞菁（除MgPc外）的器件在空气和真空中，随着温度升高，阈值电压和场效应迁移率均出现显著变化。另一方面，AlClPc和TiOPc具有更稳定的电学性能，使其适用于需要稳定性能的应用。通过原子力显微镜确定的薄膜形态的明显差异，可能解释了两组金属酞菁之间不同的热响应，而在空气和氮气（N）中的热重分析则进一步深入了解了它们在高温下的氧化敏感性。为了在实际操作条件下证明热传感的概念验证，使用另外两种更灵敏的二价金属酞菁监测了响应温度刺激的电流变化。这项关于金属酞菁中中心原子包含效应、由此产生的材料稳定性和薄膜特性的比较研究，将有助于未来传感器和其他OTFT应用的设计。
