Fully Integrated Organic Nanocrystal Diode as High Performance Room Temperature NO₂ Sensor

Abstract

Organic diodes consisting of molecular nano-pyramid structures sandwiched between metal and strained nano-membrane electrodes are created. The robust and smooth contacts provided by self-curled metal layers render the molecular nano-pyramids efficent channels for detecting nitrogen dioxide airflow.

Charge transport in organic nanocrystal diodes based on rolled-up robust nanomembrane contacts

“…The fabrication protocol of the organic nanocrystal diodes is the same as in our previous reports [19]. The fabrication yield of the devices contacted by rolled-up electrodes on the single chip can achieve more than 95% owing to the reliable parallel nanofabrication when the whole process is carefully performed.…”

“…Thus, the fabrication of a reliable robust top contact is expected to solve this tedious problem. Part of the authors of this report have developed a novel ‘rolled-up nanotechnology’ to tackle this challenge [17–19]. By this method, strained nanomembranes are released from a substrate surface and the elastic relaxation of the built-in strain gradient triggers a self-rolling process of the nanomembranes.…”

“…By this method, strained nanomembranes are released from a substrate surface and the elastic relaxation of the built-in strain gradient triggers a self-rolling process of the nanomembranes. The strained nanomembranes roll-up into full microtubes and finally land on top of the organic nanostructures, e.g., self-assembled monolayers and organic nanopyramids [17,19]. Compared to other ‘soft’ contact methods developed recently, including chemical binding [20–21], indirect evaporation [22–23], ‘ready-made’ approaches [24–25], and robust mechanical contacts [26–29], the rolled-up nanotechnology provides the precise positioned electrodes and high fabrication yield of array devices, and does not require the chemical modification of functional organic layers.…”

“…Furthermore, the candidate materials for rolled-up nanomembranes are metals, ferromagnetic layers, oxides, and complex materials, of which the various properties of thin solid films, e.g., work function and magnetic properties, can be utilized to develop novel functional organic devices [30–31]. In our previous report, organic nanocrystal diodes have been successfully developed, in which rolled-up nanomembranes provide robust contacts to fully unleash the advantages of organic nanocrystals for sensing gas molecules [19]. Apart from the demonstration of functional nanodevices, the investigation and understanding of charge transport mechanisms across the organic nanostructure is a key topic nowadays for developing and optimizing novel nanostructured devices [8–9 32–33].…”

Achievement of High-Response Organic Field-Effect Transistor NO2 Sensor by Using the Synergistic Effect of ZnO/PMMA Hybrid Dielectric and CuPc/Pentacene Heterojunction

“…One of the most common and detrimental air pollutant oxidizing gases is nitrogen oxides, including nitrogen dioxide (NO 2 ), which is produced and released into atmosphere from combustion and automotive emission. In addition to contributing to the formation of fine particle pollution, NO 2 is linked with a number of adverse effects on the respiratory system such as chronic bronchitis, emphysema, and respiratory irritation at low concentrations [2,3,4]. The potential detrimental impact of NO 2 emission on public health and the environment has led to extensive scientific and technological progress in the field of NO 2 sensors.…”